Re: Rob: Verne Tice's High Resolution Timing routines
Vincent wrote:
>
> Great News: I found a "patch" solution to time()'s performance issues!
> I feel so relieved now! 
>
> Not only does Verne's library offer a high resolution time(), but also
> out-performs
> Euphoria v2.5 time() and is even faster than v1.2 on DOS and about 25% faster
> on Windows. I made some minor optimizations (which sped up hrtime() even
> more),
> and added memory deallocation routines to his library. I couldn't test it on
> Linux or FreeBSD, but I imagine the performance would be much improved too.
>
> Not that you're is interested, but I thought I'd share the results. :
>
> Sequence operations:
> * v1.2 'EX.exe' has slightly faster slicing than v2.5 'EX.exe' w/ hrtime().
> * v2.5 'EX.exe' w/ hrtime() performs 2x faster appending than v1.2 'EX.exe'.
> * v2.5 'EX.exe' w/ hrtime() beats v1.2 'EX.exe' by a fair margin in all other
> sequence tests.
> * On Windows hrtime() is about 25% faster than regular time() on most
> benchmarks,
> but is still beaten slightly by v1.2 'EX.exe' in 3 out of 5 sequence tests
> (it's
> a close though, and the other 2 are faster).
>
> Old Sieve:
> * v2.5 'EX.exe' w/ hrtime() is ~1.622x faster than normal v2.5 time().
> * v2.5 'EX.exe' w/ hrtime() is about 5-10% faster than v1.2 time().
> * v2.5 'EXW.exe' w/ hrtime() is the same speed as normal v2.5 time().
>
> New Sieve:
> The newer sieve benchmark was designed better with very little reliance on
> time()
> in determinding results. Both time() and hrtime() perform equally well on both
> DOS
> & Windows; both of which are faster than v1.2 time().
>
>
> The problem is the library uses the RDTSC CPU instruction, which is only
> available
> in Pentium & K6 class CPUs and newer. So if you have a 386 or 486, your out
> of luck and would have stick with normal time().
>
> Another problem is if the CPU has dynamic clock frequency adjustment
> technology
> (speed-step, etc.), it would have to be disabled in the BIOS first; otherwise
> you could get unreliable timing results or worse.
>
> These issues will probably prevent you from ever implementing this sort of
> thing
> in the official Euphoria interpreters, but you should still mention this
> library
> in the time() comment paragraph, in the reference manual.
I haven't looked at his stuff in any detail,
but maybe there's a way of testing at start-up whether Verne's
routines can be used. If not, I would fall back to using the
normal time().
Regards,
Rob Craig
Rapid Deployment Software
http://www.RapidEuphoria.com
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