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Cray Supercomputers to be Based on AMD Opterons
PsychicX writes "AMD and Cray have announced an agreement to base Cray supercomputers on AMD's Opteron line until the end of the decade, and to collaborate on Cray's 2006 proposal for Phase 3 of the federal government's DARPA HPCS (High Productivity Computing Systems) program. Cray already offers the XT3 and XD1 supercomputers based on Opteron."
Tera bought far more than a name when they bought us. They also bought a bunch of software and hardware people, many of whom (myself not included) have been with Cray Research (the original Cray) for many years. So, while it's certainly not the Cray of the mid-1980's, the tradition still goes back there, especially with the vector machines like the Cray X1/X1E and its impending follow-on.
Go Badgers! -- #include "std/disclaimer.h"
I've never completely understood this argument (yes, I admit, I'm heavily biased). If I want to build a skyscraper, I'm not going to use the "mass market" crane that puts up the roof of a residential house. I'm going to use a specialized crane that's meant for building skyscrapers.
That doesn't mean that there isn't a place for commodity hardware in supercomputing, but to say that there's no room for custom hardware either misses the point. The only thing "off the shelf" about an AMD based Cray is the AMD. The logic board, and, most importantly, the network that interconnects the processors is entirely custom. Not to mention the fact that Cray will still build some entirely custom processors...
By the way - this is hardly the first Cray based on a commodity processor. The T3E and T3D were both Alpha processors, yet nobody calls those machines "commodity".
Go Badgers! -- #include "std/disclaimer.h"
Close.
Craylink was designed at SGI, and renamed to craylink after they bought Cray. They introduced craylink in the origin2000, which they started selling half a year after buying cray, so I'm sure they couldn't have integrated any cray-designs into their product in that span.
After they sold Cray to Tera, SGI started calling the technology Numalink, and currently use it in their origin3, altix3, and altix4 product lines. They are on the 4th generation of the technology, which is 3.2GB/s per direction. The cray that was sold to Tera included the half-finished X1 system, which also uses numalink. It uses the older 1.6GBps/dir links, but uses 32 networks in parallel for a total of ~50GB/s/dir per node.
The Cray XT3 uses a newer network interconnect called seastar, which offers 3.8GBps/direction. This is probably what will be used in the X1's successor.
The Cray XD1, which your colleague bought, is a product cray acquired when they bought OctigaBay. They use an interconnect called the RappidArray switch, which provides 4GBps/direction of interconnect.
All of these interconnects are high-bandwidth and low latency. The XD1, is also very inexpensive for a cray, which is always nice.
No they won't! They have no reason to. The vector units that a cray uses aren't like altivec, sse, or other "bolt-on" vector units. The vector unit on a cray (or NEC) is a latency hiding mechanism. It's a method for forcing the programmer/compiler to structure the code such that the data loaded from memory is used a significant period of time after the load is initiated. This works pretty well on the HPC code that is used on crays, but not at all for the everyday server/workstation code that opterons run. Furthermore, to support that sort of vector unit, you need to have about eight times as much memory bandwidth as an opteron, which means many more pins on the socket, which are very expensive.
I think you're much more likely to see the cray vector processor retooled with lots of hypertransport connections, so it can use an opteron as its scalar unit, and use the same seastar routers that the xt3 uses. On the X1, the scalar unit already runs ahead of the vector unit, so I bet it's not all that important for the scalar unit to be on-die.