AMD Athlon 64 FX-62 And X2 5000+ Socket AM2, nForce 590 SLI & ATI RD580

Socket AM2 processors look very much like their socket 939 predecessors, only with an extra pin...

Socket AM2 For Athlon 64 More of the same killer performance, DDR2 enhanced and virtualized

939 Left, AM2 Right

Perhaps what might be considered as a more significant change is the 4-bolt heatsink tray that provides more durable and stable heatsink retention.  Unfortunately, those with screw mount heatsinks like those swank Zalman CNPS9500 coolers will have to wait for new retention clips to be designed for the new 4-hole mounting configuration. 

MODEL NUMBERS FOR AM2:
Most of the model numbers that you might be familiar with, were brought over from Socket 939 with their same cache and frequency specifications, though there are a few exceptions.  For example, the Athlon 64 FX-60 is a Socket 939 option only, and Socket AM2 now has an X2 4000+ which is not available in a socket 939 variant as a dual-core CPU. 

LOWER POWER CONSUMPTION:
Athlon 64 X2 processors now have a new, lower maximum power specification of 89 watts (down from 110) for socket AM2.  Standard single core Athlon 64 processors also have a lower max power specification - 62 watts (down from 89).  Semprons also have a 62 watt maximum specification.  Also, as previously announced, AMD is offering a line of Energy Efficient processors available in Socket AM2 for the desktop that have maximum wattage specifications of 65 watts and 35 watts.  These CPUs will retail for a slight premium.  AMD's "Energy Efficient Processors" deliver the same performance with the same core frequency and cache sizes but with lower heat dissipation and power consumption.  AMD's specified maximum power represents consumption under full load at the most extreme conditions.

Energy Efficient models available at 65 Watts max power:
AMD Athlon 64 X2 processors:   4800+, 4600+, 4400+, 4200+, 4000+, and 3800+

Energy Efficient models available at 35 Watts max power:
AMD Athlon 64 X2 processor:   3800+
AMD Athlon 64 processor:   3500+
AMD Sempron processors:   3400+, 3200+, and 3000+

NOTE: The third digit of a desktop processor's part number details the maximum power consumption of that model.
"A" denotes "normal" power
"O" denotes a 65 watt energy efficient processor
"D" denotes a 35 watt energy efficient, small form factor processor