DDR3-1333 is currently the mainstream speed for DDR3, providing clearly better memory performance than DDR2-800, while still being reasonably-priced. Today, 4GB dual-channel kits still offer the best bang for the buck, but 8GB dual-channel DIMM kits should soon be available in decent quantities, albeit at higher prices, obviously. If you look at entry-level DDR3-1333 memory, you’ll probably only see CL10-10-10-26 timings, which is what we used first.
CL7-7-7-20 timings are tight—one of the fastest industry standard timings available today—and won’t be possible on as many DDR3 solutions. Going to CL6 would no longer be specified by JEDEC, and probably be expensive enough to render this configuration unreasonable compared to faster clock rates at slightly reduced timings.
Again, we started testing DDR3-1600 at relaxed timings of CL11-11-11-30.
Finally, we also ran tests using DDR3-1600 at more aggressive CL8-8-8-24 timings.