Hey there, I'm sure this question has been asked before, and I've looked around, but I can't find specific answers to my questions. Let me first start off with my setup: Q6700, eVGA 750i FTW, XFX GTX 260 Core 216 Black Edition, Cooler Master 690 nVidia Edition Case, OCZ Vendetta CPU cooler, 2x2GB OCZ SLI PC2-6400, standard HDD and standard DVD drives. All fans are on 100%.
Right now, I'm OCing my FSB to 400 mhz, and using 9x multiplier. I set the CPU to 1.5v, and haven't touched anything else (except my RAM at 2.2v). I turned off C1E and all that good stuff, and I idle between 35-40 C. I don't think heat is a big issue right now, but I can always lower the CPU voltage. I want to run my PC at a stable OC.
My questions are:
1) Is 400 mhz FSB and 9x multiplier a good setup? Any better recommendations?
2) How should I lower my CPU voltage while still keeping it stable? How low should it be able to go at these settings?
3) Do I need to touch any of the other voltage settings (northbridge, southbridge, etc.)?
4) Is it OK if I push my RAM past the 800 mhz it is intended for?
At 9x400 your running 1:1 ram ratio with the system. If your running ddr2 800 mhz through a divider, your ram latency will be higher than without (1:1 ratio). So 9x400 is the best setup for your ram, as it runs at 1:1 ratio and is not under clocked. At 1066 your over clocking the ram by 266mhz which in most cases is too high, and definitely too high using 1T timings.
Over clocking is mostly trial and error... You can't just set a given FSB number and play a game, and expect everything to be great. You need to change settings, try to boot into windows, then run test. If FSB of 350 didn't work well, then try 351, 352 and so on, until you find the sweet spot.
Just make sure you keep your ram as close to specification as possible, while going through that process. That means using different dividers for the ram.
Thanks for the tips. I decided to stick with the 1:1 ration @ 400 FSB (800 mhz effective for RAM) and 9x CPU multiplier. I'm quite happy with the low temperatures I'm getting from this 3.6 GHz OC (around 30-35 idle, 40-45 load), so I won't be pushing it any further. I think my PC is stable atm, but I haven't properly tested it yet (other than playing games, etc.) I was just wondering if you could tell me if these voltages seem normal.
1.45 v for CPU set in bios (drops to 1.4v during heavy usage, even drops to 1.392v at times in GTA IV)
1.3v FSB (highest voltage that was in the "green zone" in BIOS)
2.1v RAM (OCZ protects me even if I'm using 2.2v, so I'm not worried here)
1.45v SPP (Northbridge; again, highest settings in the green)
1.25v for NF200 (the chip that's reponsible for generating 32 lanes for dual PCIe on 750i FTW Edition boards exclusively; I left this low since I run only one GPU atm)
If any of these voltages seem much too high/low, please tell me. This is my first time OCing, so I want to make sure I'm on the right track. xD
Oh yeah, I was wrong about my RAM, it's actually 800 MHz 5-4-4-15 2T, so I just set it to that stock clock (seems fast enough for me).
The initial difference in voltage from bios to cpu at idle is "vdrop", and is normal. It will drop further do to "vdroop", which will change slightly depending on the load on the cpu and is also normal.
Try running your nb voltage at 1.4, if it's not stable then go back up, but I would try to keep it under 1.5 for the long haul. The rule of thumb is, use the smallest voltage value you need to remain stable. Less heat and less wear and tear on the parts.
Thanks for all the help sportsfanboy. For some reason though, I'm still just not getting it. Maybe I'm not using the proper procedure or something. In a 15 minute OCCT test, the only stable OC I've gotten was 400 FSB x8 CPU for a total of 3.2 GHz. All my 3.6 GHz (400 FSB x9 CPU) tests have failed, even with my CPU set to 1.5v in BIOS and other voltages set pretty high. I just don't understand what I'm doing wrong. Does my CPU just not like the 400 MHz FSB? Please enlighten me on the proper overclocking procedure I should be using. Thanks in advance...
PS: Is the pencil mod worth doing in my case? Is the massive vdroop causing instability?
Hehe, I feel kinda silly for asking this, but is there any way to take a screenshot in bios? I can always take a physical picture with a camera if need be. I think I might have figured out what was wrong though. It's a combination of my CPU's high VID of1.325v and large vdroops I've been getting. So although I could boot my computer at 3.2 GHz (320x10) with stock 1.325v, it wasn't stable at all (although I thought it was). OCCT testing showed me that large vdroops caused instability. On those frequencies, I set my CPU to 1.375v and it didn't pass the OCCT test, so I tried 1.4v, and it passed. That's where I'm at right now. Only problem is, if I need 1.4v to run 3.2 GHz stable, I'm not going to be able to overclock much more, unless I really push my CPU all the way to 1.5v, which I don't think is recommended. My only other option would be the pencil mod. Is that recommended?
Oh yeah, I forgot to mention how big my vdroop was compared to BIOS settings. During the OCCT test at 1.4v (3.2 GHz), the voltage dropped all the way to 1.34v during most of the test, and even 1.33v at times. I think that's really unacceptable. What's the point of the vdroop feature, anyway?
Vdroop isn't a feature, rather a behavior of electric current under increased resistance. Are you sure your not overclocking your ram while your messing around with your cpu settings? Because 1.4 on vcore seems like a lot of voltage for 3.2ghz. If you can take a picture or two of the main overclocking page and post it, maybe myself or someone else could help.
Also keep in mind that all cpu's and mother boards are different, even if they have the same model number. So one chip or motherboard may overclock better or worse than the next.
When I was doing my 3.6 GHz tests (400 FSB x9 CPU), CPU voltage was at 1.5v, RAM was at 2.1v, FSB was at 1.3v, SPP was at 1.5v and NF200 chip was at 1.25v.
Also, I had disabled C1E and all the CPU features. Spread spectrums were also all turned off. Fans were at 100%.
Edit: Just got a "stable" overclock (except OCCT quit 7 seconds before the test was over because my CPU hit 70 C). The FSB was at 1550 with 9x multiplier for 3.4875 GHz. I got it stable at 1.5v set in BIOS (1.47 idle, 1.43 @ over 99% load). I gotta say there's no way I want my CPU running at 1.5v or hitting anywhere near 70 C ever again. Intel has disappointed me on this chip... I know my cooling isn't the best, but it's decent. There's no way my Q6700 should need 1.5v to hit just under 3.5 GHz. If I try anything under, windows crashes during OCCT testing. For example, I tried 400 MHz FSB x9 for 3.6 GHz @ 1.497v, and it didn't pass. This sucks
Edit 2: I finally found a stable overclock I'm content with. I'm at 350 MHz FSB and 10x multiplier and 1.475v as set in BIOS. When I lowered my voltage one notch in the BIOS, OCCT failed when the CPU voltage dropped to just under 1.38 ish. I'm guessing 1.38v is therefore the lowest voltage that will support my CPU @ 3.5 GHz. I think my most CPU intense PC usage is GTA IV, and the CPU voltage only drops to 1.42 when playing. Does this mean it's safe for me to lower my CPU voltage in my BIOS as long as I never drop below 1.38v during GTA IV? Are there any other times where CPU is used more (I can't think of any, but maybe startup might require all cores at 100%?).
Overall, I'm not too displeased anymore. I even have C1E enabled and my PC is still stable. My main concern is whether or not you'd suggest I drop my CPU voltage like I described. Also, is 1.4v for the FSB safe? I'm using an eVGA 750i FTW board, if that helps.