Asus 7900GTX SLI problems

[exttesi]

I am having an issue with my SLI ASUS 7900GTX configuration. Most of the time when I play 3D games or do any benchmarking, monitor would loose signal and the only way to get it back is to restart the PC. Anyone else is having similar issues or have a solution for this? I tried using just one video card and it appears that both of those cards function just fine, but in SLI mode it?s a no go ?

Please post any suggestions of info

Thank you

 

[CKXP]

PSU maybe? what kind do you have?

edit: please list the rest of your system specs.

 

[exttesi]

bah dont remember the brand, got it from CampUSA, it's a 700watts monster

 

[nitromullet]

Well, that is actually pretty important. Pop open the case, take a look, and let us know (brand and model).

Welcome to AT forums

edit: ...and the rest of the system specs might help also...

 

[Crescent13]

Originally posted by: exttesi
bah dont remember the brand, got it from CampUSA, it's a 700watts monster

that could be your problem. You may have bought a generic PSU, AKA Crap. I'd bet that 700Watt "monster" could get it's ass kicked by the 510W PCP&C PSU.

Brand is very important.

EDIT: Please list all of your specs.

 

[exttesi]

will do, going to be home in an hour or so and will post all the info. Thank you guys for responding

 

[exttesi]

Motherboard: Asus M2N32-SLI Deluxe

CPU: Athlon 64 X2 5000+ (AM2) 2.6 Ghz , Dual Core, L1: 128KB x2

HD (RAID 0): 2 Western Digital Raptor WD740ADFD 74GB 10,000 RPM 16MB
Cache Serial ATA150 Hard Drive - OEM

RAM: Patriot PDC22G6400LLK Memory Patriot 4GB (4 x 1GB) 240-Pin DDR2
SDRAM Dual Channel Kit System Memory

Video Card (2 SLI): VGA ASUS EN7900GTX/2DHTV/512M

Vortec 700W Power Supply


here is what i got, going to put this in sig also

 

[CKXP]

i couldn't find much info on your PSU except that it's manufactured by MGE, is there a way that you can look on the side of your PSU and see what the amps are one the 12v+ rails there should be two since it's a 12v dual rail power supply.

this could be the source of your problem, there a few articles where high-end SLI or Crossfire setups might run into problems using dual rail PSU's

http://www.extremetech.com/article2/0,1558,1932947,00.asp

the article is kind of old and uses two 7800gtx's 512mb as reference which btw will draw more power than your two 7900gtx's, but you should get the idea way a Brand name PSU is so important.

 

[Ackmed]

Does it do it with SLI disabled? Have latest drivers? If so, perhaps a reinstall. Got chipset drivers? Could be various things. If I recall, SLI will give you a pop-up box telling you there isnt enough power.

 

[exttesi]

http://www.compusa.com/products/product...ortec+700W+Power+Supply&cm_cat=1581857

is what i got.

would you guys recommend me switchign to BFG Technologies PC System 650 Watt ATX 12V Power Supply?

http://www.compusa.com/products/product...C_System_650_Watt_ATX_12V_Power_Supply

i just resently got it so i can exchange it to BFG PSU

 

[moonboy403]

try seasonic s12 600w

that's what i used for my 7900 gtx sli setup

 

[TheRyuu]

Originally posted by: moonboy403
try seasonic s12 600w

that's what i used for my 7900 gtx sli setup

I got that one too. It's quiet as hell. Aparently the fan only spins at 700rpm (according to my mobo). Not sure if it's suppose to spin that slow but it's quiet.

(and I also have a 7900GT SLI setup vmodded to turn into 7900GTX setup )

 

[Gstanfor]

If you have the case space, just jumper the power good pin of your old PSU to ground, then use it to power the cards. Its what I did and far less hassle than mucking around with monstrous power supplies, dual rails and all the rest. Of course as I mentioned you'll need a case with space for a second PSU (love my cooler master stackers).

 

[exttesi]

after reading the article posted by CKXP, looks like this is not the problem that i am having, what they experiansing is computer frezes or shutsdown, my problem is that monitor just looses signal but PC still runs. All the drivers i have are up to date, and i tested each card seporatley and it looks like both of them are working just fine. As far as getting a new PSU, well i only have 2 choice, keep the one i have or exchange it to BFG
http://www.compusa.com/products/product...C_System_650_Watt_ATX_12V_Power_Supply

i dont really have money to spend on anythign else now. Anyone knows if BFG PSU better in any way than what i have?

 

[exttesi]

ok i found that this problem is not just with me, and it was not the PSU
here a bit from another forum


"magnumJun 25 2006, 03:25 PM
For some reason my monitor loses signal now I have upgaraded to 7900gtx sli. The cards are not running hot amd have both been checked over and are fine. Is there anything in the bios that can be causing this. In device manager I have 2 monitors in the monitor tab both my viewsonic e92f+, is this normal as I have sli? I have disabled legacy usb as someone on a forum said it may help but if anyone has had this expirience I would be glad to find out what they did yto solve it.
"



"same problems here - i have been browsing the forums for weeks now and i have very bad news for you and for myself and all guys who bought SLI with 7900GTX and running dual core AMD processor machines.

Well it seems that currently there are no solution to our problems at all. We all see:

- random monitor sync losses after 3D play
- duplicate "ghosty" object to the real object if you fast turn, or move in games
- time sync problems in games like counter strike - when you go straight ahead you suddenly set back 2 metres then back where you were this whole "effect" happens in a fragment of sec
- laggy stuttering gameplay - while you get nice benchmark scores - for eg Half Life 2 goes with 120+ fps for me but if strafe 2 metres from a wall paralell to the wall then i see the wall mounted objects moving very very stuttered
- 15 -20 secs freezes, after which you can go on sometimes as nothing would happened, sometimes you get hard crash with nv4_xxxxx.sys error

Well according to my findings all these problems are related to the dual core CPU and the inmature operating system which does not capable of handling it properly.

If anyone has a real solution then we all would love our cards - cos i see the power in them but currently it cannot be used at all. Maybe with Windows Vista - who knows?

George"
i guess i'm out of luck with this problem