The 3% Wonder
I’m getting some emails which indicate some ignorance of what x86-64 entails.
From a circuitry standpoint, x86-64 is, and never has been a big deal.
All x86-64 processors have is a little extra circuitry to handle 64-bit instructions. This only adds 2-3% to die space. If you don’t believe me, let AMD tell you that (page 15).
That doesn’t mean it’s useless, quite the contrary. x86-64 circuitry gives a tremendous amount of bang for the silicon buck.
Taking out x86-64 from Hammer processors makes no sense from a cost-cutting or die-size perspective. Hammer’s memory controller chews up much more die space than that.
The only plausible reason to rip-out/deactivate x86-64 circuitry from the already greatly gelded mini-Hammer is not to save money making those, but to make more money on those processors that do have it.
The idea that people will be shaking in their boots running 32-bit applications on a 64-bit capable CPU is just silly, especially around here.
Trying to get a big premium (as in hundreds of dollars) for that extra 3-4 mm may prove to be just as silly.
This approach may make some sense at the very bottom of the totem pole, down around the Duron level, but otherwise, it looks like a very short-sighted racket.
AMD is not just trying to get a new processor line going. It is also trying to get x86-64 going as a new hardware standard. To do that, you need software, and to get people to port software over, you need a user base, as big a user base as you can get as quickly as possible.
It takes time to get software companies to be convinced of that, and more time for them to do it. That’s true even for Intel, which is as sure a bet as you get in this business. You didn’t see tons of SSE2 software around the day the PIV came out; it came over time.
Companies are going to need a lot more convincing to go x86-64, and the best way to do that is to show those companies customers. Lots of them.
You don’t do that by making x86-64 an elite chip. You do that, you don’t have a mainstream processor, you have an Alpha. True, you’ll get a few workstation-type programs converted quickly, but how much else?