Because of the modulation of an AMD chip using multi-chip module design, I would expect DDR-5 to be up to 10 x faster than DDR-4 on an AMD chip. The multi-chip modules should be able to consume much more bandwidth while at the same time using a new memory controller to really spruce things up. I once used 386 class of computer. Upgrading to the 486 class was very good and a big part was because of the new memory. Also, won't these new DDR-5 modules be up to double memory per chip? Could we not see 128GB memory chips in DDR-5?
This is the same guy that has been posting over and over again on Intel laptop chips insisting that they're slower than Big Navi. He's an obvious troll.
Exactly. The guy is obviously trolling. I like AMD a lot, but you aren't magically going to get any faster bandwidth out of DDR5 on an AMD chip just because it is the foster child of Lisa Su.
He's actually quite intelligent and an Intel fan (possibly Nvidia too). When he's in character, he portrays the archetypal fan, an AMD one, in order to run AMD down, that they're inferior, second-rate, a budget option, able to run Diablo and AoE 2, etc. It's also to lower the true AMD fan, as portraying a caricatured version of how one of them would supposedly speak. As the chap in Silencio said, "it's all an illusion."
At any rate, I actually enjoy his (or her) comments. He comes up with a pretty different angle of looking at stuff. And no, I'm not a duplicate account of his trying to chime in.
Based on the fact that they claim to believe that the account is an actual AMD fan, it's more likely that Showtime is a duplicate account, TBH. That or they're not as smart as they think they are. 🤷♂️
His thinly veiled disguise as an AMDfan has been a poor attempt to create drama. It's obvious he's the opposite trying to make a mockery of AMD. I dont find it amusing, surprised he hasn't yet been banned.
Yes, 10x faster! If anyone would know, it's AMDSuperFan! LOL
While I did not intentionally do it, I'm going to end up skipping the entire DDR4 generation and going straight from DDR3 (3570K) to DDR5 (AM5/LGA-1700).
I'm probably going to end up doing the same, having also skipped DDR2 on my primary systems. If I do end up with DDR4 in anything, it'll probably be a new laptop. (My 2015 XPS13 is on it's 4th battery having bulged 2 in about a year each and having a 3rd just stop holding charge all together after about the same amount of time. If it kills this one, I'm probably going to replace the entire system.)
do you run your batteries down often? or do you keep your laptop plugged in almost always? keeping any brand laptop plugged in often and not cycling the battery kills batteries. (any brand)
This is not really true. Until recently I had a 5-year-old Skylake gaming laptop that's pretty much always used plugged in. It still got more than an hour on battery and - more crucially - the battery hasn't bulged.
Modern battery control circuitry should (and can) handle these use cases just fine.
10x is definitely overestimation, twice the bandwidth, twice the capacity, under load MAYBE we will get 250% on memory bound tasks, but that's it. General performance will not go beyond 30%, maybe 60% on igpu's. one thing I am happy about is no more 4GB versions, they will make it in 8GB sticks (16GB hopefully) or higher.
Is there any chance you can make the comment section work better? Something like Reddit or just like the forums of anandtech. It's hard to follow sometimes who is talking to who when a comment string goes over 2, 3 or 4 pages.
Dr. Ian - yes 10 x faster. Think about it. AMD use chiplet design. Each chiplet, if able to access each directly through the infinity controller, we should see ~ 2.5X per chiplet. So yes, x 4 chiplets, AMD should now be 10x faster for memory.
What AMD motherboard can I buy that takes these 256GB modules or even 128GB modules? If I can get 1TB of RAM, perhaps I will upgrade from what I was thinking.
This is one of several mobos that have AMD processors and 1TB of RAM support. Of course you will probably argue that you meant a consumer board, and I will laugh at that.
They're an Intel / nVidia fanboy pretending to be an AMD fan in some sort of weird attempt to make people who don't worship those organisations look bad.
Shilly lil fanboy the numbers don't support your claims. They never seem to support your theories/agenda. Do you game, or just multi bs all day? Are Intels still giving more FPS than AMD in gaming? Uh huh. Did AMD make something to replace my 3 year old 1080 ti with yet?
Can we get this guy banned. This isn't fucking reddit AyMD.
Can we get this AyMDer banned. Getting old having to correct his non sense on every article.
It's amazing the number of people that read this troll's asinine posts and yet take their username literally. The funny bit is that for an account that's supposed to make AMD fans look bad, all it ends up doing is make their detractors look painfully credulous for believing that it is, in fact, an AMD fan.
