Yeah, the writing is on the wall for DDR5 DIMM. It's slow, power hungry, and can't even hit these speeds. Desktops should switch over to CAMM or SODIMM that can be attached closer to the CPU.
Actually, SODIMM is confirmed dead after this generation in favor of CAMM, and DIMMs will be around for at least another generation. DDR5-12600 DIMMs are possible.
I'm fine with DDR5 SODIMM being canned. It runs too hot with a stacked layout. Desktop DIMM should go straight to CAMM as well. DDR5-12600MT/s is what? 8400? Is it the Triden Z5 with 40-52-52-134 at 1.4V? Disgusting
Where would you put CAMMs on a desktop board? They're a lie flat design optimized for thinness, meaning they take a lot more space than DDR slots; and we've already covered all the available space on mobos with m.2 slots.
This. Using the front and back of a motherboard doubles the number of CAMM connectors. Just using two sides of a CPU permits four connectors and a 512 bit wide aggregate memory interface. That is workstation class performance there. Might be able to use a third side of a CLU to get two more connectors front back for a 768 bit interface. That’s Epyc server territory right there. That is over 900 GByte/s of bandwidth if the 9.6 GT speed can be maintained.
Lots of people complain about the soldered down ram in Apple products or thin and light laptops asking for exactly the opposite. Socketed so it can be upgraded later in life or just to avoid the premium of buying the memory from the OEM. LPCAMM might be able to mostly give use the best of both worlds. LPDDRx speed and power advantages but still user up-gradable.
I think soldered RAM is less of a problem now than it was in the past. Almost out of the box, PCs needed a RAM upgrade just to be usable about 20 years ago. Now, though 8GB is a bit of a pinch for some people, mundane workloads like poking around the web, communicating, crunching a spreadsheet and whatnot are all not in dire straits and 8GB has been kind of a standard experience since Ivy Bridge was a thing a decade ago. Yeah I wouldn't buy a NEW PC with only 8GB, but the laptops my office supplies to employees and purchased in 2021 had 8GB. They work okay. 16 would have been better for longevity, but life cycle replacement is coming in about a year so no one cares enough to do anything about it even though they have a single memory stick and could be easily upgraded. At this point, I'd argue that soldered RAM is good enough if it saves costs, power, and leaves a little more internal volume for battery or an extra USB port.
The 4 and 2 GB computers of the past were described the same way you describe 8GB now. Surprisingly, they were not actually, fine, they were slow AF.
8GB now is nearly unusable. They dont work fine for any serious office work where you have more then 1 spreadsheet open. Especially once you have all the corporate monitoring tools, antivirus, management software, ece installed.
Indeed. Upon boot the OS consumes nearly half of that 8 GB figure which leave 4 GB for applications. That should be plenty for basic tasks but abominations like MS Teams can consume 5 GB on their own (I personally seen this. It was repeatable for awhile.). At this point things are hitting the slow swap file and performance crashes.
8 GB can be useful today but it’d require software developers to get their act together and rewrite code to be lean and efficient again. Inefficient but works is what they’ll produces until consumer outrage becomes too much or vendors just make 16 GB standard.
Although RAM BW hasn't been able to keep up with compute performance, that doesn't mean that soldering DRAM down will alleviate the problem. If anything, we could try and have more channels if we want more BW from our RAM.
If we tried the soldered down approach, then MBs would have to be much bigger and the manufacturers of MBs would have to produce many more models leading to a huge increase in cost. What's more, when your RAM goes bad, you'd have to replace the whole MB.
The RAM could be packaged on the CPU like Apple's M series, and the CPU could still be socketed. This would *decrease* the cost of the motherboard too, as it no longer has to run all those RAM traces.
Exactly, so why bother? The more caches you have the less relevant memory performance is so the cheaper, expendable, replaceable DIMMs is a no brainer.
And as for bandwith, some workloads (like llama.cpp CPU offloading) are essentially RAM speed bound. I would *love* for my 7800 to be quad channel instead of dual.
