Enough Power?

Hello all, and thank you in advance for any help! This is my first time posting on the forums, but I regularly check out the posts and most everybody seems to be helpful.

I have two 8800GTSs in SLI on my ASUS P5N-E SLI mobo and was wondering if my current PSU was strong enough to support them. I am using a 750W Thermaltake Toughpower PSU (http://www.newegg.com/Product/Product.aspx?Item=N82E16817153036).

The reason I am asking is I have been getting some really bad frame rates in WoW (especially in Terrokar Forrest or areas with mass amounts of trees) and I know that two 8800GTSs should never have a problem with this game. If I am looking straight up, I can get over 300FPS (overkill?) but as soon as I run across a zone with tons of trees, the FPS just dump. I am not sure if my cards are getting enough amps from the PSU and if maybe I need to upgrade.

Thank you, again, in advance.

That PSU is plenty. How low are FPS going?

They go from 100+ down to 10-15...Huge hit.

What's the rest of the system made up of? Are you running out of memory or something? Are these G92 GTSs?

I'm sorry, I'm at work and when I built my signature, I didn't realize that it timed out...

Here are my system specs:

ASUS P5N-E SLI MOBO
E6600 @ 3.0GHZ
Zalman 9500
(4x1 GB) OCZ Platinum 800mhz 4-5-4-12
2x DVD-RW
Western Digital Caviar 250GB 7200RPM SATA HD
Thermaltake Toughpower 750watt PSU
640MB 8800GTS x2 SLI (unfortunately not G92s)
Samsung 22" 225BW Monitor

Thank you for such a quick response, btw. After reading my initial post, I left out a ton of information, lol.

I guess I should add that it is not just WoW that seems to kick my computer in the crotch...if I try to play NWN2 on medium settings I get really bad FPS. I am trying to find the bottle neck in my system and upgrade it (would love to build a whole new system, but that will be a while). As far as I know, there should be no reason that I have any troubles in these games. All of my drivers are up to date and the games have the newest patches installed as well. I cannot remember how long it has been happening, but it is irritating and I am looking to fix it.

One of my video cards is the:
http://www.newegg.com/Product/Product.aspx?Item=N82E16814133188

and the second was a gift from my wife and I cannot remember which one it is off the top of my head, but it is new and factory OC'd (though it doesn't matter in my SLI setup).

Something isn't adding up. That system should fly through just about any game at 1680x1050. Can you post up a CPU-Z screen from the mainboard tab, just to make sure the link width is x16 or dual x8, whatever that mobo does in SLI? Are you forcing anything weird through the nvidia driver like extra AA or anything? Defrag the hard drive recently? I know that shouldn't matter for frame rates, but it sometimes does..

As for finding the bottleneck, it really looks like you have a well balanced rig. Something sounds 'off' if you can't even run NWN2 on medium.

I know 3dmark06 isn't worth much performancewise, but giving it a run couldn't hurt - if something is way outta whack, your score will be lower than it should be - I'd guesstimate that system should be getting something like 15k or so depending on clocks?

I am at work atm, so when I get home in a few hours I'll post a screenie. As for 3dmark06, I am only getting a mid 12k.

I defrag reguarly, even killed my antivirus and all that good stuff just to see if that was it. I have not messed with the AA options or anything too much, but I guess I would need to take a look and see what they are set at. I know for NWN2 and WoW there are profiles that get loaded when I play them, but it still seems a bit funky. I am not quite sure. I have run my AV and spyware checks to make sure it wasn't that and nothing came up.

The reason I was wondering if it was the PSU was because if I try to OC my video card even just a little, it will die in the games (BSOD) but I do not get any artifacts or anything. Also, I cannot (even with just 2GB) OC my ram very much...that being said, I was wondering if it was my MOBO. I would not mind upgrading from the 650i series to maybe 780i especially if the 790i knocks the prices down some.

According to the PSU calculator, even with the E6600 at 3.6ghz/1.5v, 100% load, 25% capacitor aging, the system peaks at 645 watts.

Another thing to check: pull out one of the 8800's and see if the frames still stink in those areas..

I know with my PNY, I could not run NWN2 very well at all and then I upgraded to the SLI setup and it still runs about the same. I would figure, if even just an 80% increase, two 640MB 8800GTSs would be overkill for these "old" games over my single GTS.

After reading another post on here, I think I am going to try to completely remove my drivers as well and reinstall them.

I used a few PSU calcs to see what my system would be needing and I got the same as you. The reason I ask about the amps, though, is that I know a single 8800GTS need 26 amps and I have two. My PSU has 4 rails at 18 amps a rail and I am not sure if the rails take away the power that I need. I am pretty confused over it and half of me thinks the PSU is fine and the other half just wants to go spend money, LOL.

Thanks for the quick responses.

