It was September 2003 when we last saw an Athlon64 FX break cover. That of course was the much applauded, if slightly pricey 2.2GHz FX-51. The latest FX CPU from AMD is the FX-53, featuring an architecturally identical core to the FX-51 but running instead at a slightly faster core speed of 2.4GHz.
The “FX” range of processors is aimed very much at the “prosumer” or enthusiast market. It’s more costly than the more mainstream Athlon64 but also performs better due mainly to its 128bit integrated memory controller. The standard Athlon64 also features an integral memory controller but at only 64bits wide it offers significantly lower bandwidth and as a result this pegs back its performance levels in some situations.
Like the Athlon64, the FX-53 features a 0.13 micron core on which there resides some 105.9 million transistors. That sounds a lot but in comparison, the soon-to-be-released NV40 GPU from nVidia is rumoured to feature over 200 million transistors!
Onboard cache comprises 64Kb of L1 data cache and 64Kb of L1 Instruction cache, combined with 1024Kb of L2 cache for an effective total of 1152K. Keeping the memory bus whizzing along, the integrated 128bit dual channel memory controller also operates at the full core speed meaning, in this case, 2.40GHz. With both memory, bus and the northbridge components all running synchronously with the core, any boost in CPU frequency brings with it immediate benefits in these other areas too by default, making for a processor that should scale very nicely as its speeds grow.
The great news for all AMD users is that the new range of 64bit processors, including the 64 and FX, now have their ceramic packaging and die protected by a copper heat spreader, a-la-Intel. This may not sound like a praiseworthy innovation unless you happen to be someone who has suffered the “crunch of death”; a not uncommon sound created by fragile 32bit Athlon cores splintering to destruction as you apply the heatsink. Interestingly the heat spreader doesn’t seem to feature a vent hole as is seen on Intel’s part.
The FX-53 is still a Socket-940 part and it seems AMD will sell Socket-940 and the planned socket-939 CPUs side-by-side for at least a little while to come. The reasons for AMD’s decision to adopt Socket-939 aren’t entirely clear, but it certainly seems that it will allow motherboard manufacturers to opt for cheaper four-layer PCBs rather than the current six-layer versions, and to use regular DDR instead of registered DDR. In other words, they’ll be taming some of its slightly too elite, Opteron-like traits in favour of a product better suited to gamers and those whose needs are less “mission critical”. Something perhaps AMD should have done from the start considering how similarly the Opteron and FX perform.
My test system was supplied pre-built and pre-configured by AMD, so of course I went over it with a fine-tooth comb looking for anything that might give artificially high results. Not because AMD can’t be trusted, just because I have a deeply ingrained suspicious streak. I found nothing by the way.