Asus websites says both mobos support AM3 chips. So is there any advantage to getting the M4A78? w/o the mail in rebate the price difference is only $7. So if its a better board in any way I'd get the M4A78.
As for memory when it says "DDR2 1066 is supported by AM2+/AM3 CPU for one DIMM per channel only" what does one DIMM per channel mean? Is it one memory stick per each dual channel? I guess the bottom line is I want to find out if I were to get AMD Regor 250 chip and one of the above mobos with 1066 memory (which is only $5 more that DDR800 memory) will that work well with this build? Thanks for your help.
If you get a AM3 motherboard you will be able to use DDR3 memory as opposed to an AM2+(most support AM3 chips after bios flash) motherboard that will only support DDR2 memory. So in other words you are better off getting an AM3 board.
m4a78-em will run am3 with bios update , but will NOT run ddr3 memory! As for m3a78-em, it runs ddr2 memory as well, but only runs in a green mode at 800mhz. it will run at 1066 , but only if you overclock it!!!!Which takes you out of green mode. Running 1066 Memory on either board will require am2+ cpu.
Also both boards are based on 780g which has onboard video output at 60hz. If you want more you may want to step up to the 790g series. Although it comes with a price jump it may be ddr3 friendly..
I suggest always checking the Qualified Vendors List or QVL , so you dont wast $$ on parts that wont work !!!!!! The m4a78-em , PowerDVD9 , XBMC ,a big screen and some good sound and you will love your HTPC
!!! I hope this helps ...