The only potential issue is if you want to load up all we SATA connectors with a bottom-mounted PUS; the distance from the PSU to the first connector is only 45cm (give or take), with a fairly large 12-13cm gap between the connectors, so you'd want the HDD bays to be relatively close to the PSU rather than in the top portion of the case.
First sentence has a few typos. Still reading, but figured I'd point it out.
Gotta say this PSU looks impressive. I'm going to need something soon for my server (not much in the way of cpu and video power, but along the lines of 18-20 HDD's), and something like this might fit the bill. we'll have to see :)
I've been looking for a new high quality PSU for a new build early next year. This looks very promising. Also, Newegg has a $20 mail in rebate and $15 promotional code with free shipping. Thats $135 up front and $115 in the end. That is hard to beat.
"The AX has DC-to-DC for the smaller rails, so +12V feeds +3.3V/+5V and you can't use the whole 62A there."
I know of exactly ZERO XXX-watt power supplies where you can load 3.3V or 5V _in_addition_to_ the XXX watts being consumed on 12V rails.
Actually, most PSU's on the market do not allow anywhere near 99% of its rated load purely via 12V rails like this one. So if anything, such an arrangement should considered a plus.
These days there are lots of PSUs to chose from and the devil seems to be in the details. History has shown that Seasonic can produce good PSUs under their own brand and for other companies but that not all PSUs from them are not equal in design or performance.
Without knowing exactly what the hardware differences are between PSUs and how this impacts performance or reliability makes it challenging when purchasing a new PSU. I watch hardware sites for patterns of issues with specific PSU models and brands when I'm looking for a new PSU.
"Besides, as we pointed out on the noise tests, the hardware required to even push a 750W PSU to the limits is such that you're likely to idle closer to 150W (or higher)."
I am also on the lookout for a high quality build PSU and this point interests me.
Why do these high quality psu always start at around 750W? PSU work most efficient around 50%, as the results in this article also show, so why aren't there any smaller rated ones since idling with it is the most you will be doing?
What about "no-load protection"? When will it kick in on these high end psu?
I probably idle around 120W and wonder if it would be better for the PSU if it has a higher load to work with (relative to its maximum) than almost nothing.
>Why do these high quality psu always start at around 750W?
There are high quality PSU's less than 750W, such as the Seasonic Seasonic SS-560KM 560W. These rarely get reviewed, or submitted for review. Major retailers rarely stock them, especially under 400W. Why? It is a difficult value proposition to get someone to buy a 350-500W power supply for over $100, even though build quality, ripple performance, and hold-up time justify that cost.
The average gamer who just had a 400W cheapie burn out (because it can only produce 200W), then a 800W cheapie burn out (because it could only produce 300W), is finally ready to spend real money for a real power supply. He or She wants 1000W AND quality this time, because clearly 800 (psuedo-)Watts cannot handle a 3.4GHz 920 and single GTX480. But, the gamer cannot afford both Quality and 1000W, so the gamer "takes a chance" with a quality power supply at "only" 750W. Of course, once real quality enters the equation, 600W would be overkill, but that lesson hasn't been learned yet.
>I probably idle around 120W and wonder if it would be better for the PSU if it has a higher load to work with (relative to its maximum) than almost nothing.
The primary difficulty with low-load efficiency is that the 80+ organization doesn't test it, so it doesn't factor into the design because there is no reward for it. The larger a power supply is, the higher wattage the first tier of 80+ testing, since it is percentage based.
A consumer truly concerned with their power bill will purchase a Bronze or Silver with the minimum Wattage rating for their system, rather than a Gold 750 with 400W of excess power. However that is still a difficult value proposition to risk-adverse gamers who have had hardware smoked by the ubiquitous featherweight 400W PSU that came with their first gaming case. For them, excess wattage is insurance.
If I compare with your Enermax review from january (http://www.anandtech.com/show/2920) its seems that one is still the better choice no? (quieter and slightly more efficient)
Hi, well, the Enermax article was written by another editor.
In my opinion Corsair (Seasonic) is better because of very low ripple & noise results, the full modular connection panel and more SATA connectors than the Modu87+ 700W. In addition Corsair is cheaper than Enermax and Seasonic.
Efficiency is not everything, but you are right. Enermax has some advantages too.
