Kernel Support for Dual Core x86-64?
Hi all-
My company is looking to build a cluster of Linux machines to run an in-house compute-intensive application. We're strongly considering dual-processor, dual-core x86-64 systems for cost reasons (shared hardware, less rack space). I have a few questions, and despite extensive googling, haven't been able to find satisfactory answers.
1. Can a dual core chip run two os-level *processes* simultaneously or only two threads from the same process? Our processes (written in Python, with parts in C) are completely independent of each other.
2. What sort of speed up relative to a dual processor, single core system could I expect to gain? I realize this is highly application dependent and I'm not looking for any hard figures. I just want to get a rough idea to see if the additional cost is worth it.
3. Any suggestions on compiler version? We're currently using GCC-3.3.6 on our 32 bit boxes.
Thanks in advance!
Signature · 3 lines
Peter Fein [email protected] 773-575-0694 Basically, if you're not a utopianist, you're a schmuck. -J. Feldman
Robert M. Hyatt, Ph.D. Computer and Information Sciences [email protected] University of Alabama at Birmingham (205) 934-2213 136A Campbell Hall (205) 934-5473 FAX Birmingham, AL 35294-1170
Quoted 8 lines · Peter Fein
Hi all-
My company is looking to build a cluster of Linux machines to run an in-house compute-intensive application. We're strongly considering dual-processor, dual-core x86-64 systems for cost reasons (shared hardware, less rack space). I have a few questions, and despite extensive googling, haven't been able to find satisfactory answers.
Quoted 4 lines
1. Can a dual core chip run two os-level *processes* simultaneously or only two threads from the same process? Our processes (written in Python, with parts in C) are completely independent of each other.
yes. A dual-core is two separate processors, on a single NUMA "node".
You can create two processes any way you want, from threads, to fork() to simply typings a&; b&, and the two processes will run on the two cpus just fine. I've run on a quad 875 system at AMD, and the box appears to have 8 cpus since each processor is dual-core. It runs like a bat out of Egypt also...
Quoted 5 lines
2. What sort of speed up relative to a dual processor, single core system could I expect to gain? I realize this is highly application dependent and I'm not looking for any hard figures. I just want to get a rough idea to see if the additional cost is worth it.
technically it is 2x faster. practically it depends on the application. My chess program runs at 2x the nodes per second, but the actual speedup is around 1.7-1.8X, due to internal search issues that have nothing to do with the dual-core. In fact, If I run on a dual-core I get about 1.7-1.8X, if I run on a dual-processor single-core opteron box (say 2 850's or whatever) I get 1.7-1.8X speedup. So I can barely tell the difference.
Quoted 3 lines
3. Any suggestions on compiler version? We're currently using GCC-3.3.6 on our 32 bit boxes.
I use SuSe on opterons as does AMD on the ones they let me test on. gcc 3.3 is plenty good enough...
Quoted 12 lines
Thanks in advance!
Signature · 8 lines
Peter Fein [email protected] 773-575-0694 Basically, if you're not a utopianist, you're a schmuck. -J. Feldman - To unsubscribe from this list: send the line "unsubscribe linux-smp" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html