memory compatibility question

i was looking to buy the gigabyte P35 DS3L which has a standard mem of DDR21066. does this mean only DDR2 1066 will work with the board or does it mean any DDR2 memory slower than that is compatible for example 4gb of corsair xms DDR2 800 PC 6400?

Yes... All DDR 1066 and higher is just DDR800 that has been overclocked or proven to run at those speeds. Your mobo says that it can run 1066 speeds stably but when you get the 1066 and instal it the speed will be defaulted to 667 or 800. It will not auto run at 1066. In other words you will have to manually set or overclock it to those speeds. If you buy 800 speed memory the odds of it running stably at 1066 are slim to none. Once again 1066 is just 800 speed memory that has been tested to run at 1066 speeds. So if you want the added benefit of 1066 memory make sure your memory that you put in the motherboard is 1066 speeds.