Socket 754 vs. 939

Question

I'm buying a new board and want to know what the difference is between a socket 754 and a socket 939 which shoul I go with?

Answer 1

Socket 754 vs. 939:
Socket 754 CPU:
Single Channel Memory only
64bit DDR SDRAM at 100, 133, 166, and 200Mhz
Three DIMM's supported
800Mhz Hyper Transport Bus Speed
Runs hotter than socket 939 cpu's
Consumes more power than socket 939's
Socket 939 CPU:
Dual Channel Memory
128bit DDR SDRAM at 100, 133, 166, and 200Mhz
Four DIMM's supported
1000Mhz Hyper Transport Bus Speed
Runs cooler than socket 754 cpu's
Consumes less power than socket 754's
The new socket 939 cpu's now support dual-channel memory configurations. Socket 754 users are tied down to using single-channel memory. The addition of dual-channel memory ability effectively doubled the memory bandwidth of the on-die memory controller. Remember, the Athlon64 cpu's do not have to reply on a northbridge to transfer memory and graphics data to and from the cpu. This, in theory, results in much lower latency and higher bandwidth. Socket 754 cpu's support 64bit DDR SDRAM at 100, 133, 166, and 200Mhz. Now the socket 939 cpu's support 128bit memory at the same frequencies, so you can see the obvious advantage there. The newer socket 939 cpu's memory controller also supports up to four unbufferred dims, whereas the socket 754 solution only supported three. The 939's also benefit from a faster Hyper Transport bus speed(read front side bus). Socket 754 was limited to 800Mhz or 3.2Gb/sec in each direction but now 939 cpu's get a full 1000Mhz or 4Gb/sec in each direction. Generally speaking, the 939 cpu's are running cooler than their socket 754 counterparts, I would say mostly due to the fact that the socket 939 cpu requires less voltage. So, as you can see there are several reason's why a socket 939 Athlon64 cpu may be the better buy when compared to socket 754, especially considering the price difference is hardly even $50 on average from 754 to 939 in the same class, i.e. 3200+ socket 754 vs. 3200+ socket 939.
taken from
http://www.amdreview.com/reviews.php?rev=3000-3200-90nm