Major GTX280 Review Conflict!

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SystematicDestroyer

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OK among the reviews on the GTX280/GTX260 which are out right now, I found one GIGANTIC discontinuity. It has to do with GTX280 power draw.

In the H Enthusiast review (http://enthusiast.hardocp.com/article.html?art=MTUxOCwxMCwsaGVudGh1c2lhc3Q=):
Should you be thinking about SLI configuring a couple of 280s, I would suggest at least a 700w PSU if you are an overclocker. You could possibly slide by with a very strong 600w PSU, but you would likely be pushing it too hard and would likely be better off with an 800w unit in the long run.
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OK so I'm thinking a nice 750W PSU will be totally fine if you are SLIing 2x GTX260s. Fine.

Then I read the Anandtech review (http://www.anandtech.com/video/showdoc.aspx?i=3334&p=19):
Now remember that a single GTX 280 uses more power than a GeForce 9800 GX2, and thus two of them is going to use a lot of power. It was so much power in fact that our OCZ EliteXStream 1000W power supply wasn't enough. While the SLI system would boot and get into Windows, we couldn't actually complete any benchmarks. All of the power supplies on the GTX 280 SLI certified list are at least 1200W units. ... A 3-way SLI setup using GTX 280s may end up requiring a power supply that can draw more power than most household circuits can provide.
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What the hell? These are two drastically conflicting reports on the GTX280/GTX260s power draw!

What's up? Can anyone demystify?
 
Since Nvidia is being paided by PSU compaines to certify there best PSU's its no surprise they would list the 300-400 dollar 1200+ watt PSU's considering those are big money for these companies. Honestly I'm sure you could run 2x280 GTX's on a decent 750 watt PSU with a solid 60 A total on the 12v rails combined (single 12v rail is still considered the best) with all the usual trimmings in a NORMAL pc that wont overload the current being drawn throughout you're house ..thats just dumb. When computers start requiring 1800-2000 watt 140 Amp draws then yes ..that will be an issue.
 
I guess I would be set if I got a GTX 280 SLI setup (Not that it would be needed cause the PC games are way behind video card technology, except crysis) GTX 280 SLI = epenis in my opinion. Its not that im jealous or anything, but I know when something is a waste of money considering the games out right now or in the near future. All hail the 8800GTX for its longevity!

I have a Silverstone 750w power supply with 4 x 12v @ 18A each = combined 72A.

Im not upgrading until maybe Farcry 2 or something besides Crysis that will need more power for me to run 1680x1050 with 4X AA / 16 AF
 
Supertag said:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139006

that would be the bare minimum I would recommend for a 280 GTX SLI rig. Exactly 60 amps.

I would be comfortable with a little more juice
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This is the PSU I'm thinking about for my system. http://www.newegg.com/Product/Product.aspx?Item=N82E16817703009&Tpk=PC%2bPower%2b%2526%2bCooling%2bS75QB%2bEPS12V%2b750W%2bPower%2bSupply

Now f' the GTX280...simply too expensive. But the GTX260 is a very good card and it's priced more reasonably. I'm thinking about starting with one of these, but I'm getting an SLI motherboard hence I will probably upgrade to 2x GTX260 when the prices come down a bit more or I end up needing a bit more power. Of course, when I upgrade to 2x, I don't want to have to swap the PSU as well.
 
It was generally recommended, even before the anandtech review came out, that 1000w is ideal. But if you get a PSU that can power 2 GX2's then that should be sufficient which there are 850's that do.
 
Nirad9er said:
I have a Silverstone 750w power supply with 4 x 12v @ 18A each = combined 72A.
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Pay closer attention to your label. It'll run ANY of the rails up to 18A, but it does not have 72A combined- probably in the 55-60 range. Simple math shows that 72A * 12V = 864W on the 12V rail alone, and you haven't factored in the other voltages.
 
