Comment Sub-optimal motherboard (Score 1) 650
The Opteron was intended to be used in multiprocessor configurations with a NUMA design, and functions optimally with processor-local memory and a NUMA-aware OS. This benchmark was done with a degenerate motherboard on which all of the system memory is attached to one of the processors. The other processor must access all system memory indirectly through its peer, and its integrated dual-channel DRAM controller is not utilized at all, halving the maximum memory bandwidth of the system.
Few mass-market dual Opteron boards available now support processor-local memory on both CPUs. Sadly, most vendors seem reluctant to discuss this rather important detail in their whitepapers and marketing material. I think Tyan's boards, specifically their K8W desktop board, does this correctly and is a good choice from this point of view, but costs upwards of $450.
Even with a better designed motherboard, this benchmarker used Windows XP, which is not NUMA-aware. More recent Server 2003 and Linux releases are NUMA-aware, and would have to have been used to take advantage. Such details have been shown to boost performance by 20% in different but more reputable benchmarks.
The Opteron's new memory architecture is arguably a larger advantage over previous generations than its 64-bit arithmetic and addressing modes. This is a feature that it does not share with the G5.
Few mass-market dual Opteron boards available now support processor-local memory on both CPUs. Sadly, most vendors seem reluctant to discuss this rather important detail in their whitepapers and marketing material. I think Tyan's boards, specifically their K8W desktop board, does this correctly and is a good choice from this point of view, but costs upwards of $450.
Even with a better designed motherboard, this benchmarker used Windows XP, which is not NUMA-aware. More recent Server 2003 and Linux releases are NUMA-aware, and would have to have been used to take advantage. Such details have been shown to boost performance by 20% in different but more reputable benchmarks.
The Opteron's new memory architecture is arguably a larger advantage over previous generations than its 64-bit arithmetic and addressing modes. This is a feature that it does not share with the G5.