With VRMs in the memory modules, should we now expect higher heat output from there? Will RAM modules come with larger heatspreaders more often? If that's the case, has the minimum spacing between DDR5 modules in motherboards been revised?
>should we now expect higher heat output from there? Probably. This is coupled with a voltage reduction on the memory as well, so as long as the VRMs are efficient, it should be ok.
>Will RAM modules come with larger heatspreaders more often? If that's the case, has the minimum spacing between DDR5 modules in motherboards been revised? As far as I can tell, the spacing is the same. Most enthusiast modules have overkill heatspreaders anyway - the 128 GB DDR4 LRDIMMs get a lot more toasty and they come without heatspreaders (though good airflow is a must).
Heat is actually quite good for speed. Molecules travel much faster with heat. To test this, put ice cream on a plate, and turn the plate at a 45 degree angle. You will notice that the ice cream barely moves, but heat it up. You will notice that now, the ice cream move very fast off of this plate. You will also note that when chips are hotter, they are running faster. Most people assume that they are hot because they are running faster, but the opposite is true in my experience and within the laws of thermo-dynamics. That said, why would you want to slow down your memory by getting it colder?
Higher heat also causes certain more memory errors though. They isn't as big of a deal ECC. But many many many kits won't have ECC as it's artificially market segmented particularly by Intel for mostly server boards and chips. There's a reason the heat is spread out with heatspreaders on consumer oriented kits. Server kits tend to be bare because of the high rpm fans brute forcing air through the chassis. But heat absolutely can cause memory errors. So the context matters. Your post works well in a sterile physics way but you have to also consider in practice, in field, with the actual product and technology.and setups and issues. I'm not talking about "some" heat but excessive heat, poorly ventilated, etc non-ECC DIMMs.
Superconductor behaviour is very different to semiconductor behaviour. Superconductors have no resistance and thus no power loss. That's a separate discussion to the actual speed of the electrons in a semiconductor.
This looks like something that will take a while coming to consumer-grade products. Might come more quickly to laptops that will capitalize on the power savings, though--but that depends on cost, I should think.
Intel do have a long-standing habit of getting consumers to foot some of the early adoption tax for new memory technology. Tiger Lake already has support for LPDDR5, which is rumoured to be hitting products some time early next year - it does at least make sense there due to the potential power of its iGPU (driver issues notwithstanding).
Looking at these specifications makes me wish there was a higher power variant of the ddr spec. I feel like the continuous push for lower power makes these latencies as high as they are. While I do understand laptops and servers having more benefits from lower power the desktop space generally would not care too much about it and would mostly benefit from lower latency. The difference in latencies between xmp profiles and stock on modern memory are really high. Most memory and memory controllers can handle quite a bit higher voltages than the spec calls for. With these voltages latencies could be reduced and it would be easier to reach higher speeds.
Sadly the desktop segment is not the largest so probably not the biggest consideration at least not anymore.
I have to point out that 12 Nanoseconds at the speed of light is 3.598 meters (11.8 ft). This seems like a lot when the entire memory trace of a motherboard might be 0.3 m or about a foot. But when you account for clock instability and manufacturing tolerance, we are getting closer and closer to the constraints set by physics. I wouldn't be surprised if that lower floor of ~14ns we see in the specs has more to do with the limitations of the connectors, traces, and motherboard materials than it does with what the chips and memory controllers could do if they were directly soldered together.
Thanks for the info, that makes me more impressed with the latencies we see on the top end of the enthusiast RAM market. I would love to hear from a memory system engineer to see what they think about being able to go lower latency over higher bandwidth.
Many modern system RAM chips are indeed soldered in.
Apple was probably the first to do it on high-end laptops, but other companies followed suit. Nowadays the vast majority of fast systems have soldered in RAM chips - iPads, iPhones, Samsung Galaxies, Microsoft Surface Pro, Macbook Air, Macbook Pro, Google Pixels, many high end Chromebooks, the list goes on.
It doesn't seem to have led to any reduction in latency that I know of.
the issue isn't really power but cost. They've made/make variants of DRAM with much lower latencies but the raw cost per GB is almost an order of magnitude higher than with commodity dram. for most of the market, ~10ns array latency hits the sweet spot on cost vs performance.
Not so much a comment on DDR5, but more on memory speeds in general: I am (still) amazed that non-volatile NAND in fast PCIe4 SSDs basically reaches bandwidth numbers of working memory from about 10-15 years ago. IMHO, that's real progress. Now, if AMD and Intel could give us four memory channels for their APUs, we'd be cooking! Even on DDR4 3200, four channels should feed those iGPUs of Renoirs and Tiger Lake a lot better. Hey, I can always ask and dream..
