"km b" <[EMAIL PROTECTED]> wrote: >> Where is the generalisation? I said "my own code", which is what I'm >> interested in. > >You're claiming that all 32-bit binaries are faster than 64-bit >binaries based on your specific experiments which is nothing but >generalization.
I made no claim about "all" binaries, and I claimed the exact opposite of what you say I claimed for my own binaries: I said the 32-bit binaries are 50% slower than the 64-bit binaries. (Eg, running time 25 secs for 64-bit, 38 secs for 32-bit.) >> They are all 64-bit OSs (Linux or Solaris), but a 32-bit binary links >> with 32-bit libraries. I don't see why you think the cache usage >> would be worse for a 32-bit binary. > >Simple answer would be cache line size and how processor utilizes >cache for given virtual address. You would see this effect more if >you were just on the edge of thrashing the cache in 32-bit mode, >64-bit mode would completely thrash. You seem to be under the odd misconception that I'm claiming 32-bit is faster. For my code (and other scientific code), 32-bit is *slower*. And that can't be explained by thrashing cache -- as you rightly point out, a 64-bit binary would be *more* likely to suffer such problems, yet it's faster. Please read mail properly before shooting off angry replies. In fact I can believe that code that only uses 32-bit ints, but has large memory requirements, would perform worse in 64-bit mode. But the question is who cares about such code (indeed, how much such code even exists that's speed-critical). The sort of job that takes hours to run -- scientific, multimedia, etc -- would most certainly run better in 64-bit mode. Rahul
