A Look at the Athlon 64

The migration of the memory controller from the North Bridge to an on-die solution is a big architectural change. A big advantage is the reduction of DRAM latency; this is especially important in when dealing in large datasets that require frequent memory access. The onboard cache size has also doubled in size compared to the XP line from 512 KB to 1 megabyte. This is subject to change though as the Athlon 64 3000+ only has 512 KB of cache. Rumor has it that the 3000+ are actually 3200+ with cache problems so half of the 1 Meg cache is simply disabled. The Athlon 64 has a separate bus for the memory and system unlike the P4/AMD XP architecture. This allows the Athlon 64 to support DDR ram as slow as 1600 and all the way up to 3200. The system bus uses AMD's Hyper Transport technology and runs at 1600 Mhz as opposed to the traditional 400 Mhz FSB on the AMD XP series and 800 Mhz on the P4s.

The packaging of the Athlon 64 has moved away from the exposed core from the Pentium 3 days to one that is concealed by a solid die like the Pentium 4. It is so similar in fact that it looks very similar to the P4. The days of crushing cores accidentally are finally over. Somewhat of a drawback is that this means that traces on top of the CPU packaging are no longer accessible meaning no pencil tricks, no defrosting kits or whatever tool the enthusiast used to adjust multiplier settings. The word around the hood is that all Athlon 64s will be multiplier locked and only the enthusiast FX line will have an unlocked multiplier. This is an understandable strategy from AMD as they do not want their high end products to get cannibalized by the lower end offerings. The situation is exacerbated with shady businesses that sell overclocked systems to unsuspecting users. It is a shame that it has come down to this but enthusiasts should be thankful that AMD allowed this to go on for so long.

Heatsink mounting is also simplified. The heatsink just simply latched on to the mounting clips and a lever pushes it down and makes contact with the heatsink. It is very similar to the Pentium4 design but seems a bit more refined.