jrelliottoh said:
Wisecracker - Thanks very much. Did you read my reply/clarification of the meaning of "core?" Is your meaning the same as mine? Am I right to understand that 12-core processors are available? Is AMD the only mfr? I didn't find anything like that from Intel. Usually, there are mitigating circumstances when AMD and Intel are out of sync. E.g. A 12-core AMD will barely keep pace with an Intel 6-core because... of some technical reason that I don't know at this time.
I searched NewEgg for "AMD Dual Socket G34" and found Tyan and Asus (supermicro was 3x more expensive). I have had trouble with both Tyan and Asus in the past. The Asus seems to work best but capacitors melt after 2-3 years. Can you comment on your experience with these (or other) MB mfr's?
OS - issues: I think XP is limited to 4 cores? Will windows7 manage 16 cores efficiently? Is it necessary to transition to Linux? Is one version of Linux better than another? We are currently favoring Ubuntu and Fedora.
Not sure I can answer all this
There are AMD CPUs with 12 cores.
Quote:
I think of a core as a physical cpu, equivalent to the old style of dual processor MBs. Taking the number of threads beyond the number of "physical cores" will lead to reduced performance on a per thread basis
See above. A single physical CPU may have multiple cores in one socket. By adding a second socket, or *2P*, you may effectively double that number of cores.
More physical cores = more threads running in parallel. Intel provides a 'virtual' core through hyperthreading. Actual cores generally perform at a higher level than virtual cores. You are the one who knows the level of actual parallelization as opposed to simply multiple instances. If it is your software and your instructions you make the 'calls'. How your hardware handles it many times is mostly up to you. I suspect a "Nix is the way to go for your OS for a number of reasons, but how well may your software perform with NUMA?
Each CPU socket has a DIMM bank. You want all those 12 cores (threads) making local calls. You may utilize NUMA-friendly coding in 'Nix mem policy but we don't know the size or how you handle or code data sets. There is stuff that you need to consider. Is it distributable across 2 or more computers each with multiple sockets running multiple cores?
NUMA issues can make any hardware run like a dawg but theoretically with *4P* you could have 48 threads each with 2GB+ of local memory. Good luck with that. If optimized code for that grew on trees we would all own orchards.
And I suspect parts of the new instruction sets will look and perform a lot different from that with APU processing and the VEX codng.
I don't have a problem with Tyan - I build to their specs and don't screw around with marginal components.
You would need XP Pro to recognize the second CPU socket - same with Win7. Some enterprise software is licensed by socket.