Bandwidth is easy: Just put enough platters of spinning rust in parallel and you can hit 50GB/s. But should you try to run your game on an NVMe instead of DRAM, it won't be a lot of fun because latencies pile up.
Reminds me of fixed head drives or even magnetic drums being used as fast swap devices in the 1960's for DRAM that counted in KWords. But those were running batch jobs where managing locality was hopefully easier.
I'm not sure the economics of it works out. Between the larger die area and increase in motherboard complexity, you end up pumping more cost into something that will be beaten senseless by an inexpensive add-in board.
The only market in which it makes sense is ones where that board isn't an option - e.g. highly integrated systems - and I don't know that there's a lot of demand for significantly higher GPU performance there (yet).
iPhones, iPads, high-end androids, chromebooks, laptops (Macbooks, Surface Pro, Apple's new ARMbooks), game consoles, VR headsets? There's a lot of demand for highly integrated systems with high RAM / storage / CPU performance.
JEDEC went through a lot of trouble to push that much bandwidth over long PCB traces.
We've enjoyed discrete memory/logic for a long time, but the traces just have to get shorter. Integrated packages, with memory stacked next to or under the CPU, are the way forward.
Some customers will always need enormous pools, but they can use specialized products. Perhaps they'll start using silicon photonics for memory buses at the very top end.
13nm latency... light IN VACUUM can travel only 39cm in this time, in wires the electrical field is slower. Basically, since DDR3 the latency is limited by physical design of DIMMs separately on the motherboard, with complex routing. And the only improvement can come also from physical design, smaller SO-DIMM slots need to be on the CPU package (say, on the sides) for the shortest possible paths (would also improve energy efficiency due to lower noise in shorter routes).
Ian, or any site managers, I plead for removing/collapsing obvious trolls inside the comment area. Otherwise the first few pages is flooded just because a single troll made it to the first.
Not quite. Bandwidth increases with frequency, and that's scaling pretty well. Latency is stagnant. So it's like a more powerful engine giving more top speed, but the 0-60 acceleration times are still the same.
Marketing "speed" crap aside, they do bring some benefits: - transceivers are tuned for finer geometries which are needed for high capacities - a bit lower energy useage - greater bandwith will be great for APUs and perhaps some manycores, like TR x9990 etc.
Just a reminder that whenever a new standard of DDR comes out it is the same as the faster older version of DDR. You don't get the true advantages till it has been around a few years and the faster speeds become available. So if you're waiting for DDR5 to build a new PC, don't bother, it's going to be a super long wait.
I wonder what moving the voltage regulator onto the RAM module will do for enthusiasts. Will overclockers still be able to adjust the voltage levels? Will there be an industry standard for the BIOS/system to instruct the RAM what voltage it should run at?
Good question. I'd be amazed if they didn't find a way to make voltage adjustments available to the end-user, but it'll certainly be interesting to see how that's handled.
The tables with A B C timings and with A timings have three columns for CL, which are always the same; you could squash them to one column. It would be clearer if there were columns for A, B, and C with subcolumns for CL cycles and CL ns. Then you could collapse the A B C lines to one line, and eliminate the separate A table.
Dumb question time, but it looks like DDR4 3200 performs identicaly with DDR5 3200, though I do note that the DDR5 spec does go up to higher speeds.
What, fundamentally, is being changed between the ram generations? Is it just changes in the way it runs to allow higher effective speeds to be possible?
I think I'm just not seeing why there seems to be so much hype around each ram generation, past DDR.
I'm missing something here: DDR3 CL9@1600MHz with 11.25ns latency. DDR4 CL14@3600MHz with 7.77ns latency. DDR4 CL15@4000MHz with 7.50ns latency DDR4 CL16@4400MHz with 7.27ns latency DDR4 CL18@4600MHz with 7.83ns latency
That is almost half of the 13~14ns mentioned in the article. DDR5 would have double the latency compared to the fastest DDR4. The interesting part with DD5 is the Burst Length (BL16) having 64 bytes prefetch. This could make L2 cache misses less expensive.
