Thrmaltake 680 watt PSU inadequate for SLI

[David M]

I purchased one for the below system. Although Thermaltake advertised that it would work for my system it was not adequate. The 12 volt rails run at 11.8 volts give or take a few 10's and with a load on the rails the rails running my two 6800 Ultra cards dropped below 11.5 volts. Thermaltake provides one 12 volt rail that is supposed to drive both graphics cards. The reality is that each card draws about 90 watts and your supposed to draw 180 watts from one rail?...no way. I had to to run one rail to each card which is what the manufacturers of the cards require. I don't know what Thermaltake was thinking running two 6800 Ultra cards with one 12V rail.

I kept having screen freezes, artifacts and PSU shutdowns. I purchased a 850 watt PSU from PC Power and Cooling which eliminated my graphics problems. My new PSU has a rock steady 12.2 volts under all loads.

There are only 4 PSU's that nVidia recommends and the Thermaltake 680 is not on the list. http://www.xoxide.com/slicertified.html

The moral of the story is to stick to PSU's that are certified by nVidia for SLI use if you want to avoid undervoltage problems.

[mb26]

*wow*, u actually spent (around) $500 on your PSU?
thats more than my entire computer.

personally i would take a different moral; dont expect a PSU to be good just because it has '680w' stuck on it, and dont expect anything exceptional from thermaltake.

i would have thought, in the worst case scenario, using dual PSUs would have been far more cost effective and maybe even, better.

but clearly money is not so much of an issue for you so maybe it was worth it :)

[David M]

I got shafted byThermaltake the first time. For me it was worth paying extra so I did not get shafted a second time. It's not worth my time buying and returning and guessing which PSU is going to work in order to save a little money. So I bought a PSU I knew was going to work for sure...and it works wonderfully :)

I was not interested in trying to cram dual PSU's inside my case nor in hanging one off the side of my case.

If I wanted an ugly case I would have bought a Thermaltake case and hung watercooling junk and a second PSU off the side....LOL :)

[Marke522]

What about the Enermax? That's the one I used on my A8N build last month. I thought THAT one was too much money, but it seems to work so far. We didn't run it in SLI mode yet. Ran out of money. :) It's on the list so I wasn't worried about making sure it was enough power.

[David M]

Do you mean this Enermax? http://www.xoxide.com/enermax-600w-eg701ax-sfma2-sli.html

Yes, I considered it because it was one of four that is certified by Nvidia but I decided not to purchase it because of its wattage...600 watts versus the Koolances 680 watts (as they claim). I hate having to return things so I went with something I knew for sure would work...even though it was expensive. Call me impatient, but I did not want to wait a week for a PSU that might work versus waiting a week for one that will work.

Which PSU did you end up purchasing? I am running two 6800 ultras in SLI and they really suck down the watts. In fact at first they were overheating with the case door off. The GPU's were running over 70C at times and shutting thenselves down...yikes!..even with the case door off. When I watercooled the GPU and the chipset the GPU temp dropped down to reasonable temps.

Woops... I just read the the forum guidelines and forgot to rate the Thermaltake 680

Given it did not work at all for what Thermaltake claims it is supposed to do I give it a failing grade. Would this be a zero out of 10?

Rating: Zero out of ten.

[Marke522]

Do you mean this Enermax? http://www.xoxide.com/enermax-600w-...-sfma2-sli.htmlYeah that's the one. I used this calculator here http://www.jscustompcs.com/power_supply/ and it said all I needed was about 400, so I wasn't worried about the Enermax being enough.

But I completly understand what you mean about paying more for the peace of mind. Just to be completly sure that it would work rather than guessing and hoping you're right. Somtimes that's well worth the extra cost.

[David M]

I know we are not supposed to be rambling in this forum but hopefully others will gain valuable info concerning PSU's for SLI systems from our ramblings. Looks like you got yourself a great PSU for your system but if you want to upgrade to SLI with 6800 ultras you may want to look at the Enermax 600. In retrospect, I probably spent too much. Others may be better off with the Enermax 600 since it is substantially less expensive than the 850. This of course has me curious if the Enermax 600 will actually run two 6800 Ultras.

[Marke522]

I'll have to let you know, should be a few months. There will be a little extra cash once classes are over.

I'll let you know as soon as I find out. I've been on these boards for awhile and not planning on going anywhere else.