Like the very silent fan control (with a separate supplied hall IC).
From the article: It would be nice to see some other brands or types; however, all parts are high-quality. (Trying to use quotes causes errors on post)
Why other brands? Is Nippon Chemi-Con not up to snuff? You claim they are high quality parts. The unit is cheaper than its Seasonic counter part, so I doubt cost is the issue.
Why other types? is there a flaw in this power supplies regulation that would be better served with different parts? Perhaps there is some other undisclosed reason for your comment. (I.E. Brand Preference)
I'm simply confused as to what information I should be taking away from the above comment. Is it a subtle hint that Corsair could have done better, perhaps a poorly worded comment that you often see more variation, or something else entirely?
You mention several times in the article that this is the best Corsair has to offer and I am going to have to disagree......perhaps you meant this family? There is also the AX850 and AX1200.
I personally have an HX850 right now and if I ever find the need to upgrade it will be to an AX1200 for sure. That PSU is a MONSTER in both quality and capability. The fact that the AX1200 is less than a cm longer than my HX850 is also AWESOME considering how big alot of competing 1kW+ PSUs are these days
The AX series as a whole is Corsair's current top-end PSU, yes. We only looked at the smallest entrant in the AX family, but it's reasonable to expect similar quality on the higher capacity models. Still, you'd be pretty hard pressed to fully load 750W, let along 850 or 1200W.
The AX line isn't all made by the same oem. I'd reword the whole this is the best part. You want to see the best, review the AX1200. It's godly. Also worth noting that quality wise the 850HX beats out a few of the AX models still. I think there's 3 oems for both the HX and AX lines so it's a bit complicated.
True there's more than one ODM involved with making the AX series. Seasonic is the ODM for the AX750 and AX850 I believe. The "best" is also up for debate I suppose, but HX850 is 80 Plus Silver and AX is 80 Plus Gold, so in that sense at least it is their "best". Martin is working on a roundup of 1000W+ PSUs, so I'm not sure what's in there but for the uber-PSU folks we have something coming....
All *X series Corsair PSU's are positioned as high-end, versus the -S "gamer" series. The primary difference between AX, TX, and HX is AX is Modular, TX is non-Modular, and HX is semi-Modular.
Of course, there are other differences including OEM and 80+ ratings, especially as some models are older than others. Expect more Gold out of TX and HX lines (or their replacements) as new models supersede old.
Well the AX750 is a great PSU.. I bought it in Germany for 135,- EUR cheapest price on internet... thats 175 US$ - lol.. If I would get them for 115$ - I would buy a second one as spare :D -
Any chance we could get the efficiency and regulation levels in a comparison bar graph like some of the other sections? It would be so much easier to compare the PSU with some of the other units that AT has reviewed in the past!
I have been running a AX750 for about a month now. It is awesome. I have an oscilloscope and have test some basic parmeters. Ripple and voltage is almost identical to Anands. This PSU is a very good deal when you factor in:
1) Gold Cert. Efficiency 2) Nice all black cables, no rainbow colors cables sticking past the sleeve like other power supplies. 3) The $20 rebate that has floating around. 4) The insane 7 year warranty that even Seasonic doesn't offer.
I don't know why some people get all butt hurt when they already own a X-750 or HX850.
Both are great PSU. Almost all PSU from Corsair or Seasonic are winners.
That other guy getting technical that the AX750 is not "the best" compared to the AX1200 is a nut head. AX series is suppose to be Corsairs top of the line series. Tx , Hx, then Ax. Is it better than a HX850? Yes in some areas and no in others.
I think the main reason we don't see more high-quality, high-efficiency PSUs that are lower power is because it's much harder to make a low power PSU that is very efficient at lower loads.
And it's kind of ironic because the 80 plus standard is there to try and encourage efficiency but the standard mandates that the PSU has to be very efficient at 20% load. For a 750W this is a quite reasonable 150W load, but for a 400W PSU this is a very low 80W load. It's ironic because if we could actually buy lower power PSUs they would actually be more efficient for most PC's because most PC's don't need more than 250W-300W max.
I was looking at Newegg's deals on PSU's last Friday, and saw the X750 with the previously mentioned $20 discount at $169.99, but they also had a promo code for an extra $50 off (no longer valid). The Corsair in this review is based on its successor, the X760, as stated.