My Enermax Galaxy 1KW is running my two GTX 280's fine on the sig rig with plenty to spare. My Galaxy should be able to go tri-SLI 280 and still be fine. Anandtech's GTX 280 review looks as though someone didn't stop drinking in time to work.
 
mavalpha said:
Pay closer attention to your label. It'll run ANY of the rails up to 18A, but it does not have 72A combined- probably in the 55-60 range. Simple math shows that 72A * 12V = 864W on the 12V rail alone, and you haven't factored in the other voltages.
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You're right as my 1kW Enermax only has 75A on the 12V rails.
 
We have been able to run a Tri-SLI GTX 280 setup with a 1,250 Watt Cooler Master PSU capably, so I'm not surprised that Anandtech are citing conservative numbers for a PSU. It's also in an enthusiast's best interest to make sure that his PSU is sufficient enough for the task, something that many people unfortunately seem to overlook in many occasions and try to skimp by and get lower-quality or underrated PSUs for their hardware. :(
 
iBP_James said:
We have been able to run a Tri-SLI GTX 280 setup with a 1,250 Watt Cooler Master PSU capably, so I'm not surprised that Anandtech are citing conservative numbers for a PSU. It's also in an enthusiast's best interest to make sure that his PSU is sufficient enough for the task, something that many people unfortunately seem to overlook in many occasions and try to skimp by and get lower-quality or underrated PSUs for their hardware. :(
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While I can understand your point, Anandtech couldn't get a 1kW PSU to power a dual SLI GTX 280 setup and said that the PSU wasn't poweful enough. That's BS. I'm doing just fine with only a 1kW PSU in dual SLI and could probably get it to work in tri-SLI.

In fact if you look at SLIZONE's listed of recomended dual-SLI PSU for the 280, half of them are only 1kW PSU.

Anandtech simply screwed this up, plain and simple.
 
I ran 2 9800gx2's and a q6600 at 3.6ghz on a corsair 750tx with a single 60a 12v rail. And i plan to run SLI gtx280 on it eventually once i can talk myself into spending the 700+ to stepup :)
 
That Galaxy PSU is totally badass...had that specced out for my super rig...similar rig to what you're running, but decided against it due to budget issues...LOL.

Anyways, the problem with a Galaxy is that I can't fit it inside of a ThermalTake Armor! The PSU mounting in that otherwise totally badass case is funky - it mounts sideways. The Galaxy is too big to fit!

So I stepped it down to smaller PSU which has received RAVE marks all it's life...now the question is, could it power 2x GTX260s without problems? I guess it's a whole "What else is in your system thing?"

Going to be running an E8400, 4GB Corsair DDR, 2x WD Raptors, 2x 750GB Seagates, 1x 160GB WD...that's about it.
 
veedubfreak said:
I ran 2 9800gx2's and a q6600 at 3.6ghz on a corsair 750tx with a single 60a 12v rail. And i plan to run SLI gtx280 on it eventually once i can talk myself into spending the 700+ to stepup :)
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This should work but you are going to be pushing it a bit. The cards are going to take close to 40A.
 
SystematicDestroyer said:
That Galaxy PSU is totally badass...had that specced out for my super rig...similar rig to what you're running, but decided against it due to budget issues...LOL.

Anyways, the problem with a Galaxy is that I can't fit it inside of a ThermalTake Armor! The PSU mounting in that otherwise totally badass case is funky - it mounts sideways. The Galaxy is too big to fit!

So I stepped it down to smaller PSU which has received RAVE marks all it's life...now the question is, could it power 2x GTX260s without problems? I guess it's a whole "What else is in your system thing?"

Going to be running an E8400, 4GB Corsair DDR, 2x WD Raptors, 2x 750GB Seagates, 1x 160GB WD...that's about it.
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Yeah, the Galaxy is about the size of one but I actually got it to fit in a retail mini-tower go figure. I do not know why this isn't on nVidia's GTX 280/260 certified list of PSU's as its better than some on that list and its priced well.

So what PSU did you go with?
 
Very interesting catch.

As much as I hate to say it I think the [H] estimate is low. They (at least per the review )did not run an SLI setup/ Just looking at the numbers.

Both the [H] review and Anand and Nvida specs all agree the card can (and did) pull about 250W per card full load. Now here is where I might be going wrong, perhaps in SLI the second card does not draw as much, I honestly dont know. But in specing out a system I would assume the second card draws the same being at best correct and at worst conservative.

