Overclock problem

[Drafter]

Hello All..I recently upgraded my gpu to an XFX 7900 GS XXX from an ATI X800 SE. Prior to this upgrade, I was running a stable CPU overclock which I achieved by minimizing the divider to 14 and bumping the bus to 250mhz(1000mhz FSB). I installed the XFX card, booted up, all seemed fine(with the stock XP driver). After I installed the Nvidia driver, I was prompted to reboot. The machine would not start into windows. It would get to the detection screen and just keep restarting. I went into the BIOS and set everything to defaults and all was good...booted into windows no problem. I have since went back into the BIOS, lowered the divider to 14 again, but cannot get the machine to boot into windows with any bus speed higher than 215mhz. I would like to get my FSB back up to 1000mhz,any advice anyone can give me will be much appreciated. Thanks...

CPU-P4 550 @ 3.4 ghz
MB- DFI LanParty 915P-T12
RAM- 2x 1024mb Ultra DDR2 (4-4-4-11)
GPU-XFX 7900GS XXX
SOUND- SB Audigy2 ZS Platinum
PS- Ultra X-Connect 500w
HD- 2x 200GB WDC (No RAID)
OS- Windows XP Home SP2

[Scott]

Make sure you have the latest BIOS for your motherboard.

[Drafter]

Thanks Scott for your reply...I do have the latest BIOS, unfortunatly for me the last BIOS release for my mb from DFI was in January of '05. I know my gear is outdated, I'm just not ready ($$) to upgrade yet..Thanks again.

[Bio-Hazard]

Did you remember to uninstall all the old ATi drivers, they might for some unknown reason be causing some sort of conflict. Also run Driver Cleaner after the removal of the ATi drivers.

[Drafter]

:icon_tiphat:Bio-Hazard..You are the man!! You nailed it dead-on. I purchased a copy of Driver Cleaner PE and it worked!! I am back to my 1000mhz FSB. Thanks!!

[tyle6]

BIO, we need to get you a cape.

[Bio-Hazard]

LOL.....A XFX 8800GTS 320 will do...............:)

Glad it worked for you Drafter...............:)

[Drafter]

As much as it pains me to say it...its happening again. I got like 2 reboots out of it and its right back to where it was. When it was still running at 1000 mhz FSB, I ran 3dmark03 & 06, played some Battlefield2142 & all seemed fine(my 3dmark03 score went up 8000 points with the new XFX!!). I went into the BIOS and tweaked voltages, RAM timings & pretty much any other changeable items(except PCIe freq & the N/B strap setting..cuz i have no clue about those). Its like theres something not allowing me to get the bus speed past 215mhz. I got it running right now @ 215 x 17...giving me a FSB of 860mhz. At least I still have a 1:1 Dram/FSB ratio. Guess Im gonna have to live with that until I upgrade. I apologize for jumping the gun and sayin it was all fixed. Thanks again Bio for your help.

[Bio-Hazard]

Have you tried upping the vcore any at all? That may help, but it just sounds strange that only installing a new video card would cause that much of a problem.
Only thing and can think of right off the top of my head is that the new 7900GS is pulling alot more power through your board than what your old card was and that maybe one of the rails on your power supply is a little on the weak side. And when you try and clock higher than a certain point it draws to much power and causes the system not to boot. If you have a multi meter handy, you might want to test the 3 different rails and see if they are within spec at stock, then at your current OC and then again at your old, now failed OC.

[Drafter]

I have both connectors on the XFX cards power dongle connected to a single power supply cable with 2 connectors (actually the cable has 3 connectors, the floppy is running off it as well). Should I try to run a single cable (each off a different rail) to each of the 2 connectors on the dongle?? Also, my vcore voltage is at 1.32v...how far can I safely increase that??

[Bio-Hazard]

Keeping temps in mind, I wouldn't go over 1.5 volts on the vcore. Seeing as you're running air cooling you'll more than likely get to hot before you get that far.

You can try running the PCI-e power adapter off 2 different rails, but you still need to check to see if all your rails are still running within spec.