So, way back on page 86 (you guys post a lot), this happened:
Since my post, I upgraded to the suggested cooler (and am very happy with it), and as a result was able to overclock my i7 920 2,66 GHz to 3,4 GHz. It hardly qualifies as overclocking though, I just increased BCLK and rebooted, never looked back. That obviously helped the CPU be "workable" and it ran fine, but curiosity killed the cat, so I finally pulled the trigger on an X5690 3,46 GHz 6C12T at ~US$100 shipped on eBay.
I tried a much more methodic approach to overclocking that calls for isolating factors. So with the CPU multiplier locked at 20 (lowest in BIOS), I learned that my system will happily run at a BCLK of 200. Probably more as well, but didn't feel comfortable going further. I realized something that basically became a question that I hope you can help me answer:
I can reach 4 GHz through 200 x 20, but also e.g. through 148 x 27. Both seem to have advantages and disadvantages, so I'd like clarification on which to prefer. I haven't been able to find a decent reply to this anywhere - only replies that basically scream 'hearsay'. So where else to turn, but the experts?
- BCLK 200 should in theory make the rest of my system faster. In return, I loose the automatic ramping up and down of CPU speed (good for thermals and power bill?)
- BCLK 148 allows me to leave the CPU multiplier setting on Auto, letting the multiplier ramp up and down by demand. In return, obviously the BCLK is slower.
So what I don't seem to be able to find a decent answer to is; which parameter should I give priority? I am unsure if a higher BCLK is actually going to result in a faster system, or if it's cancelled out by the ratios adjusting things back down (I did notice the QPI link speed increase A LOT though)? And also I am unsure if the lower BCLK which allows for automatic multipliers helps my system run cooler and also reduces energy costs? The temperatures I saw were similar with both setups, so I don't know?
Current settings are 155 x Auto resulting in 4,185 GHz. During normal desktop use, this results in core temps 29-42°C (there are fairly big differences between cores), while under full load temperatures go as high as 84 °C on 4/6 cores, but doesn't seem to go higher ever. It's being cooled by an active air cooler in a relatively poor case. All of this is without tweaking voltages, since I don't really feel that I understand those enough.
Specs; ASUS P6T DELUXE (X58), X5690 @ 4,185 GHz, 24 GB DDR3 Triple Channel, nVidia GTX 660.
If it matters, my general plans are to build a new complete system in the fall/winter, as I expect GPU prices to drop. I guess I'd do my research in Autumn and hope for some really good deals on Black Friday. This has been really interesting though; I've built plenty of PCs, but never cared about e.g. cases. I now look forward to finding cases with proper thermal management and maybe even mod them to improve it even further.
Thanks to
@Knoxx29 in particular for the great recommendations!