DDR3-800 is probably irrelevant in the consumer space. No one would think of purchasing this slow memory given today’s nonexistent price differences versus DDR3-1066. However, since binning for slow memory can help a manufacturer increase its yield, we’re still seeing some low-cost business PCs still shipping with this memory type. In addition, notebook designs may opt for slower clock speeds in order to reduce power consumption.
We first used DDR3-800 at CL6-6-6-18 speeds.
Since there are various types of DDR3-1066 memory available, we decided to run it at slow CL8-8-8-24 timings first, which can be considered average. This is what you’ll usually get when you buy an ordinary office PC with DDR3 memory.
Next, we ran the DDR3-1066 at faster CL6-6-6-18 timings. Although most memory should be capable of running at these speeds, you should probably look for vendor-specified fast timings rather than overclocking, just to be on the safe side, especially if you're hoping for even higher data transfer rates.