Nitro,
Here are benchmarks for my system so far:
Setup:
Dual AMD Opteron 242, Tyan Thunder K8W S2885 motherboard
1GB OCZ Tech PC3200 CL2 ECC registered meory (4 x 256MB, 2 per CPU)
Windows XP 64 Bit edition
Tested with SiSoftware Sandra 2004.10.9.133 SP2B (IA32, No AMD64 code)
config 1:
bank_interleave=auto node_interleave=auto, no NUMA detected by Sandra
(this mode interleaves memory addresses between CPUs on a per-page basis in order to normalize latencies)
Mem bandwidth 4260/4128 MB/sec
Cache & Mem Combined index 10250MB/sec Speed Factor 7.5
config 2:
bank_interleave=auto node_interleave=disabled, NUMA detected by Sandra
(memory addresses start with CPU0's memory, then CPU1's)
Mem Bandwidth 6034/6043 MB/sec
Cache & Mem Combined index 10788MB/sec Speed Factor 6.4
These numbers are fairly consistent between runs. Did your inconsistency between runs ever resolve itself when you added two more processors?
Quote from nitro:
Clearly the Opterons had a much higher memory bandwidth test, but it got creamed on the mem/cache test against the Xeons. Why is the Opteron mem/cache test so much worse than the Xeons, especially seeing that the Opterons clearly have a much higher results on the Mem Bandwidth test
It seems a low speed factor is desireable:
âSpeed Factor: is a figure representing the speed differential between
the CPU's cache and memory. The value is the ratio of the fastest
cache (i.e. L1) bandwidth to the main memory bandwidth. (Lower is
better, i.e. the memory is not very much slower than CPU's cache)â
But now why is my memory bandwidth test giving 6 GB/sec while the combined index is 10 GB/sec?
My memory bandwidth numbers should be around 10GB like yours. Maybe the Opteron 242s are a bottleneck at 1.6GHz. Most of the published benchmarks use 250s. Maybe my BIOS memory settings are sub optimal. Next time I have a chance to reboot Iâll write down my bios settings and post them to compare with yours. I haven't had much time to benchmark all combinations.
I use Remote Desktop from anywhere in the world that has a connection to the Internet and it is as if I am sitting in front of the machine at the colocation facility.
Are your systems operating entirely on collocated servers? Can you trade unattended? I thought you were once opposed to this.