Re: filesystem and x86 vs. x86_64 benchmarking...
"Dale E. Martin" <dale@the-martins.org> writes:
>> > not a bug. It would be interesting to know if you need double the memory
>> > for comparable (slightly improved?) performance for C++ compilation in
>> > x86_64. I hadn't really considered that. Hopefully it's a bug ;-)
>>
>> Every pointer is double the size and you have a lot of those in
>> gcc. On top of that you get more registers, more opcodes, more
>> inlining, ...
>
> Well, if it really takes twice the memory to get a few percent speed
> increase, I'd like to know. Compilation isn't the only interesting test,
> but it _is_ interesting.
Assume it takes at least twice. It's more like 4 times what you might
be used to. Some of that could just be the newer gcc/g++ version than
what I'm used to though.
But hey, compile once, run many times. And most things Debian compiles
for you.
>> 64bit userspace yes. But comparing 32/64 bit kernel with 32bit
>> userspace doesn't show a winner on your tests yet. You can#t realy
>> decide what kernel to use going by those tests.
>
> I don't have enough memory to run 64 bit userspace, I think we agree
> there. There is a clear speedup running a 64/32 setup over 32/32 using
> xfs, right? So why might 32/32 be better? Sorry to be dense.
How much memory do you actualy have? If you compile a lot I wouldn't
recommend anything below 1Gb.
MfG
Goswin
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