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AMDSuperFan - Tuesday, October 6, 2020 - link
Because of the modulation of an AMD chip using multi-chip module design, I would expect DDR-5 to be up to 10 x faster than DDR-4 on an AMD chip. The multi-chip modules should be able to consume much more bandwidth while at the same time using a new memory controller to really spruce things up. I once used 386 class of computer. Upgrading to the 486 class was very good and a big part was because of the new memory. Also, won't these new DDR-5 modules be up to double memory per chip? Could we not see 128GB memory chips in DDR-5?Ian Cutress - Tuesday, October 6, 2020 - link
10x faster? huh?On capacity, we've addressed that a few times, most recently in the post earlier today that's in the link in the first sentence of this post: https://www.anandtech.com/show/16142/ddr5-is-comin...
SarahKerrigan - Tuesday, October 6, 2020 - link
This is the same guy that has been posting over and over again on Intel laptop chips insisting that they're slower than Big Navi. He's an obvious troll.drexnx - Tuesday, October 6, 2020 - link
obvious troll or actually insane? at this point to me it's not clear.the sheer gibberish they post really can't be neatly defined as either...
Showtime - Tuesday, October 6, 2020 - link
He needs to be banned. This isn't AYMD on reddit. Bad enough with all the misinformation I read every else.Hifihedgehog - Tuesday, October 6, 2020 - link
Exactly. The guy is obviously trolling. I like AMD a lot, but you aren't magically going to get any faster bandwidth out of DDR5 on an AMD chip just because it is the foster child of Lisa Su.GeoffreyA - Wednesday, October 7, 2020 - link
He's actually quite intelligent and an Intel fan (possibly Nvidia too). When he's in character, he portrays the archetypal fan, an AMD one, in order to run AMD down, that they're inferior, second-rate, a budget option, able to run Diablo and AoE 2, etc. It's also to lower the true AMD fan, as portraying a caricatured version of how one of them would supposedly speak. As the chap in Silencio said, "it's all an illusion."At any rate, I actually enjoy his (or her) comments. He comes up with a pretty different angle of looking at stuff. And no, I'm not a duplicate account of his trying to chime in.
Spunjji - Wednesday, October 7, 2020 - link
Based on the fact that they claim to believe that the account is an actual AMD fan, it's more likely that Showtime is a duplicate account, TBH. That or they're not as smart as they think they are. 🤷♂️GeoffreyA - Wednesday, October 7, 2020 - link
Good thinking. Never thought of that :)Hixbot - Wednesday, October 7, 2020 - link
His thinly veiled disguise as an AMDfan has been a poor attempt to create drama. It's obvious he's the opposite trying to make a mockery of AMD. I dont find it amusing, surprised he hasn't yet been banned.Hifihedgehog - Tuesday, October 6, 2020 - link
> actually insane?Option B.
I was like...
Bwahahaha.
RAM is RAM. Don't expect AMD to magically make it faster unless they introduce 16- and 32-channel memory controllers.
Now, that would be cool. Don't expect a Franken-chip like that on any client platform, though.
nathanddrews - Tuesday, October 6, 2020 - link
Yes, 10x faster! If anyone would know, it's AMDSuperFan! LOLWhile I did not intentionally do it, I'm going to end up skipping the entire DDR4 generation and going straight from DDR3 (3570K) to DDR5 (AM5/LGA-1700).
ingwe - Tuesday, October 6, 2020 - link
Yeah the username does kinda give it away...dotjaz - Wednesday, October 7, 2020 - link
No, a fan is not insane.DanNeely - Tuesday, October 6, 2020 - link
I'm probably going to end up doing the same, having also skipped DDR2 on my primary systems. If I do end up with DDR4 in anything, it'll probably be a new laptop. (My 2015 XPS13 is on it's 4th battery having bulged 2 in about a year each and having a 3rd just stop holding charge all together after about the same amount of time. If it kills this one, I'm probably going to replace the entire system.)six_tymes - Tuesday, October 6, 2020 - link
do you run your batteries down often? or do you keep your laptop plugged in almost always? keeping any brand laptop plugged in often and not cycling the battery kills batteries. (any brand)Spunjji - Wednesday, October 7, 2020 - link
This is not really true. Until recently I had a 5-year-old Skylake gaming laptop that's pretty much always used plugged in. It still got more than an hour on battery and - more crucially - the battery hasn't bulged.Modern battery control circuitry should (and can) handle these use cases just fine.
deil - Wednesday, October 7, 2020 - link
10x is definitely overestimation, twice the bandwidth, twice the capacity, under load MAYBE we will get 250% on memory bound tasks, but that's it. General performance will not go beyond 30%, maybe 60% on igpu's.one thing I am happy about is no more 4GB versions, they will make it in 8GB sticks (16GB hopefully) or higher.
