Ram speeed

Ok, thanks. So if you only have one ddr2 ram chip instead of 2 chips, it wont be ddr2?mark30001

DDR2 is the second generation of DDR ram, the current gen is DDR3. If you have one chip youwill be running in single channel but it always be DDR2. WRT running in dual channel this iscommon practice and in essence doublesyour bandwidth thus highly recommended.

do boards that support 1066 mhz memory and up support 800 mhz memory?

They all should... At least, all the once I've seen on newegg's site are 800mhz based.

1066 is really a hype from a manufaturer standpoint... to sell them, I mean. Like I said earlier, the manual will tend to tell you that it only recommeded to use 1066mhz in single channel mode. And there is no toggle or jumper that activates Duel channel versus Single Channel. Channel selection is activated by which slots you install your sticks into and if they are of the same memory size. Which basicly means.... if you wanna follow their recommendations, half your DiMM slots on your board must be empty to activate 1066mhz via. their own recommendation.

As I understand it, the motherboard's bios won't adjust the settings automaticly to 1066mhz timing, if you plug the 1066 sticks in a dual channel configuration... It'll only actiavte it, itself, if you do a single channel configuration. But, you can still go in there yourself, and set the stuff manually.....

Also, considering their hidden recommendation (hidden because you don't know it's there until you read the manual in most cases. Newegg has a subnote on some the motherboards there, but not all of them; about the subject).... the loss of Duel Channel Mode turns the 1066mhz benefit, more of a substitution for dual channel mode. So, just about everyone ignores that manufacture recommendation, plugs inthe sticks into a duelchannel configuration,and overrides the memory timing settings, manually. Which is basicly the same as overclocking.

here's an example of the warning: http://www.newegg.com/Product/Product.aspx?Item=N82E16813131320

DDR2 1066
*Due to AMD CPU limitation, DDR2 1066 is supported by AM2+ CPU for one DIMM per channel only.newegg

As for quickly finding out if your PC is in dual channel mode... CPU-Z is the fastest that I've found that will tell you: http://www.cpuid.com/cpuz.php(Channels #)

what motherboard do you currently have? i know my board supports DDR2 1066 but only on AM2+ CPUs which are the phenoms(quad cores).

i would check to see if your boardhas a limitation like this aswell.

also running RAM at 1066 you may have to change a setting in the BIOS, DTC unganed mode set to always. i had to do this for my RAM to be recognized as 1066 instead of 800.

you also may need to manually change the RAM speed to 533(1066). its in that format because DDR stands for double data rate so RAM rated at 533Mhz is actually 1066Mhz because its 533x2 on one stick.