[Unrealwarrior]

My rating 1 out of 10 it looked nice in the box. I too feel your frustration. I built a very high end system and thought surely the 680 watt PSU advertised would easily fill the bill. However I was quickly dissapointed. Trying to run demanding games like DOOM 3 / FAR CRY / HL2 / Splinter Cell Chaos Theory my system would hard crash in less than 5 minutes every time. I RMA'ed the PSU got one returned fairly quickly and was even further dissapointed when The PSU I received was all scratched up on the black finish. Anyway I installed it and whamo same problems. MY 12 volt rails have dropped to 10.8 before it crashes. I swapped out the Thermaltake PSU with a 3 year old PC Power and Cooling 510 Deluxe Power Supply and everything worked great. My system acheived a 3D 2005 Mark score of 10,075. The games run for hours on end at maxed out settings although the PC does get warm being air cooled but (3) 120mm fans do the trick (Chenbro Gaming Bomb II Case). Here are my system specs:Asus A8N-SLI DLX / AMD 64 4000+ / 2GB Corsair DDDr 400 2-2-2-5 / (2) BFG 6800 Ultra OC's 256MB / Audigy 2 ZS Platinum / (2) WD Raptors 74GB RAID 0 SATA / Maxtor 300 GB SATA II / WD 120 GB SATA / NEC 3520 DVD DL burner.

BE WARNED of BS Advertising :mad: :mad: :mad: :mad:

[David M]

Unreal,
Yet another fine reason to check out PC Mechanic before buying. You have a really nice system!

[chzlchp]

Ya know, there's an old saying that goes, "Poor people always buy twice".

Alternately, you spend good money on a good product, and the bite of the cash is soon replaced (and forgotten) by the satisfaction gained when what you have works and works well, and keeps on doing so.

[maynoth]

Man just get one of those OCZ power supplies with the adjustable rails... you can tweak the rails back to normal even if they are off...

[mb26]

"I was not interested in trying to cram dual PSU's inside my case nor in hanging one off the side of my case." yea, there are cases which support 2 PSUs i meant :)

i think the enermax 600w is probably the way to go for SLI..

remember kiddies, its not about the big number stuck on it! its the quality :p

[David M]

Here is a link to Nvidia certified PSU's. I would not consider anything else to power an SLI system.

http://www.slizone.com/object/slizone_build.html

[TastyHiHatWork]

Why the Enermax 600 over the Silverstone 650?

[maynoth]

uhhhhh Why not just get an OCZ with adjustable voltages... then you can tweak using a multimeter.... I have one they are frigging awesome...

[rustywood]

i also built a high end pc with a 6800gt vc .matter of fact i went through 4 of them in 3 months!!first 3 it WAS the vc the 4 had a little problem till i found out after a bunch of trouble ,trips to pc repair, going throug RMA hell,that the brand new thermaltake 480w pu was way underated for the vc and was crapping out,sooooooo i tossed it,bought a OCZ520 with the ajust rails and havnt looked back. my pc has worked flawlessly since. this power unit can handle anything,just as good as a pc&c unit!

[glc]

Here is a link to Nvidia certified PSU's. I would not consider anything else to power an SLI system.

http://www.slizone.com/object/slizone_build.html

Ditto. There's a reason for the certification program. I won't recommend an OCZ for SLI until it's certified.

[tterrag46]

Personally, I would have used the Seasonic. It's extremely quiet and efficient.

[enhanced08]

i too had a problem with a tk PSU, it was a 420watt and was no where near powerful enough for my system! i had to un plug fans/lights and even unhook my 200GB back up drive just to keep it from restarting!

i had always heard great stuff from thermaltake but i wont buy a PSU from them again!

[storrisch]

in case anyone is wondering about the silverstone psu on the nvidia website i have one and have yet to have any issues. my 12v rail usually sits right at 11.84. and have more than enough power for my {currently solo} 7800gtx

[Daggerfall_Addict]

you cannot beat adjustable rails.... if the rails are off under a full load you can adjust to compensate.... best thing since sliced bread

[Ishy]

Ditto. There's a reason for the certification program. I won't recommend an OCZ for SLI until it's certified.
anandtech used the 520 for testing SLi systems, the only reason its not SLi certified is because ocz don't wont to pay to have nvidia say "yep that'll run an SLi system, here have a badge". ;)