AMD Athlon 64-Bit CPUs ExplainedFormer staff writer -
AMD Athlon 64 FX-xx
The current Athlon 64 FX-xx processors have a 940-pin chip with a huge metal heat spreader on top that resembles what we’ve seen on the Intel Pentium IV processors.
Like the Athlon XP, the Athlon 64 FX-xx has support for Dual Channel DDR (aka DDDR or DCDDR by some), however the memory controller is no longer controlled by the motherboard. The Athlon 64 FX-xx has the memory controller located - die, and supports Dual 64-bit DDR memory channels, giving it a 128-bit memory bus. One thing to keep in mind if you are going to buy an Athlon 64 FX-xx processor is that it requires the use of registered memory.
The Athlon 64 FX-xx is almost the same processor as the AMD Opteron, with just a couple differences. The Opteron and 64 FX-xx differ in that the Opteron has three HyperTransport links, whereas the Athlon 64 FX-xx only has one HyperTransport link. According to AMD, the two processors are also tested to different electrical specifications.
The Athlon 64 FX-xx processor also has the “largest on-die cache of PCs”.† How much cache are we talking? 128KB L1 cache (64KB instruction + 64KB data) and 1MB L2 cache.
While there aren’t many operating systems that currently support the AMD 64, the AMD 64 FX-xx will run on all 32-bit x86 operating systems.