Kernel Rebuild & Status... (fwd)

Jim Nance (jlnance@isscad.com)
Thu, 17 Aug 95 15:40:50 EDT


> Board:
> noname - 166Mhz - PCI 256kCache , 32Mb RAM.
> Rating: 75,000 drhystones (II) - same speed as a P90.
> Cost: =A3900 (incl cache) , about twice the price of a P90.
> !!!!
>
> I guess the real question is, where did all that speed go? The motherboard
> manual quotes 330,000 dhrystones on the 166Mhz Chip..... :-(

The original poster was nice enough to send me the source code for this
benchmark, and I ran it on our alpha here. I am not sure exactly what
the official name of this machine is, but the following is written on it:

AlphaStation 600 5/266

I ran the benchmarks using different compilers, and my purpose was to see how
gcc compared to the native DEC compilers. This was run under OSF/1 V3.2.
I would be happy to mail statically linked executables to anyone who wants
to see if the speed difference is as pronounced under Linux. The results
are shown below. Please note that the -migrate flag actually causes a
different compiler to be used.

Jim

Command: a.out 100000

Compiler Flags Dhry/Sec
cc -migrate -O5 -ansi_alias -ifo 705882.4
cc -migrate -O4 -ansi_alias -ifo 705882.4
cc -migrate -O 689655.2
cc -O4 618556.7
cc -O 517241.4
gcc -O 472440.9
gcc -O3 526315.8
gcc -O3 -fomit-frame-pointer 526315.8