Joe Landman wrote: > Memtest and fellow travelers access memory in a very regular manner. > Which is unlike the way most programs access memory.
Hmm, I see what you mean (although in my code I can often go through memory in exactly the same "regular" manner). If the memory tester doesn't specifically disable CPU cache (to force direct write through and read through) then it's going to be moving lines of memory at a time, which actually doesn't load the non-cache memory very much. For the purposes of memory testing, beyond just looking for an overtly bad memory location, it would probably make more sense to go "the other way" through memory, forcing as many cache misses as possible. That would result in fewer passes per unit time for the testing software, but each test is more likely to cause a problem, since the memory is busier. I'll ask the memtest86+ folks which way they go about it. If they are going straight through memory that might explain some of the differences that have been reported here. Regards, David Mathog [EMAIL PROTECTED] Manager, Sequence Analysis Facility, Biology Division, Caltech _______________________________________________ Beowulf mailing list, [email protected] To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
