QuickPath v HyperTransport
You can see why Intel has been taking back market share in the server space with that kind of bandwidth, which is more than three times what its prior Xeon 5400 quad-core chips could deliver because of the technically inferior frontside bus. The QuickPath Interconnect, an homage to AMD's HyperTransport, has allowed Intel to take back some market share.
But it looks like AMD is going to get a turn to eat a few points of share with the Opteron 6100s on two socket systems thanks to a 50 GB/sec rating on the Stream test. The current Istanbul 2400 series chips deliver just north of 20 GB/sec of memory bandwidth on the stream test, which is pathetic compared to the Nehalem machines.
That 100 GB/sec of memory bandwidth in the forthcoming four-socket Opteron 6100 machine is one of the reasons why AMD decided not to do eight-socket configurations with these chips. "It is a lot of development work for a not very large market," says Fruehe, who reckons that there are only about 1,800 x64-based eight-socket servers sold worldwide each quarter and that the number is dwindling as four-socket boxes get more powerful.
"Intel is raving about having 15 different designs for its upcoming Nehalem EX machines, but how many is each vendor going to get out of those 1,800 units?" Fruehe says that the 8P boxes account for less than two-tenths of a percent of current shipments each quarter, and that while 4P boxes are only accounting for around 4 per cent, "even though it is a small space, AMD needs to be there."
The Opteron 6100s are set to ship at the end of the first quarter of next year, and were originally due in the second quarter. But the revamping of AMD's chip design, manufacturing, and testing processes after it screwed up the "Barcelona" quad-core Opteron launch in the fall of 2007 has allowed it to deliver three generations of Opterons since then earlier than planned. (Of course, a cynic might say that AMD is really just managing expectations and giving itself some buffers). "We have Magny-Cours samples out to our partners, and it is looking very healthy," says Fruehe.
The Opteron 6100 series chips are implemented using the same 45 nanometer processes that GlobalFoundries, AMD's wafer baker, used to make the Istanbul Opterons. The Opteron 6100s will come in standard thermal envelope parts (75 watts) as well as in Special Edition versions (slightly higher clock speeds at 95 watts) and Highly Efficient versions (slightly lower clocks and lower voltages at 55 watts). Clock speeds have not been divulged for the chips.