Even finding latency information for LPDDR is difficult, but I did see some once for LPDDR5-6400 which had a latency which equated to about CL80 in DDR5 terms. If you increase the speed by 50% and further reduce power in LPDDR5T-9600 that's going to increase the latency by at least 50% and probably more so you're talking CL120+
HW utilities should show timings in LPDDR5X laptops.
Also, some DIMMs and SODIMMs run at really awful timings for seemingly no good reason. My two CL48 6000 sticks can drop from CL48 to CL36 (maybe less) at the stock 1.1v, which seems like an excessive amount of factory headroom.
Oh and I should note that the controllers introduce significantly more latency than DDR5 controllers, because they are driving signals at lower power - they don't have to but LPDDR controllers are designed with lower power so unless someone built a new one from scratch that doesn't try to save power it will introduce additional latency.
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brucethemoose - Wednesday, October 25, 2023 - link
Can we get some of this on desktops, please?I'm ready to trade away DIMMs for packaged RAM if we get speeds/voltages like this.
meacupla - Wednesday, October 25, 2023 - link
Yeah, the writing is on the wall for DDR5 DIMM. It's slow, power hungry, and can't even hit these speeds. Desktops should switch over to CAMM or SODIMM that can be attached closer to the CPU.nandnandnand - Wednesday, October 25, 2023 - link
Actually, SODIMM is confirmed dead after this generation in favor of CAMM, and DIMMs will be around for at least another generation. DDR5-12600 DIMMs are possible.meacupla - Thursday, October 26, 2023 - link
I'm fine with DDR5 SODIMM being canned. It runs too hot with a stacked layout.Desktop DIMM should go straight to CAMM as well.
DDR5-12600MT/s is what? 8400? Is it the Triden Z5 with 40-52-52-134 at 1.4V?
Disgusting
DanNeely - Monday, October 30, 2023 - link
Where would you put CAMMs on a desktop board? They're a lie flat design optimized for thinness, meaning they take a lot more space than DDR slots; and we've already covered all the available space on mobos with m.2 slots.meacupla - Tuesday, October 31, 2023 - link
You put it in under the CPU keep out zone, obviously.Have you seen how much room 4x DDR5 DIMM slots and its traces take up?
Since it's flat, I'm sure it can even be mounted to the rear of the mobo. Not that I think that's necessary, unless it's mITX.
Kevin G - Tuesday, October 31, 2023 - link
This. Using the front and back of a motherboard doubles the number of CAMM connectors. Just using two sides of a CPU permits four connectors and a 512 bit wide aggregate memory interface. That is workstation class performance there. Might be able to use a third side of a CLU to get two more connectors front back for a 768 bit interface. That’s Epyc server territory right there. That is over 900 GByte/s of bandwidth if the 9.6 GT speed can be maintained.kpb321 - Wednesday, October 25, 2023 - link
Lots of people complain about the soldered down ram in Apple products or thin and light laptops asking for exactly the opposite. Socketed so it can be upgraded later in life or just to avoid the premium of buying the memory from the OEM. LPCAMM might be able to mostly give use the best of both worlds. LPDDRx speed and power advantages but still user up-gradable.PeachNCream - Wednesday, October 25, 2023 - link
I think soldered RAM is less of a problem now than it was in the past. Almost out of the box, PCs needed a RAM upgrade just to be usable about 20 years ago. Now, though 8GB is a bit of a pinch for some people, mundane workloads like poking around the web, communicating, crunching a spreadsheet and whatnot are all not in dire straits and 8GB has been kind of a standard experience since Ivy Bridge was a thing a decade ago. Yeah I wouldn't buy a NEW PC with only 8GB, but the laptops my office supplies to employees and purchased in 2021 had 8GB. They work okay. 16 would have been better for longevity, but life cycle replacement is coming in about a year so no one cares enough to do anything about it even though they have a single memory stick and could be easily upgraded. At this point, I'd argue that soldered RAM is good enough if it saves costs, power, and leaves a little more internal volume for battery or an extra USB port.TheinsanegamerN - Monday, October 30, 2023 - link
The 4 and 2 GB computers of the past were described the same way you describe 8GB now. Surprisingly, they were not actually, fine, they were slow AF.8GB now is nearly unusable. They dont work fine for any serious office work where you have more then 1 spreadsheet open. Especially once you have all the corporate monitoring tools, antivirus, management software, ece installed.