So there is 500W for +12.

Both [H] and anand used quads but different ones at different speeds. Now some of the issue mentioned here might not apply but I dont know.

http://www.anandtech.com/weblog/showpost.aspx?i=313

But we must assume the higher number for now so for the cpu all 4 cores at full load at 3.6GHz we guesstimate 275 watts.

Well thats 750w @12V = 62.5A and we need to add the fairly minor loads of motherboard, memory, drives etc.

My personal opinion is that the [H] recommendation for SLI if in a highly OCed quad system is a bit low for my conservative tastes and the OCZ 1000w 80A @12V unit used at Anand is either defective or a POS. I hate big power supplies but in that case I would want 800W+ (and a second mortgage to pay the electric bill).

I predict 10 seconds after posting Kyle will reply that after the review they fired up an OCed quad core SLI 280 rig on a 600W supply with a broken cooling fan and played crysis for 2 days straight.

All of this if from the specs and the reviews. I dont have any of this stuff to play with so this post is worth the electrons used to create it, no more, no less.
 
Look, Anandtech was just wrong or at best misleading, plain and simple. Some of the PSU's certifited for dual SLI GTX 280 are 1kW units. Only the ones that are certified for tri SLI are 1200W and above. And they never even suggested that that had a bad PSU, not to mention the fact that the PSU they did have wasn't on either the 2 or 3 way SLI certified list.

This was just sloppy work by Anandtech and they know it.
 
heatlesssun said:
Look, Anandtech was just wrong or at best misleading, plain and simple. Some of the PSU's certifited for dual SLI GTX 280 are 1kW units. Only the ones that are certified for tri SLI are 1200W and above. And they never even suggested that that had a bad PSU, not to mention the fact that the PSU they did have wasn't on either the 2 or 3 way SLI certified list.

This was just sloppy work by Anandtech and they know it.
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I have to agree with this post. If a 1kw unit weren't enough for it HardOCP's power consumption numbers would be very different than they are in the [H] evaluation. Though the [H] didn't do SLI in this evaluation one can figure out the power usage with some simple math. The Anandtech review is just plain wrong on the power usage.
 
this is hinky. i have been running quad sli for months now with a maybe-slightly-above-average 650watt psu. 1200 watts for 280 sli is bullshit.
you guys know that to get sli certified you just need a check for i think its $20,000? so of course if you are selling psu's, you are going to buy sli cert for your most expensive power supplies. doesnt have much, if anything to do with capacities of the psu's.
 
Why aren't 200w PSU's listed as SLI certified for the GTX 280 then? Just saying dude.
 
Godmachine said:
Since Nvidia is being paided by PSU compaines to certify there best PSU's its no surprise they would list the 300-400 dollar 1200+ watt PSU's considering those are big money for these companies. Honestly I'm sure you could run 2x280 GTX's on a decent 750 watt PSU with a solid 60 A total on the 12v rails combined (single 12v rail is still considered the best) with all the usual trimmings in a NORMAL pc that wont overload the current being drawn throughout you're house ..thats just dumb. When computers start requiring 1800-2000 watt 140 Amp draws then yes ..that will be an issue.
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The corsair TX 750W will take two GTX280s on Skulltrail w/ a raid 10 config. You can quote me.

a 750W source running for 1 min is enough to get a 1.5 ton car moving at 25 miles per hour. (750 x 60)(.9) = (.5)(1500 x .453)(V[in m/s]^2) These days consumer grade PSUs really do have quite a lot of power.

edit: har har, on the point of tripping circuit breakers, a 750W PSU is going to pull maybe 8A from the wall, so I think your OK.
 
MrWizard6600 said:
The corsair TX 750W will take two GTX280s on Skulltrail w/ a raid 10 config. You can quote me.

a 750W source running for 1 min is enough to get a 1.5 ton car moving at 25 miles per hour. (750 x 60)(.9) = (.5)(1500 x .453)(V[in m/s]^2) These days consumer grade PSUs really do have quite a lot of power.

edit: har har, on the point of tripping circuit breakers, a 750W PSU is going to pull maybe 8A from the wall, so I think your OK.
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Not that I am disputing you in any way, I just thought that MrWizard bustin out the electrical knowledge was funny as hell :p
 
PSUs don't get certified to be on the SLI list overnight. I remember it took awhile for the Silencer 750 to get certified for 8800GTX SLI by Nvidia.