steve wilson - Wednesday, October 7, 2020 - link
Is there any chance you can make the comment section work better? Something like Reddit or just like the forums of anandtech. It's hard to follow sometimes who is talking to who when a comment string goes over 2, 3 or 4 pages.AMDSuperFan - Wednesday, October 7, 2020 - link
Dr. Ian - yes 10 x faster. Think about it. AMD use chiplet design. Each chiplet, if able to access each directly through the infinity controller, we should see ~ 2.5X per chiplet. So yes, x 4 chiplets, AMD should now be 10x faster for memory.Unashamed_unoriginal_username_x86 - Tuesday, October 6, 2020 - link
...?? Do you think they'll have 5x as many memory controllers? Also don't chiplets degrade DRAM performance by reducing peak fabric speed?DiHydro - Tuesday, October 6, 2020 - link
I don't know what you specifically mean by 128GB memory chips, but DDR4 RAM modules already reached 256GB per stick in 2018.AMDSuperFan - Tuesday, October 6, 2020 - link
What AMD motherboard can I buy that takes these 256GB modules or even 128GB modules? If I can get 1TB of RAM, perhaps I will upgrade from what I was thinking.DiHydro - Tuesday, October 6, 2020 - link
If you are such a super fan, you sure don't know a lot about the products AMD is offering right now...https://www.newegg.com/supermicro-h11ssl-i-single-...
This is one of several mobos that have AMD processors and 1TB of RAM support. Of course you will probably argue that you meant a consumer board, and I will laugh at that.
Spunjji - Wednesday, October 7, 2020 - link
They're an Intel / nVidia fanboy pretending to be an AMD fan in some sort of weird attempt to make people who don't worship those organisations look bad.AMDSuperFan - Wednesday, October 7, 2020 - link
I am talking about consumer boards.Showtime - Tuesday, October 6, 2020 - link
Shilly lil fanboy the numbers don't support your claims. They never seem to support your theories/agenda. Do you game, or just multi bs all day? Are Intels still giving more FPS than AMD in gaming? Uh huh. Did AMD make something to replace my 3 year old 1080 ti with yet?Can we get this guy banned. This isn't fucking reddit AyMD.
Can we get this AyMDer banned. Getting old having to correct his non sense on every article.
Spunjji - Wednesday, October 7, 2020 - link
It's amazing the number of people that read this troll's asinine posts and yet take their username literally. The funny bit is that for an account that's supposed to make AMD fans look bad, all it ends up doing is make their detractors look painfully credulous for believing that it is, in fact, an AMD fan.GeoffreyA - Thursday, October 8, 2020 - link
Agreed; that's what stunned me.StevoLincolnite - Tuesday, October 6, 2020 - link
Yeah... Just get rid of the troll. 10x faster? Give me a break.tipoo - Tuesday, October 6, 2020 - link
Only if they use Big Navi as the memory controller, eh Fan?dotjaz - Wednesday, October 7, 2020 - link
Insane troll.ToTTenTranz - Tuesday, October 6, 2020 - link
With VRMs in the memory modules, should we now expect higher heat output from there? Will RAM modules come with larger heatspreaders more often? If that's the case, has the minimum spacing between DDR5 modules in motherboards been revised?Ian Cutress - Tuesday, October 6, 2020 - link
>should we now expect higher heat output from there?Probably. This is coupled with a voltage reduction on the memory as well, so as long as the VRMs are efficient, it should be ok.
>Will RAM modules come with larger heatspreaders more often? If that's the case, has the minimum spacing between DDR5 modules in motherboards been revised?
As far as I can tell, the spacing is the same. Most enthusiast modules have overkill heatspreaders anyway - the 128 GB DDR4 LRDIMMs get a lot more toasty and they come without heatspreaders (though good airflow is a must).