Researching, it seemed like many people thought the X750 was the best 750W PSU out there. Granted it's about to be succeeded by the X760, but for $120 with promo it was a steal, and I was surprised it didn't sell out at that price. UPS just delivered it and I'll be opening the box next.
Like this reviewer, and another said, 750W should be adequate for even crossfire or SLI rigs, although I wouldn't try to drive 2 GTX 580's with it. I have 3 Seasonics now, including a 330W and my main rig's modular 500W; neither have ever let me down. Also a Silverstone silent 300W I bought a while ago, which I may use again in an HTPC.
Apparently the X750 is silent before reaching a certain power draw, as the Sanyo Denki PWM fan doesn't even spin at low loads. Some people think it is defective for this reason, and one even RMA'd it before realizing his mistake.
I found a handy tool to calculate your PSU requirements here (not sure if links are allowed as it's my first post) but google PUSengine and you'll find it. http://extreme.outervision.com/PSUEngine
I dont know whether the following test is true or not. Most of the website that has tested This AX Gold series PSU shows efficency reaching 93% in some cases and only in one case the efficency drops to below 90% in their AX850. Now i really dont know whether this is the fault of 750 that it is falling below 850model or ur test is wrong. I request u to Please test the AX850 model to get the clear picture overall.. I recently bought this AX750 bcoz saving elec. is my duty towards nature :)
I'm not sure which tests you are talking about, but our measurements are correct. The measured value is relative to the test methodology. It depends, if you use a Chroma, SunMoon or PC; 20°C, 25°C or 50°C; ATX loads or more on the +12V rail and so on.
Even if everyone would use the same chroma with the same temperatures it depends, how many cables there are from the PCB to the testing station. Fox example jonnyguru measured only 89% at 115VAC, while we had more than 90% with the same power grid.
In addition we didn't show every decimal place. The maximum efficiency is a little bit over 91%, so we are very close to other tests.
hi! all of u: i want to know that will it support my system: amd phenom 2 x4 965 be @4ghz 6gb ddr3-1600 mhz kingston ram oc msi -890fxa-gd70 benq g2420hd xfx hd 6970 2gb gddr5 950/1400 will it support my sys.
I have horrible squealing when I have high FPS in games (game menus especially) or other type of GPU load. I believe it is a combination of my PSU and graphics card. I've tried two cards and two psus. GeForce gtx 285 and gtx 470 both squeal much more with a Mist 650W rev 4.0 than the Mist 650W rev 3.5. The only difference is that the rev 4.0 have one 50A 12V rail while the quieter rev 3.5 have four 20A 12V rails.
The mists are known to be squealy I heard, but how about the Corsair AX750 80 Plus Gold? Can you try it with a few recent 3d cards? I'm looking for a quiet psu/gpu combo.
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Chapbass - Tuesday, November 30, 2010 - link
On the cables and connectors page: last para:The only potential issue is if you want to load up all we SATA connectors with a bottom-mounted PUS; the distance from the PSU to the first connector is only 45cm (give or take), with a fairly large 12-13cm gap between the connectors, so you'd want the HDD bays to be relatively close to the PSU rather than in the top portion of the case.
First sentence has a few typos. Still reading, but figured I'd point it out.
Shadowmaster625 - Tuesday, November 30, 2010 - link
Aren't all PUS's bottom mounted?Stuka87 - Tuesday, November 30, 2010 - link
Many newer cases do use a bottom mounted CPU, but it is hardly the only form factor.Stuka87 - Tuesday, November 30, 2010 - link
CPU should be PSU. Wish there was an edit :/Iketh - Wednesday, December 1, 2010 - link
pretty sure they're rear-mounted when bent overNintendesert - Tuesday, November 30, 2010 - link
Last page, first paragraph."Gold requirements. 91% at 50% load is not to shabby."
It should be "too shabby."
Chapbass - Tuesday, November 30, 2010 - link
Gotta say this PSU looks impressive. I'm going to need something soon for my server (not much in the way of cpu and video power, but along the lines of 18-20 HDD's), and something like this might fit the bill. we'll have to see :)props to corsair, another solid unit.
prince34 - Tuesday, November 30, 2010 - link
I've been looking for a new high quality PSU for a new build early next year. This looks very promising. Also, Newegg has a $20 mail in rebate and $15 promotional code with free shipping. Thats $135 up front and $115 in the end. That is hard to beat.mino - Tuesday, November 30, 2010 - link
This left me puzzled though:"The AX has DC-to-DC for the smaller rails, so +12V feeds +3.3V/+5V and you can't use the whole 62A there."