When video cards say they require X amps, they really mean the PSU needs that rating to power an entire system plus that card. Until recently, I was powering the system in my sig with a single 450w PSU rated at 18+14 on the 12v rails without an issue. If your dual GTSs were really drawing 26 amps each on their own, you would need a PSU rated for something like 800 watts

Well, if my PSU is not the problem, that's fine with me! Less money to spend LOL. Well, I hope that I can figure it out...this has been bugging me for a while and I have been trying to read up on the forums about anybody else having the same problem, but it seems like most people do not have this kind of problem. I am not sure what is going on if in most of WoW I can get around 200FPS average, but then I hit a few zones and the games just dies on me. I noticed it was happening in areas with a lot of trees, but I remember it falling out on me in other areas, too, so I am not sure. Thanks for helping me to trouble shoot, though!

I know, this is just WAY too obvious, but you're SURE that AA is completely off in the nVidia control panel? Definitely reinstall those drivers by the way. Use DriverCleaner Pro, it gave me an extra 5 FPS in Crysis when I used it to reinstall drivers.

Just curious, I dont want to start another thread. Would I be able to add another 8800gts to the system in my sig, or would I need another power supply first?

Okay, I am back at work and got tied up so I cannot post a screen shot, but my SLI is set to 8x 8x SLI. I did not get a chance to remove one video card and try that but when I get off work in a few hours, it will be my first day off so I can tinker with it a bit.

reclaimer122: I checked the nVidia control panel for anything wierd and I did not see any AA on (I am not using the full control panel where you can set 3D settings, I forgot that I had uninstalled it because it seemed like a piece of garbage. I will check again, though, just to make 100% sure. I will also reinstall the drivers and use DriveCleaner Pro just for the fact that I have updated the drivers a million times trying to figure this out.

It was not a sudden drop in FPS, I just noticed that I did not get the FPS I thought I would in certain parts of the game. Some games are choppy and it does not seem to get any better until I turn everything down. I also play Flight Sim X and that game just destroys my computer and for a while I just assumed the games were too much for my rig.

Diddyu: Ask away! I am getting what I need from everybody, if somebody can help you as well without the thread becoming undreadable, go for it!


Thank you guys for your time and posting your thoughts. I am not new to gaming/computers but I know that it is easy to overlook something such as an AA setting and so all the help I can get until the issue is resolved does not offend me at all.

Well, I was surfing around and I found this on nVidia's website:

http://nvidia.custhelp.com/cgi-bin/...Xh0PTg4MDAgcG93ZXIgdXNhZ2U*&p_li=&p_topview=1

I hope that link will work since it is so long, but it shows that a single 8800GTS requires at least a 400W PSU with 12V current rating of 26A. This is what confuses me and maybe I should post in the PSU section. My PSU has 4 rails at 18A each rail. Does that mean I have 4*18A or just 18A in general? Also, would I require 26A to run both of them, or would it be 2*26A? This is what makes me think I do not have enough juice from my PSU to fully power two 640MB 8800GTSs in SLI.

Of course, when I get home I will check everything else and redo my drivers anyway, but if I upgrade past the 8800GTS in the future, I think I am going to need a new PSU anyway, even if it turns out to be fine with this setup. I am not worried about the wattage but instead the amps, if that makes any sense.

Your fine. It doesn't quite work out to 18A x 4. Each rail is capable of 18A, but not all 4 at the same time. Many PSU's claim multiple rails, and actually only have one, but in either case you have nothing to worry about.

My 8800GT runs on a CoolerMaster Extreme power 500w. Two 12V rails @ 16A and no problems so far.

The 640MB 8800GTS uses more power, though, than the GT right?

Another thing that makes me wonder about the power (though I am still going to check everything) is the fact that my card will not OC at all. I can get the ram up to 900 but that's about it. The stock core is 513 and if I bump it up at all, I can 3dmark06 but no games; the whole system will lock up on me. I do not get any stray graphics of any sort that would make me think I have OC'd too far, it just freezes on me. I can even try this on a cold boot when the temps are low, though they never go above maybe 65.

I read a few reviews on my current PSU and it seems to not be very powerful. I will be a happy camper if I find something else that fixes the problem without having to put ~$400 into a new PSU. I would rather put my money elsewhere in my system.

Now, I am off to remove and re-install drivers. Wish me luck!

I just removed my old nVidia dispaly drivers and used Driver Cleaner Pro.

LOL...it also removed my nForce drivers so I had to get those on a CD and reistall those as well. Glad I had my laptop near by.

Anyway, in WoW, my FPS went to up around 20 FPS in the areas I was having trouble with, so that's a little bit of an increase. I am pleased with that now that I am sitting at ~19-20 FPS in the worste areas of the game.

I also went ahead and pulled on of my cards before removing the drivers and it was a lot worse, so SLI is *working* it seems...