Fedora 15 x64 stunning performance (vs Win7).

[Konstantin Svist]

On 01/06/2012 04:35 PM, Quicksort wrote:
> Hardware platform: Dell Studio XPS, Core i7 950, 8Mb L3 Cache.
> Operating systems: Fedora 15 x64 / Windows 7 x64 Ultimate
>
> Hi everybody,
>
> I have developed a sorting/searching library written in assembly
> language. As long as one stays in the L1 Cache (in place physical sorts)
> speeds are identical, but when the proportion of L1 cache misses
> is hign (sorts by reference which return an ordering vector as APL
> sorts do) Fedora dramatically outperforms Win7.
> This performance gap is stunning but consistent and I am not overdoing
> it. Something weird occurs when one leaves the L1 cache. As one remains
> in the L3 cache (my Core i7 950 has a 8Mb cache) the performance penalty
> is about 33%, with mixed L3 cache/main memory accesses it grows to
> 50%/60% ! I wish some x64 Linux kernel developer could enlighten me. The
> assembly code is exactly the same in both cases(except or course for
> calls to APIs being replaced with Linux system calls), JWASM assembler
> being used. No disk swapping, large/huge pages, or virtual machine
> involved and my test program is a plain application run from the command
> line.
>
> Any thoughts?
>
> Quicksort
>
>
>

You would probably have much better luck posting this question to LKML - 
that's where most kernel developers lurk.
  http://vger.kernel.org/vger-lists.html#linux-kernel

HTH