The first bit of newsfrom the surest sourceis that the 940-pin versions of the Athlon 64 will indeed support dual channels of DDR400 memory, but they will require registered DIMMs. Obviously, the inability to use unbuffered memory is rather uncommon in desktop products, but not in servers and workstations. As you know, the original Athlon 64 chips were slated to have a single-channel memory configuration, and it seems the decision to go with dual memory channels on some Athlon 64 products came fairly recently. Obviously, notes our source, "the most cost effective way to get an Athlon 64 with a DC memory bus is to cripple the Opteron." AMD seems to be preparing to sell an Opteron rebadgedand perhaps slightly crippledas a high-end Athlon 64.
Not that there's anything wrong with that.
To that end, others have informed us that the reason for the 940-pin socket on initial dual-channel versions of the Athlon 64 is so AMD can take advantage of the existing Opteron infrastructurenamely, nForce3 Pro boards like the Asus SK8N. This explanation jibes with a late decision to go dual channel. Once the motherboard infrastructure is in place, the Athlon 64 will move over to the 939-pin socket to restore the physical product differentiation between Opteron and Athlon 64, as we've suggested before.
As for the Athlon 64 lineup, we hear there will be three versions, and all three will support DDR400 memory. At launch, there will be the high-end, dual-channel, 940-pin version of the chip, which will pack 1MB of L2 cache (just like an Opteronshock!). There will also be the single-channel, 754-pin version with 1MB of L2 cache. Finally, a 754-pin variant with 256KB of L2 will supposedly arrive some time after the initial Athlon 64 launch.
Could this last chip have been intended as the new Duron? We have long expected AMD to position the older Athlon XP as a budget solution once the Athlon 64 arrived, but then we expected Athlon 64 to arrive much sooner than it haserr, will. AMD's latest roadmap shows the Barton core Athlon XP's lifeline extending into the second half of 2004 "as market requires", but I expect AMD will want to push 64-bit computing across its product line once the Hammer products arrive in force. The guys at the Inq are noting that volumes of the 754-pin Athlon 64 chips are projected to decline precipitously in the second quarter of '04, so perhaps only this cheaper 754-pin variant will survive for long.
We are also hearing optimistic things about the prospects for AMD64 versions of Windows. It seems Windows Server 2003 may go 64 bits at the Athlon 64's introduction, with a 64-bit version of WinXP following before year's end.
Obviously, if all of these things are true, AMD is really scrapping to give the Athlon 64 what it needs to succeed in the big, bad world, even if things have to get a little messy.