A64’s at 3GHz On Air? . . .

The Inquirer mentioned the other day that AMD will be launching new A64s.

This was based on an Asrock BIOS update, and the same change can be found for other mobos, Epox being one.

Currently, all A64 processors have an OPN like this: ADA3200DAA4Bx. These new processors will have codes that will be like this: ADA3200DKA4Cx.

Is this an improvement? Maybe, maybe not.

Until fairly recently, 90nm 512K A64s were what is called a Venice chip with an E3 stepping. They were identifiable by a code like ADA3200DAA4BP on an OEM chip (the boxed version would read something like ADA3200BPBOX). BOX).

Recently, an E6 stepping was introduced. They were identifiable by a code like ADA3000DAA4BW on an OEM chip (the boxed version would read something like ADA3000BWBOX).

So far, the consensus on the E6 chips is that they are no better or worse than the E3s for overclocking. They certainly aren’t better like the Opterons.

The new A64s are supposed to be both E4 and E6 stepping chippings. Another E, you see. What’s an E4?

E4s stepping chips are what powers those overperforming Opterons (as well as FXs and 1Mb A64s). They can be identified by a “BN” suffix on the chip/box.

Before you jump for joy, if you look at the BIOS update page, you see something odd:

ADA3700DKA5CF – Athlon 64 3700+, 939pin, Rev. E6
ADA4000DKA5CF – Athlon 64 4000+, 939pin, Rev. E6
ADA3200DKA4CG – Athlon 64 3200+, 939pin, Rev. E4
ADA3500DKA4CG – Athlon 64 3500+, 939pin, Rev. E4

As of the moment, E4 definitely looks better than E6 for overclockability. E4 up to now has also been restricted to 1Mb cache models only.

It is the low-end chips that are getting the E4 stepping, while the high-end chips are getting the E6 stepping, which is the opposite of what you’d expect if speed were the only criteria.

Of course, speed isn’t everything. Using all usable cores/facilities is.

What I think is happening is that at least some of these new E4s will be processors with some faulty cache memory, so half will be disabled. Maybe they’ll overclock great, maybe they won’t. In any event, AMD has put itself in a position where, at least officially, the lower-end A64s will cost more and offer less than the Opterons.

That’s a pretty odd way to do business.

You may well ask, well, what about the E6s? Well, there is another AMD CPU that is made using an E6 process (though a different one than the A64s). Those are the dual core processors. Perhaps in some way the faulty ones that come out will be cut down to single core level

I may be wrong, but that explanation fits all the facts.

Ed