NEED SERIOUS HELP WITH MY 512meg 7900gt's - THEY ARE doing crazy stuff!

[ttimbo75]

Hey all. I have 2 x 7900gt's. I ditched my 7800gtx for them. The issue I am having is that they do not seem to be overclocking properly. I can overclock one of them without SLI enabled, but enabeling sli kiils them with the overclock, screen goes bananas then the pc locks up. I am using coolbits to OC. As I am a n00b to overclocking, can anyone let me know how I can overclock these beasts? They are Xpertvision 7900GT 512 meg sonics. Do I need to upgrade their bios's or something? Please help. Thanks all!

 

[sintaxera]

You sure picked a heck of a way to get into overclocking. There are so many possibilities here it isn't even funny. Here are some things to check.

1) Just because they are the same 'card' doesn't mean they can overclock the same. Test each one out on it's own (no SLI, take the other out of the system) to see what clocks it can get too reliably. Do the same for the other card. Go with the lowest speed both can do independently.

2) Your power supply might not be able to handle the load of the overclocked cards.

3) Your case might not be able to expel all the heat building up from the overclocked cards.

4) Your motherboards implementation of SLI may be very sensitive to timing dicrepencies from the overclocked cards.

5) You could just be out of luck.

 

[Modular]

What drivers are you using? There's a thread somewhere (here or in the Video section) that says that the newer drivers revert overclocks back to default once they are applied. Many believe that this is nVidia's answer to increased RMA's from the overclocked and voltmodded 7900gt's...

 

[ttimbo75]

hey, thanks for the replies, here are my system specs:

Thermaltake Kandalf case
4200+ X2
A8N32-SLI deluxe
2 GB Dual Channel Cosair TWINX2048-3500LLPRO
2 x 512meg 7900GT Sonics
2 x 300GB SATA 2 Seagate HDD'S 16meg cache in raid 0
Creative Fatal1ty sound Card & IR Drive
2 x LG 16x DVDRW
Antec Phantom 500w PSU
Thermaltake Symphony watercooling with 2 x Zalman GPU waterblocks & 2 x waterchill full size HDD waterblocks
2 x 19 inch Samsung 940B LCD's
Logitech Z5500D 5.1 speakers
Logitech G15 Keyboard
2 x 250GB SATA 2 external Seagate HDDS
AverTV HDTV 1080i Digital TV Tuner
Motorola SB5100 Cable Modem
D-Link DVG-G1402S Wireless VoIP Router with a Uniden 5.8GHZ Bluetooth handset
CyberSnipa Flexiglow Game Pad
Logitec Cordless Rumblepad 2
Thermaltake Xtunner Remote fan controller
KME 1000VA UPS

So as you can see, I really should have no dramas at all powering this gear. As for drivers, I am using the latest drivers from nvidia.

Ill give the swap video card idea a run too. Ill post back with the outcome - meanwhile - oters please feel free to chuck in your 10c worth!

 

[Smilin]

Dual 7900 GTs. Why are you overclocking them again?

 

[sintaxera]

If you get a decent overclock from both cards, and they still fail together, take out that AverTV HDTV 1080i Digital TV Tuner. My gut is telling me that it might be the culprit. That fancy X-Fi you have could also be wrecking some havoc:

http://xfi.blogspot.com/2006/06/soundblaster-x-fi-crackling-and.html