I know of exactly ZERO XXX-watt power supplies where you can load 3.3V or 5V _in_addition_to_ the XXX watts being consumed on 12V rails.
Actually, most PSU's on the market do not allow anywhere near 99% of its rated load purely via 12V rails like this one. So if anything, such an arrangement should considered a plus.
Beenthere - Tuesday, November 30, 2010 - link
These days there are lots of PSUs to chose from and the devil seems to be in the details. History has shown that Seasonic can produce good PSUs under their own brand and for other companies but that not all PSUs from them are not equal in design or performance.Without knowing exactly what the hardware differences are between PSUs and how this impacts performance or reliability makes it challenging when purchasing a new PSU. I watch hardware sites for patterns of issues with specific PSU models and brands when I'm looking for a new PSU.
Nentor - Tuesday, November 30, 2010 - link
"Besides, as we pointed out on the noise tests, the hardware required to even push a 750W PSU to the limits is such that you're likely to idle closer to 150W (or higher)."I am also on the lookout for a high quality build PSU and this point interests me.
Why do these high quality psu always start at around 750W? PSU work most efficient around 50%, as the results in this article also show, so why aren't there any smaller rated ones since idling with it is the most you will be doing?
What about "no-load protection"? When will it kick in on these high end psu?
I probably idle around 120W and wonder if it would be better for the PSU if it has a higher load to work with (relative to its maximum) than almost nothing.
HangFire - Wednesday, December 1, 2010 - link
>Why do these high quality psu always start at around 750W?There are high quality PSU's less than 750W, such as the Seasonic Seasonic SS-560KM 560W. These rarely get reviewed, or submitted for review. Major retailers rarely stock them, especially under 400W. Why? It is a difficult value proposition to get someone to buy a 350-500W power supply for over $100, even though build quality, ripple performance, and hold-up time justify that cost.
The average gamer who just had a 400W cheapie burn out (because it can only produce 200W), then a 800W cheapie burn out (because it could only produce 300W), is finally ready to spend real money for a real power supply. He or She wants 1000W AND quality this time, because clearly 800 (psuedo-)Watts cannot handle a 3.4GHz 920 and single GTX480. But, the gamer cannot afford both Quality and 1000W, so the gamer "takes a chance" with a quality power supply at "only" 750W. Of course, once real quality enters the equation, 600W would be overkill, but that lesson hasn't been learned yet.
>I probably idle around 120W and wonder if it would be better for the PSU if it has a higher load to work with (relative to its maximum) than almost nothing.
The primary difficulty with low-load efficiency is that the 80+ organization doesn't test it, so it doesn't factor into the design because there is no reward for it. The larger a power supply is, the higher wattage the first tier of 80+ testing, since it is percentage based.
A consumer truly concerned with their power bill will purchase a Bronze or Silver with the minimum Wattage rating for their system, rather than a Gold 750 with 400W of excess power. However that is still a difficult value proposition to risk-adverse gamers who have had hardware smoked by the ubiquitous featherweight 400W PSU that came with their first gaming case. For them, excess wattage is insurance.
janwuyts - Tuesday, November 30, 2010 - link
If I compare with your Enermax review from january (http://www.anandtech.com/show/2920) its seems that one is still the better choice no? (quieter and slightly more efficient)Martin Kaffei - Tuesday, November 30, 2010 - link
Hi,well, the Enermax article was written by another editor.
In my opinion Corsair (Seasonic) is better because of very low ripple & noise results, the full modular connection panel and more SATA connectors than the Modu87+ 700W.
In addition Corsair is cheaper than Enermax and Seasonic.
Efficiency is not everything, but you are right. Enermax has some advantages too.
Like the very silent fan control (with a separate supplied hall IC).
JPForums - Tuesday, November 30, 2010 - link
From the article: It would be nice to see some other brands or types; however, all parts are high-quality.(Trying to use quotes causes errors on post)
Why other brands?
