It is virtually impossible to get 4 DIMMs working stably at 1600, no matter what raving half-assed review you've read that says otherwise with their "thorough" 5 minute "it boots windows" test.
DDR3 also tends to be quite underspecified/overstated.
My Patriot DDR3-1600 supposedly does 7-7-7-18-2T@
[email protected]. My mobo over-volts DIMMs by about 0.10V. I have to set DIMM voltage to 1.90V (+0.10V over spec, which ends up being +0.20V over spec) to get those timings stable - with a SINGLE pair of DIMMs.
With 4 DIMMs, however, I have managed to get it _almost_ stable at 9-8-8-20-2T@
[email protected] (2.40V measured). Yes, that's 2.40V!!! Don't do this unless you have a Corsair Dominator RAM cooler or similar. The DIMMs will reach temperatures more often associated with FB DIMMs. And it STILL isn't 100% stable (about 1 crash/error every day or two). FSB strap, NB voltage, transaction booster and everything else won't make a blind bit of difference (they'll make it worse if you push them too far, of course but even at 400 strap, booster at -8 and NB voltage all the way up to the redline won't actually make it work stably).
However - I HAVE been able to get 1500MHz stable (which is convenient since it is achievable with both 450MHz FSB and 500MHz FSB, both of which you are likely to be able to achieve with the E6600 - the last E6600 I tried handled 500FSB (I ran it at x6=3.00GHz). My Patriot DIMMs, however, seem to be stable at 7-7-7-18-1T (!!!!!) @ 1500MHz @ 2.30V (might be able to reduce that a bit, will look into it when I've verified this is 100% stable under 100% load for a week).
Also note that higher FSB (this is particularly important), faster command rate and faster timings are worth way more than an extra 100MHz on the memory clock speed in terms of memory bandwidth. 400 FSB with 1600 RAM at 9-8-8-20@1T is good for about 7.8GB/s. 450FSB with 1500 RAM at 7-7-7-18@1T is good for 9GB/s, and about half of that improvement comes from the extra 50MHz FSB.
But than again, I am running different RAM, so your results may differ.