As time goes on, we will see more psu's on Nvidia's SLI list for the 280.
 
I was shocked to see that the hx1000 was not listed for 280 sli right off the bat considering the punch it packs.
 
The biggest issue here is the difference in stability between a good PSU and a bad one. Back in the day I had a cheap 500W PSU die in a pretty average system but a 350W Antec PSU handled the same system just fine (this is way back when 500W was a LOT)

I was looking at the 850W Antec Quattro for possible future SLI x2 configs, I'd certianly expect a decent make of PSU like theirs to happily feed 2x GTX 280's with a fairly standard system, if you had OC'd quad cores and 4 HHD's in RAID 0 and a whole bunch of kit then I'd probably stretch to a Antec 1KW Quattro.

I have no personal experience with SLI specifically but I do have many years of experience seeing the 150%-200% difference in actual stable power output delta between an equally rated good and bad brand of PSU.
 
Hehe, sounds like Anand needs to send that PSU to Kyle and let him put it through its paces to make sure it's functioning properly.
 
If you look at some of the power measurements, the 280 actually draws a little over 200W peak - by itself. It was using ~160W more than a 9600GT. If you do the math, that's closer to 220W peak. So 2 x GTX means ~440W peak, to be safe.

The tricky part is that is dedicated 12V rails power, not total draw across all three voltages.You're also using 12V power for other things. A 60A rating should do if the PSU has a single 12v rail. With a 50A rating you're cutting it close, depending on what else you have running, such as fans or other active cooling, drives, lights etc. Specially iff you have multiple rails, some rails are limited to 18-20A on < 1000W PSUs, and this is what could make even a 1000W trip, if it has 4 independent 12V rails and if they are not all rated at > 20A draw, and you have the GTX 280 plus a couple of fans or drives hooked up to the same rail, you will go over the 20A draw.

Its cases like this where 1 big 12v rail is more useful than lots of lesser rails.
 
The 750TX is a SINGLE rail psu. Thats why i love it so much. 60A on 1 rail. No math involved :p
 
Alright, according to most of people here, the 750 Quad Silencer from PC Power & Cooling should be fine for a pair of GTX260s. Done a few calculators that say it'll be clean for it anyways, based on 9800GX2 and the power draw of a GTX260 is supposedly lower than the 9800GX2 anyways.
 
vanilla_guerilla said:
as soon as they send their check to nvidia, they will be certified.
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true, I saw ram that was SLI certified, wtf does ram have to do with sli? I guess when someones shopping online and they're buying a sli system, and they see a pair of ram that's sli certified, they will pick that over one without the certification. It's a great marketing strategy by nvidia.
 
Kelv said:
true, I saw ram that was SLI certified, wtf does ram have to do with sli? I guess when someones shopping online and they're buying a sli system, and they see a pair of ram that's sli certified, they will pick that over one without the certification. It's a great marketing strategy by nvidia.
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SLI certified RAM has support for EPP (Extreme Performance Profiles) which contain different settings that SLI ready boards can read and configure the memory from which are more aggressive than the JEDEC specs normally read from the memory modules' SPD tables. I have some OCZ Flex XLC modules rated for 1150MHz. On a non-SLI ready motherboard the modules get setup as 800MHz modules with timings I can't remember. When installed in an SLI capable motherboard that supports the EPP feature (higher end SLI boards only) then it sets the memory to run at 1143MHz with different timings.

Timings, clock speeds and voltage values are all different between the memory's SPD and EPP tables.
 
I feel "old school" here.

I have a Triple Sli comp running three 8800 GTXs and an overclocked Q6600 plus a bunch of watercooling......

I use an Ultra X3 1000W and it's cool as a cucumber......single 12V rail with 70A (which at this point seems whimpy) and never breaks a sweat.

To the Galaxy guy.....check out the Ultra, it may be small enough to fit in the Armor case.
 
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