AMDSuperFan - Tuesday, October 6, 2020 - link
Heat is actually quite good for speed. Molecules travel much faster with heat. To test this, put ice cream on a plate, and turn the plate at a 45 degree angle. You will notice that the ice cream barely moves, but heat it up. You will notice that now, the ice cream move very fast off of this plate. You will also note that when chips are hotter, they are running faster. Most people assume that they are hot because they are running faster, but the opposite is true in my experience and within the laws of thermo-dynamics. That said, why would you want to slow down your memory by getting it colder?quorm - Tuesday, October 6, 2020 - link
I appreciate the commitment to the bit.Spunjji - Wednesday, October 7, 2020 - link
Yeah, this one was genuinely funny.Wilco1 - Tuesday, October 6, 2020 - link
You should test this by setting your computer on fire and see whether it runs any faster.bcronce - Tuesday, October 6, 2020 - link
Rockets have plaid mode, but computers have plasma mode.JfromImaginstuff - Wednesday, October 7, 2020 - link
This is probably my favourite comment in all of anadtechCheapSushi - Tuesday, October 6, 2020 - link
Higher heat also causes certain more memory errors though. They isn't as big of a deal ECC. But many many many kits won't have ECC as it's artificially market segmented particularly by Intel for mostly server boards and chips. There's a reason the heat is spread out with heatspreaders on consumer oriented kits. Server kits tend to be bare because of the high rpm fans brute forcing air through the chassis. But heat absolutely can cause memory errors. So the context matters. Your post works well in a sterile physics way but you have to also consider in practice, in field, with the actual product and technology.and setups and issues. I'm not talking about "some" heat but excessive heat, poorly ventilated, etc non-ECC DIMMs.FunBunny2 - Tuesday, October 6, 2020 - link
"That said, why would you want to slow down your memory by getting it colder?"so, I guess, all those billions (if not trillions) we've spent on cryogenic superconduction for computing was boneheaded?
https://www.advancedsciencenews.com/making-faster-...
I want one so I can surf the innterTubes more faster.
Gigaplex - Tuesday, October 6, 2020 - link
Superconductors are very different to semiconductors. That research is irrelevant to semiconductor behaviour.RealBeast - Tuesday, October 6, 2020 - link
Heat is good, huh? So something super-cooled that has no resistance would be quite slow. lolAnd all those fools using liquid nitrogen for speed records are ruining your positive heat theory?
:facepalm:
Tomatotech - Tuesday, October 6, 2020 - link
I personally make my computer go faster by setting it on fire. Half a can of petrol works well, no need to go overboard.Gigaplex - Tuesday, October 6, 2020 - link
Superconductor behaviour is very different to semiconductor behaviour. Superconductors have no resistance and thus no power loss. That's a separate discussion to the actual speed of the electrons in a semiconductor.thetrashcanisfull - Wednesday, October 7, 2020 - link
Who are you, who are so wise in the ways of science?Spunjji - Wednesday, October 7, 2020 - link
So that's where Intel's marginal lead in gaming performance is still coming from! 😂(/s, obviously)
WaltC - Tuesday, October 6, 2020 - link
This looks like something that will take a while coming to consumer-grade products. Might come more quickly to laptops that will capitalize on the power savings, though--but that depends on cost, I should think.Mr Perfect - Tuesday, October 6, 2020 - link
Rumor has it 2021's Alder Lake will support DDR5 for laptop and desktop. Put what stock you will in that.Spunjji - Wednesday, October 7, 2020 - link
Intel do have a long-standing habit of getting consumers to foot some of the early adoption tax for new memory technology. Tiger Lake already has support for LPDDR5, which is rumoured to be hitting products some time early next year - it does at least make sense there due to the potential power of its iGPU (driver issues notwithstanding).TheWereCat - Thursday, October 8, 2020 - link
Ah yes.Z97 will support Broadwell and Z490 is PCIe4 ready.
qlum - Tuesday, October 6, 2020 - link
Looking at these specifications makes me wish there was a higher power variant of the ddr spec. I feel like the continuous push for lower power makes these latencies as high as they are. While I do understand laptops and servers having more benefits from lower power the desktop space generally would not care too much about it and would mostly benefit from lower latency. The difference in latencies between xmp profiles and stock on modern memory are really high. Most memory and memory controllers can handle quite a bit higher voltages than the spec calls for. With these voltages latencies could be reduced and it would be easier to reach higher speeds.Sadly the desktop segment is not the largest so probably not the biggest consideration at least not anymore.
