Let's see, 3.4/20=170. So you are using a 170Mhz FSB. With the memory's 8x multi, you're probably driving that ram at 8x170=1.3Ghz. Still well below the 1.6 rating. Hummm. Why do you think the CPU is temp limited? Have we locked down the i7's Tc/Tj numbers? For instance the last stepping of the Core2's went to 72/95C. The best cooler is the thermalright 120. Don't know about your's, but I kinda expect something else is limiting the system. What are your temps, and more importantly what is the Tj spec for that CPU. Initially, there was also chatter about a thermal limit function that needed to be disabled in the bios. Also, I'm hearing that 175 is about it for the Base clock . . . but then hear boasts of 220Mhz. To find out, turn down the CPU multiplier to its lowest setting and raise BCK until it won't go no more. That's the BCK's limit. Just a couple of things to check. I expect though, you will end up being BCLK limited at significantly less than 200Mhz (x 20 = 4.0Ghz).

I am at 3.4ghz right now with the 920 working at 1600 DDR3....my cooler will not let me go to 4ghz....will I see much difference if I go to 4ghz and what cooler would you recommend? Here is the one I use. It just can't move enough air.http://www.newegg.com/Product/Product.aspx...N82E16835106124 Regards

3.4GHz to 4GHz will make a noticable difference. But the best cooler for the job is either the Thermalright Ultra 120 Extreme or the OCz Vindetta2. There are other coolers like the Vindetta2 that seem to work just as well too, they have essentially the same design. And turn off hyperthreading. FSX won't use it and HT adds over 10 deg C to your load temps, I've seen that myself. What's working here is the combination of the faster memory and the faster cpu. Overclocking the i7 gives way more payoff than overclocking the Penryns or the Kentsfields.-jkOne more thing:Make sure you get your i7 overclocking advice from someone who ACTUALLY HAS ONE, and not from some guy with a Q6600 trying to teach others how to run an i7.-jk

Interesting link, thanks. LOL I see they don't really include my old dated CPU in most benchs today haha!!!

3.4GHz to 4GHz will make a noticable difference. But the best cooler for the job is either the Thermalright Ultra 120 Extreme or the OCz Vindetta2. There are other coolers like the Vindetta2 that seem to work just as well too, they have essentially the same design. And turn off hyperthreading. FSX won't use it and HT adds over 10 deg C to your load temps, I've seen that myself. What's working here is the combination of the faster memory and the faster cpu. Overclocking the i7 gives way more payoff than overclocking the Penryns or the Kentsfields.-jkOne more thing:Make sure you get your i7 overclocking advice from someone who ACTUALLY HAS ONE, and not from some guy with a Q6600 trying to teach others how to run an i7.-jk

While I have not witnessed the 10c increase to load temps with HT off (I have yet to check to be honest), there is one thing I have nolticed that I find quite interesting. Turning HT "off" eliminates any of the stuttering I have seen. I am not sure if anybody remembers or not, but HT caused a few stuttering issues with FS2004 (or was it FS2002) back in the day when using RealityXP avionics (if I remember correctly). Using the DX10 option eliminated a good deal of stutters and really smoothed things out, however, turning HT "off" in my bios pretty much completely eliminated any stutters in both DX9 and DX10 and I don't see ANY difference in actual FPS. Food for thought, or at least worth a try if one has a few minutes to mess with their bios settings.