Kevin G - Tuesday, October 31, 2023 - link
Indeed. Upon boot the OS consumes nearly half of that 8 GB figure which leave 4 GB for applications. That should be plenty for basic tasks but abominations like MS Teams can consume 5 GB on their own (I personally seen this. It was repeatable for awhile.). At this point things are hitting the slow swap file and performance crashes.8 GB can be useful today but it’d require software developers to get their act together and rewrite code to be lean and efficient again. Inefficient but works is what they’ll produces until consumer outrage becomes too much or vendors just make 16 GB standard.
ballsystemlord - Thursday, October 26, 2023 - link
Although RAM BW hasn't been able to keep up with compute performance, that doesn't mean that soldering DRAM down will alleviate the problem. If anything, we could try and have more channels if we want more BW from our RAM.If we tried the soldered down approach, then MBs would have to be much bigger and the manufacturers of MBs would have to produce many more models leading to a huge increase in cost. What's more, when your RAM goes bad, you'd have to replace the whole MB.
So personally, I'll stick to socketed RAM.
brucethemoose - Thursday, October 26, 2023 - link
More channels also means much more cost.The RAM could be packaged on the CPU like Apple's M series, and the CPU could still be socketed. This would *decrease* the cost of the motherboard too, as it no longer has to run all those RAM traces.
TheinsanegamerN - Monday, October 30, 2023 - link
Exactly. Keep CAMM around, we dont want everything soldered and disposable.Doug_S - Wednesday, October 25, 2023 - link
You're sacrificing latency for low power and bandwidth by using LPDDR5 instead of DIMMs.Samus - Wednesday, October 25, 2023 - link
With the size of modern CPU caches, RAM latency is becoming less and less important.ian9298 - Wednesday, October 25, 2023 - link
Exactly, so why bother?The more caches you have the less relevant memory performance is so the cheaper, expendable, replaceable DIMMs is a no brainer.
brucethemoose - Thursday, October 26, 2023 - link
And as for bandwith, some workloads (like llama.cpp CPU offloading) are essentially RAM speed bound. I would *love* for my 7800 to be quad channel instead of dual.brucethemoose - Thursday, October 26, 2023 - link
This is not always true. I have a 7800X3D, and I got a noticable bump in some sim games running CS30 vs the default CS48.brucethemoose - Thursday, October 26, 2023 - link
Are their timings that bad? I don't see why that has to be the case when the traces are shorter and better.Surely they can be factory overclocked a bit for desktop CPUs.
Doug_S - Thursday, October 26, 2023 - link
Even finding latency information for LPDDR is difficult, but I did see some once for LPDDR5-6400 which had a latency which equated to about CL80 in DDR5 terms. If you increase the speed by 50% and further reduce power in LPDDR5T-9600 that's going to increase the latency by at least 50% and probably more so you're talking CL120+brucethemoose - Thursday, October 26, 2023 - link
Interesting.HW utilities should show timings in LPDDR5X laptops.
Also, some DIMMs and SODIMMs run at really awful timings for seemingly no good reason. My two CL48 6000 sticks can drop from CL48 to CL36 (maybe less) at the stock 1.1v, which seems like an excessive amount of factory headroom.
Doug_S - Thursday, October 26, 2023 - link
Oh and I should note that the controllers introduce significantly more latency than DDR5 controllers, because they are driving signals at lower power - they don't have to but LPDDR controllers are designed with lower power so unless someone built a new one from scratch that doesn't try to save power it will introduce additional latency.