DiHydro - Tuesday, October 6, 2020 - link
I have to point out that 12 Nanoseconds at the speed of light is 3.598 meters (11.8 ft). This seems like a lot when the entire memory trace of a motherboard might be 0.3 m or about a foot. But when you account for clock instability and manufacturing tolerance, we are getting closer and closer to the constraints set by physics. I wouldn't be surprised if that lower floor of ~14ns we see in the specs has more to do with the limitations of the connectors, traces, and motherboard materials than it does with what the chips and memory controllers could do if they were directly soldered together.DanNeely - Tuesday, October 6, 2020 - link
signals in a PCB only travel a bit over half the speed of light. That drops your theoretical number down to about 6.4ft.https://en.wikipedia.org/wiki/Signal_velocity
DiHydro - Tuesday, October 6, 2020 - link
Thanks for the info, that makes me more impressed with the latencies we see on the top end of the enthusiast RAM market. I would love to hear from a memory system engineer to see what they think about being able to go lower latency over higher bandwidth.Tomatotech - Tuesday, October 6, 2020 - link
Many modern system RAM chips are indeed soldered in.Apple was probably the first to do it on high-end laptops, but other companies followed suit. Nowadays the vast majority of fast systems have soldered in RAM chips - iPads, iPhones, Samsung Galaxies, Microsoft Surface Pro, Macbook Air, Macbook Pro, Google Pixels, many high end Chromebooks, the list goes on.
It doesn't seem to have led to any reduction in latency that I know of.
Gigaplex - Tuesday, October 6, 2020 - link
Apparently the latency of HBM2 is roughly comparable to conventional RAM.limitedaccess - Tuesday, October 6, 2020 - link
DIY desktop kits do use higher voltage (1.35V) compared to the JEDEC spec (1.2V) which enables the higher speeds.ats - Tuesday, October 6, 2020 - link
the issue isn't really power but cost. They've made/make variants of DRAM with much lower latencies but the raw cost per GB is almost an order of magnitude higher than with commodity dram. for most of the market, ~10ns array latency hits the sweet spot on cost vs performance.Spunjji - Wednesday, October 7, 2020 - link
You're welcome to goose the voltage yourself in an attempt to try for lower latencies, but you'll find that you rapidly hit diminishing returns.halcyon - Tuesday, October 6, 2020 - link
Interesting. I wonder how long we'll have to wait for lower latencies this time around?Currently one can buy 3200Mhz DDR4 @CL14 (theoretical latency of 8.75ns). This is available as 16GB modules (so up to 64GB on most four slot MBs).
To achieve the same on DDR5, we should get 6400Mhz @CL28.
Revv233 - Tuesday, October 6, 2020 - link
Anyone got some BH5 left sitting around?Still lowest latency memory even today. It took DDR3 to beat it.
eastcoast_pete - Tuesday, October 6, 2020 - link
Not so much a comment on DDR5, but more on memory speeds in general: I am (still) amazed that non-volatile NAND in fast PCIe4 SSDs basically reaches bandwidth numbers of working memory from about 10-15 years ago. IMHO, that's real progress.Now, if AMD and Intel could give us four memory channels for their APUs, we'd be cooking! Even on DDR4 3200, four channels should feed those iGPUs of Renoirs and Tiger Lake a lot better. Hey, I can always ask and dream..
abufrejoval - Tuesday, October 6, 2020 - link
Bandwidth is easy: Just put enough platters of spinning rust in parallel and you can hit 50GB/s.But should you try to run your game on an NVMe instead of DRAM, it won't be a lot of fun because latencies pile up.
Reminds me of fixed head drives or even magnetic drums being used as fast swap devices in the 1960's for DRAM that counted in KWords. But those were running batch jobs where managing locality was hopefully easier.
Spunjji - Wednesday, October 7, 2020 - link
I'm not sure the economics of it works out. Between the larger die area and increase in motherboard complexity, you end up pumping more cost into something that will be beaten senseless by an inexpensive add-in board.The only market in which it makes sense is ones where that board isn't an option - e.g. highly integrated systems - and I don't know that there's a lot of demand for significantly higher GPU performance there (yet).
Tomatotech - Wednesday, October 7, 2020 - link
iPhones, iPads, high-end androids, chromebooks, laptops (Macbooks, Surface Pro, Apple's new ARMbooks), game consoles, VR headsets? There's a lot of demand for highly integrated systems with high RAM / storage / CPU performance.brucethemoose - Tuesday, October 6, 2020 - link
JEDEC went through a lot of trouble to push that much bandwidth over long PCB traces.We've enjoyed discrete memory/logic for a long time, but the traces just have to get shorter. Integrated packages, with memory stacked next to or under the CPU, are the way forward.
Some customers will always need enormous pools, but they can use specialized products. Perhaps they'll start using silicon photonics for memory buses at the very top end.
peevee - Tuesday, October 6, 2020 - link
13nm latency... light IN VACUUM can travel only 39cm in this time, in wires the electrical field is slower. Basically, since DDR3 the latency is limited by physical design of DIMMs separately on the motherboard, with complex routing. And the only improvement can come also from physical design, smaller SO-DIMM slots need to be on the CPU package (say, on the sides) for the shortest possible paths (would also improve energy efficiency due to lower noise in shorter routes).That would also alleviate the need in large LLC.
