Physical bits
Just a quick page on the physical nature of an Athlon 64 X2. Built on AMD's 90nm process in fabs in Dresden, the ~200 million transistors that make up a dual-core X2, with each core having its own 1MiB of L2 cache memory, fit in the same die space that a 130nm 1MiB Opteron or Athlon FX does today.That impacts things thermally, with AMD using SOI and strained silicon process techniques to lower thermals for an equivalent 90nm product compared to its 130nm counterpart clocked the same and with the same amount of L2 cache memory.
With a 110W TDP, that means that the PIB (processor in box) cooler that AMD released with the 130nm single-core FX-55 product, is more than able to cool the entire X2 range up to 4800+, along with the upcoming FX-57! It all ties in with the fact that FX-53's PIB cooler would have sufficed for FX-55, but with AMD well on their way into developing desktop X2 and FX-57 at the time (both on 90nm and with the same TDP figures), they rolled out the PIB cooler for X2 and FX-57 early, with FX-55.
AMD were happy to weather the then speculation that the new cooler for FX-55, as it is with heatpipe technology, indicated that AMD were suffering somewhat spiralling heat outputs as they increased core frequencies of their products. In reality, it was them rolling out a cooler for a wide range of future products, early. Indeed, our testing was performed with the current FX-55 PIB cooler at all times.
That also has ramifications for third party cooling solutions that can also hangle FX-55. Something like the Akasa Evo33, which I personally use on the system I'm using to type this, which is powered by Athlon FX-55, is 99.9% (we can't confirm absolutely without an official statement from Akasa themselves) likely to cool the upcoming X2 processors and Athlon FX-57 without any problems whatsoever.
So for users with similar cooling solutions with the ability to cope with an FX-55's heat output (around 100W @ 2.6GHz, 1MiB L2 at 1.50V Vcore), you won't need a new cooler for an X2 processor.
Vcore for the new X2 range, as you'll see shortly, is 1.40V. All Socket 939 mainboards that support Cool 'n' Quiet, can support that default Vcore setting without any issue, since it's a transitional VID (voltage ID) for a massive range of current Socket 939 processors.
To sum it all up
I've put a lot of words down on the past 4 pages, some of which won't be of interest to all but the keenest technologists in our audience. So to sum up Athlon 64 X2 simply, here it is in a nutshell:It's two current Athlon 64 1MiB (Athlon FX/Opteron) cores, on 90nm, on the same die, sharing an SRI (system request interface) which means a shared memory controller and HyperTransport connection, with thermals handled by FX-55's retail cooler, which will drop into the vast majority of mainboards and work correctly, with nothing but a BIOS update.
With all that said, it's finally time to have a look at performance and the future of multi-threading software on the common desktop.
