Hi guys. I wasn't sure if I should put this in the OC forum, but it's not really about overclocking, more of limitations of the P55 chipset I guess.
So anyway, I have my mobo pretty filled up. In fact, when gaming I'm quite sure that I've totally maxed my bandwidth. I have CF 5850s that are OCed and running at 8x/8x on the main PCIe 2.0 lanes. Those are fine... the question comes when talking about the south bridge PCH.
So, the south bridge is where everything else attaches. I have 2 HDDs in RAID 0, an AuzenTech Bravura 7.1 soundcard in a 1x slot, and a GT 240 for PhysX in the 4x slot.
The main question is, should I increase the PCH voltage any? The reason I ask is I've had some odd issues while gaming but I can't tell if it's just the games or drivers or something else.
For one, Cryostasis. The game generally runs fine with everything maxed out at 1920x1080 and with hardware PhysX on. But completely randomly, it will freeze up and crash. It doesn't seem to happen at times that there'd be lots of PhysX stuff going on but who knows. Sometimes when it does this, it doesn't crash and I need to do a hard reboot.
Last night, I was playing Starcraft 2 2v2 with a friend. About 30 mins in I got a BSOD. Now first of all, I played at the end of the last Beta stage and the game didn't work right unless I disabled CF. Now it works fine - might be new drivers/ATI CF profiles, the updated Beta, or it might be the CCC A.I. setting on Standard (last beta it worked only if disabled). Anyway I had already played a few matches, and played a few more after this happened so I don't know where the BSOD came from. And yes my system was stable, 10 hours Prime95 as well as 15 Intel Burn Test passes.
I've also had some random freezes in STALKER although I haven't tried that game since installing the PhysX card. I'm fairly confident the issues went away after dropping the GPU mem from 1210 to 1200. I now have it at 1190 hoping to fix the "new" issues.
I thought it might be my 5850 OCs, so I dropped them down some more but still got the Cryostasis freezes and the SC2 BSOD was also after that. Previously I had already spent many hours in Crysis and Metro 2033 with the same OC. Speaking of Metro, it played rather well but on a couple occasions it froze and crashed too.
As for my CPU OC, I've decided that with Intel's revision of the i5 750 max voltages (from 1.55 core/1.21 VTT to 1.4/1.4) I want to redo my OC. Same speed (175x20 with turbo and EIST/C1E/CStates) but I'm going to try lowering the Vcore a little while raising the VTT (previously 1.30625V Vcore and 1.206V VTT). I'm hoping the issue might be solved with the slightly higher VTT, since CPU stress tests don't really work your IMC hard as that is what's also controlling the PCIe lanes that my GPUs are on.
However, I think that it's possible some PCH voltage will help smooth things out. Or not?? Stock I think is 1.05V, I might try 1.1V and see what happens... I guess this will be a long drawn out process for me as I first want to get my CPU OC voltages fine tuned (I think I'm at 1.28 core/1.23 VTT and it passed Intel Burn Test but haven't done Prime95). Then again, could be the crashes are from the GPU mem or core clocks. Tho, fairly certain those are ok (I've done my FurMark tests and plenty of gaming).
If it's not the GPU clocks, and if it's not the VTT/IMC, then that only leaves PCH right? Well, that or drivers or bad coding in the games themselves.
Sorry for the novel, but any suggestions/tips/useful info is appreciated!