Date: Sun, 7 Apr 1996 17:31:25 +0200 (MET DST) From: Andreas Klemm <andreas@knobel.gun.de> To: Satoshi Asami <asami@cs.berkeley.edu> Cc: current@freebsd.org Subject: Re: fast memory copy for large data sizes Message-ID: <Pine.BSF.3.92.960407172757.295A-100000@knobel.gun.de> In-Reply-To: <199604052039.MAA25813@silvia.HIP.Berkeley.EDU>
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On Fri, 5 Apr 1996, Satoshi Asami wrote:
> Marc, thanks for running the test.
>
> * > sh runtests
> * > size libc ours
> * > 32 7.629395 MB/s 7.629395 MB/s
> * > 64 12.207031 MB/s 4.695012 MB/s
> * [...]
> * > 2097152 12.164192 MB/s 7.725020 MB/s
> * > 4194304 12.290410 MB/s 7.719504 MB/s
> * > mrami[~/bcopy]$
> *
> * these tests SEEM to be indicating that the bcopy in libc
> * is already better! or am I misreading something?
>
> No, it only shows the libc version is faster on a 486. We expected
> that, as the FP unit on a 486 is much slower than a Pentium. (Even a
> straight int -> FP conversion takes a lot of time I guess.)
>
> Any other Pentium owners? :)
P90 overclocked to 100 MHz, 32MB 60ns PS/2 RAM, ASUS P55TP4XE
mainboard, 256k sync. burst cache, -current, of course.
Kernel was compiled with the pgcc -O6 -fomit-frame-pointer,
the rest (that couldn't be compiled with a cc -m486 -O2
- -fomit-frame-pointer.
size libc ours
32 30.517578 MB/s 15.258789 MB/s
64 61.035156 MB/s 20.345052 MB/s
128 40.690104 MB/s 30.517578 MB/s
256 40.690104 MB/s 34.877232 MB/s
512 40.690104 MB/s 40.690104 MB/s
1024 39.062500 MB/s 40.690104 MB/s
2048 39.062500 MB/s 42.459239 MB/s
4096 39.062500 MB/s 43.402778 MB/s
8192 39.062500 MB/s 43.890449 MB/s
16384 39.062500 MB/s 44.263456 MB/s
32768 39.111389 MB/s 44.452347 MB/s
65536 39.135880 MB/s 44.547398 MB/s
131072 39.123631 MB/s 44.563280 MB/s
262144 39.135880 MB/s 44.618954 MB/s
524288 39.138943 MB/s 44.622936 MB/s
1048576 39.143539 MB/s 44.644850 MB/s
2097152 39.131285 MB/s 44.652824 MB/s
4194304 39.128989 MB/s 44.639370 MB/s
Andreas ///
- --
andreas@knobel.gun.de /\/\___ Wiechers & Partner Datentechnik GmbH
Andreas Klemm ___/\/\/ $$ Support Unix - aklemm@wup.de $$
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