Is Nippon Chemi-Con not up to snuff?
You claim they are high quality parts.
The unit is cheaper than its Seasonic counter part, so I doubt cost is the issue.
Why other types?
is there a flaw in this power supplies regulation that would be better served with different parts?
Perhaps there is some other undisclosed reason for your comment. (I.E. Brand Preference)
I'm simply confused as to what information I should be taking away from the above comment.
Is it a subtle hint that Corsair could have done better, perhaps a poorly worded comment that you often see more variation, or something else entirely?
scook9 - Tuesday, November 30, 2010 - link
You mention several times in the article that this is the best Corsair has to offer and I am going to have to disagree......perhaps you meant this family? There is also the AX850 and AX1200.I personally have an HX850 right now and if I ever find the need to upgrade it will be to an AX1200 for sure. That PSU is a MONSTER in both quality and capability. The fact that the AX1200 is less than a cm longer than my HX850 is also AWESOME considering how big alot of competing 1kW+ PSUs are these days
JarredWalton - Tuesday, November 30, 2010 - link
The AX series as a whole is Corsair's current top-end PSU, yes. We only looked at the smallest entrant in the AX family, but it's reasonable to expect similar quality on the higher capacity models. Still, you'd be pretty hard pressed to fully load 750W, let along 850 or 1200W.landerf - Wednesday, December 1, 2010 - link
The AX line isn't all made by the same oem. I'd reword the whole this is the best part. You want to see the best, review the AX1200. It's godly. Also worth noting that quality wise the 850HX beats out a few of the AX models still. I think there's 3 oems for both the HX and AX lines so it's a bit complicated.JarredWalton - Wednesday, December 1, 2010 - link
True there's more than one ODM involved with making the AX series. Seasonic is the ODM for the AX750 and AX850 I believe. The "best" is also up for debate I suppose, but HX850 is 80 Plus Silver and AX is 80 Plus Gold, so in that sense at least it is their "best". Martin is working on a roundup of 1000W+ PSUs, so I'm not sure what's in there but for the uber-PSU folks we have something coming....HangFire - Wednesday, December 1, 2010 - link
All *X series Corsair PSU's are positioned as high-end, versus the -S "gamer" series. The primary difference between AX, TX, and HX is AX is Modular, TX is non-Modular, and HX is semi-Modular.Of course, there are other differences including OEM and 80+ ratings, especially as some models are older than others. Expect more Gold out of TX and HX lines (or their replacements) as new models supersede old.
TheShortOfIt - Tuesday, November 30, 2010 - link
Well the AX750 is a great PSU.. I bought it in Germany for 135,- EUR cheapest price on internet... thats 175 US$ - lol.. If I would get them for 115$ - I would buy a second one as spare :D -iamkyle - Tuesday, November 30, 2010 - link
Any chance we could get the efficiency and regulation levels in a comparison bar graph like some of the other sections? It would be so much easier to compare the PSU with some of the other units that AT has reviewed in the past!King.Koba - Tuesday, November 30, 2010 - link
The best deal for a quality 80 Plus Gold PSU atm is the Seasonic X-750 which is on sale for only $120. http://www.newegg.com/Product/Product.aspx?Item=N8...King.Koba - Tuesday, November 30, 2010 - link
I meant to say X-650*Phoenixlight - Tuesday, November 30, 2010 - link
"A few weeks ago Corsair presented their newest PSUs, the AX series"More like a few months ago...
yati - Tuesday, November 30, 2010 - link
I have been running a AX750 for about a month now. It is awesome. I have an oscilloscope and have test some basic parmeters. Ripple and voltage is almost identical to Anands.This PSU is a very good deal when you factor in:
1) Gold Cert. Efficiency
2) Nice all black cables, no rainbow colors cables sticking past the sleeve like other power supplies.
3) The $20 rebate that has floating around.
4) The insane 7 year warranty that even Seasonic doesn't offer.
I don't know why some people get all butt hurt when they already own a X-750 or HX850.
Both are great PSU. Almost all PSU from Corsair or Seasonic are winners.
