Hi All,
Now my vid card isn't an ATI card but this may be revelant.
I got a EVGA GTX 560ti SC vid card & i would get what y'all are describing--most of the time my screen would pause for 1-2 secs then resume but on occassion would BSOD. When I would check my vid card in Afterburner I could see that the card was downclocking during gameplay--thought drivers so I installed the latest drivers (270.61's)--no change. Put the 266.66's back in--no change. I pulled the vid card's HSF & put some OCZ Freeze on it which dropped the load temps 10*C on the vid card but I still got the pauses/BSOD's. I have a PC P&C Silencer 750W PSU w/ 60A 12v single rail--holding steady on power. I have a Intel C2D E8600 OC'd to 4.0 Ghz (bumped FSB to 1600 w/ no voltage increase) & never had an issue in the past. Ran Memtest on both DIMMS--both checked out w/ flying colors. Checked HDD's--both checked out OK. I would recheck Afterburner periodically & would start to see the mem usage of the vid card drop along w/ the GPU/mem downclocks then recover along w/ the clocks as well---hmmmmmmmm.
I shut down my A/V (Kapersky) & Win Defender thinking this was the culprit--no change. My EVGA GTX 470 SC vid card ran just fine when I had it in this box before (ran it on 266.66's). I was at the end of my wits today & was gonna swap out vid cards & call EVGA for an RMA on the 560 when I got a whim to go into BIOS & put CPU back to stock clocks--rebooted box & went flying--all ran beautifully--absolutely no issues at all. Hmmmmmmm..........
That got me to thinking so I went back into the mobo (EVGA 780i FTW) BIOS & got to looking around & found where I had set the CPU FSB voltage from the AUTO set & locked it at 1.25v (this set was the highest green set) because the AUTO set would set the FSB voltage at 1.325v (which was red) when I set the FSB clocks up from 1333 to 1600 (to OC the CPU to 4.0 Ghz). I did this back when I had originally OC'd the 8600 to keep the mobo safe (in all green settings). I put this back in AUTO & let the mobo set the FSB voltage back to 1.325 & set the FSB clocks back to 1600 to get my 4.0 Ghz CPU speed back & rebooted my box & went up--all ran beautifully--no pauses/BSOD's--I got some stuttering on control inputs initially but I went into the vid card's drivers & set the prerendered frames setting to 0 & went back up--all cleared up & running beautifully! I am 1 HAPPY camper now!!!
It appeared that the FSB on my mobo just couldn't handle the bandwidth output of the 560ti SC at it's clock speed, controller inputs & game running on the CPU at the locked voltage set of 1.25v & would become unstable & cause the vid card to stumble so the vid card drivers would attempt to recover the card-when this was going on the bandwidth demand would drop so the CPU would recover along w/ the vid card & all was well again--until the FSB got overloaded again! When I put the mobo BIOS back in control the BIOS would adjust the power to suit the demand & voila! no issues!
You might check for this on y'all's setups as I can see the latest ATI vid cards (especially OC'd vid cards) can cause the same issues, especially on the older mobos (like mine). My 470 SC clocks at 625/1350/1701 stock, my 560Ti SC clocks at 900/1800/2108 stock--that's a BIG jump in GPU bandwidth output between the 2. The issue wasn't the PCI-E bus lanes, it was the FSB power/bandwidth between the CPU/mem/PCI-E bus (caused by me--
).
Hope this helps!