Memory Tests
ScienceMark 2.0 is used to measure system memory bandwidth and system memory latency for the tested systems. Most of the time it crashed with HT enabled on the Paxville box, but if you persevere it'll run eventually, giving results in the right range. The results here will give you the first glimpse at what you'll see throughout testing, regardless of the test or benchmark.System Memory Access Latency
The on-chip memory controller of the Opteron was always going to have it come out the winner in this test. What's interesting is the Paxville system working better with HyperThreading turned off. Keep that in mind, since it'll be explained later.
System Memory Bandwidth
What this benchmark doesn't tell you is that the Opteron system has that bandwidth available per CPU in the system, because of NUMA (which the OS supports). The Paxville system, with its off-CPU, shared, memory controller, has that meagre bandwidth to share among 8 possible hardware threads, interleaved due to the system bus. Finally, with HT off the Paxville system posts a better result, precisely for that reason.