That other guy getting technical that the AX750 is not "the best" compared to the AX1200 is a nut head. AX series is suppose to be Corsairs top of the line series. Tx , Hx, then Ax. Is it better than a HX850? Yes in some areas and no in others.
iamezza - Wednesday, December 1, 2010 - link
I think the main reason we don't see more high-quality, high-efficiency PSUs that are lower power is because it's much harder to make a low power PSU that is very efficient at lower loads.And it's kind of ironic because the 80 plus standard is there to try and encourage efficiency but the standard mandates that the PSU has to be very efficient at 20% load. For a 750W this is a quite reasonable 150W load, but for a 400W PSU this is a very low 80W load. It's ironic because if we could actually buy lower power PSUs they would actually be more efficient for most PC's because most PC's don't need more than 250W-300W max.
PeterSF - Wednesday, December 1, 2010 - link
I was looking at Newegg's deals on PSU's last Friday, and saw the X750 with the previously mentioned $20 discount at $169.99, but they also had a promo code for an extra $50 off (no longer valid).The Corsair in this review is based on its successor, the X760, as stated.
Researching, it seemed like many people thought the X750 was the best 750W PSU out there. Granted it's about to be succeeded by the X760, but for $120 with promo it was a steal, and I was surprised it didn't sell out at that price.
UPS just delivered it and I'll be opening the box next.
Like this reviewer, and another said, 750W should be adequate for even crossfire or SLI rigs, although I wouldn't try to drive 2 GTX 580's with it.
I have 3 Seasonics now, including a 330W and my main rig's modular 500W; neither have ever let me down. Also a Silverstone silent 300W I bought a while ago, which I may use again in an HTPC.
Apparently the X750 is silent before reaching a certain power draw, as the Sanyo Denki PWM fan doesn't even spin at low loads. Some people think it is defective for this reason, and one even RMA'd it before realizing his mistake.
I found a handy tool to calculate your PSU requirements here (not sure if links are allowed as it's my first post) but google PUSengine and you'll find it.
http://extreme.outervision.com/PSUEngine
ruzveh - Wednesday, December 1, 2010 - link
To the writer,I dont know whether the following test is true or not. Most of the website that has tested This AX Gold series PSU shows efficency reaching 93% in some cases and only in one case the efficency drops to below 90% in their AX850. Now i really dont know whether this is the fault of 750 that it is falling below 850model or ur test is wrong. I request u to Please test the AX850 model to get the clear picture overall.. I recently bought this AX750 bcoz saving elec. is my duty towards nature :)
Martin Kaffei - Thursday, December 2, 2010 - link
I'm not sure which tests you are talking about, but our measurements are correct. The measured value is relative to the test methodology. It depends, if you use a Chroma, SunMoon or PC; 20°C, 25°C or 50°C; ATX loads or more on the +12V rail and so on.Even if everyone would use the same chroma with the same temperatures it depends, how many cables there are from the PCB to the testing station. Fox example jonnyguru measured only 89% at 115VAC, while we had more than 90% with the same power grid.
In addition we didn't show every decimal place. The maximum efficiency is a little bit over 91%, so we are very close to other tests.
Qbah - Friday, December 3, 2010 - link
And this thing is amazing. The silence is simply incredible! Best PSU there is IMO.akashagarawal3d - Monday, December 20, 2010 - link
hi! all of u: i want to know that will it support my system:amd phenom 2 x4 965 be @4ghz
6gb ddr3-1600 mhz kingston ram oc
msi -890fxa-gd70
benq g2420hd
xfx hd 6970 2gb gddr5 950/1400
will it support my sys.
DarkUltra - Sunday, January 23, 2011 - link
Hi!I have horrible squealing when I have high FPS in games (game menus especially) or other type of GPU load. I believe it is a combination of my PSU and graphics card. I've tried two cards and two psus. GeForce gtx 285 and gtx 470 both squeal much more with a Mist 650W rev 4.0 than the Mist 650W rev 3.5. The only difference is that the rev 4.0 have one 50A 12V rail while the quieter rev 3.5 have four 20A 12V rails.
http://www.bit-tech.net/news/hardware/2009/05/29/m...
The mists are known to be squealy I heard, but how about the Corsair AX750 80 Plus Gold? Can you try it with a few recent 3d cards? I'm looking for a quiet psu/gpu combo.
Nzeman - Wednesday, March 16, 2011 - link
Thanks for the review, great as always. I will be getting this PSU in my new build for sure.