My old desktop was running a Phenom X3 8450 triple core processor. The clock speed was 2.1Ghz. It was blazingly faster for running Windows XP and Windows 7.
But two days ago, I noticed this Athlon II X2 245 processor running at 2.9Ghz for $66
with free shipping. As those who are educated know, this is a 45nm chip built on the K10.5 Shanghai technology. Since the total Ghz is 2x2.9 = 5.8 Ghz, while the 8450 was 6.3, I guess this processor will be faster than the old one, but at only 65 watts.
Today, the processor arrived, and within five minutes, the new CPU is running. Much faster at lower power consumption. Windows 7 shows the new CPU performance at 6.4, up from 6.0 with the 8450. You can feel the difference.
Unlike those Core i7 folks who always need to change the whole CPU, motherboard and memory set, with AMD, you just swap the CPU. The AM3 Athlon II is backward compatible with old AM2 motherboards. Its integrated memory controller does both DDR3 and DDR2.