Date: Sun, 10 Aug 1997 22:48:23 -0700 From: David Greenman <dg@root.com> To: Mike Haertel <mike@ducky.net> Cc: freebsd-hackers@FreeBSD.ORG, freebsd-hardware@FreeBSD.ORG Subject: Re: question about "ed" driver performance on ASUS SP3G & 486DX4/100 Message-ID: <199708110548.WAA09160@implode.root.com> In-Reply-To: Your message of "Sun, 10 Aug 1997 22:34:09 PDT." <199708110534.WAA03574@ducky.net>
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>>that FreeBSD supports. The raw access speed to the shared memory should >>be about 4MB/second - plenty fast enough to keep up with 10Mbps ethernet. > >Hmm... this inspired me to write a small benchmark. ... >On the 486 box, it takes about 15.5 seconds. On the Pentium box >(which worked for the NFS install) it takes about 14.5 seconds. > >Either of these is just slightly faster than 1 MB/sec and nowhere >near the claimed 4 MB/sec. Perhaps my board is pessimal and the >Pentium box, being just a hair faster, is fast enough to keep up? My 4MB/second number comes from doing a similar test in the device driver using bcopy at system startup. I don't know why your results are so slow, but I do recall seeing unusually low performance numbers from a P6 system that I once tested - I seem to recall they were about half speed or so, but I didn't investigate further. Just for kicks, you might try doing 16 bit copies rather than 32bit copies and see if your results are affected. -DG David Greenman Core-team/Principal Architect, The FreeBSD Project
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