Corporate Goon - Tuesday, October 6, 2020 - link
You're off by a factor of ten there. Light travels about a foot per nanosecond in a vacuum, so it travels about 390cm in 13 ns.FirstStrike - Tuesday, October 6, 2020 - link
Ian, or any site managers, I plead for removing/collapsing obvious trolls inside the comment area. Otherwise the first few pages is flooded just because a single troll made it to the first.ABR - Wednesday, October 7, 2020 - link
Well if people could restrain themselves from answering them it would be one post.Oxford Guy - Wednesday, October 7, 2020 - link
Exactly.Brane2 - Tuesday, October 6, 2020 - link
What "speeed" ?Just higher revving engine with that "shorter" gearbox, so that the end effect is about the same, only with much more noise...
Gigaplex - Tuesday, October 6, 2020 - link
Not quite. Bandwidth increases with frequency, and that's scaling pretty well. Latency is stagnant. So it's like a more powerful engine giving more top speed, but the 0-60 acceleration times are still the same.Brane2 - Tuesday, October 6, 2020 - link
Marketing "speed" crap aside, they do bring some benefits:- transceivers are tuned for finer geometries which are needed for high capacities
- a bit lower energy useage
- greater bandwith will be great for APUs and perhaps some manycores, like TR x9990 etc.
dicobalt - Tuesday, October 6, 2020 - link
Just a reminder that whenever a new standard of DDR comes out it is the same as the faster older version of DDR. You don't get the true advantages till it has been around a few years and the faster speeds become available. So if you're waiting for DDR5 to build a new PC, don't bother, it's going to be a super long wait.Gigaplex - Tuesday, October 6, 2020 - link
I wonder what moving the voltage regulator onto the RAM module will do for enthusiasts. Will overclockers still be able to adjust the voltage levels? Will there be an industry standard for the BIOS/system to instruct the RAM what voltage it should run at?Spunjji - Wednesday, October 7, 2020 - link
Good question. I'd be amazed if they didn't find a way to make voltage adjustments available to the end-user, but it'll certainly be interesting to see how that's handled.Oxford Guy - Wednesday, October 7, 2020 - link
I anticipate a lot of annoying overpriced tiny fans.AntonErtl - Wednesday, October 7, 2020 - link
The SDR 100MHz latency should be 30ns, not 24ns.The tables with A B C timings and with A timings have three columns for CL, which are always the same; you could squash them to one column. It would be clearer if there were columns for A, B, and C with subcolumns for CL cycles and CL ns. Then you could collapse the A B C lines to one line, and eliminate the separate A table.
Oxford Guy - Wednesday, October 7, 2020 - link
No RDRAM in the chart?kjboughton - Sunday, October 11, 2020 - link
'Everything You Always Wanted To Know About Memory (But Were Afraid To Ask)'That's a dinger of an article. The author really knows his shit.
HarryVoyager - Thursday, October 15, 2020 - link
Dumb question time, but it looks like DDR4 3200 performs identicaly with DDR5 3200, though I do note that the DDR5 spec does go up to higher speeds.What, fundamentally, is being changed between the ram generations? Is it just changes in the way it runs to allow higher effective speeds to be possible?
I think I'm just not seeing why there seems to be so much hype around each ram generation, past DDR.
Great_Scott - Saturday, November 14, 2020 - link
It's good to see that with the new awesome DDR (5), latency will be about where it was since DDR1 ...in 1999.But 20 years for no real improvement isn't bad, it's not like that's been a long time in computer hardware terms.
kotshot - Tuesday, October 19, 2021 - link
why do all the "leaked" DDR5 benchmarks have high Latency like 90+ ns?piotrkundu - Thursday, November 18, 2021 - link
I'm missing something here:DDR3 CL9@1600MHz with 11.25ns latency.
DDR4 CL14@3600MHz with 7.77ns latency.
DDR4 CL15@4000MHz with 7.50ns latency
DDR4 CL16@4400MHz with 7.27ns latency
DDR4 CL18@4600MHz with 7.83ns latency
That is almost half of the 13~14ns mentioned in the article. DDR5 would have double the latency compared to the fastest DDR4. The interesting part with DD5 is the Burst Length (BL16) having 64 bytes prefetch. This could make L2 cache misses less expensive.