[ILUG] bus bandwidth...
drjolt+ilug at redbrick.dcu.ie
Thu Sep 23 12:40:48 IST 1999
Quoting <19990923121025.C32752 at tuatha.org>
by "John P . Looney" <valen at tuatha.org>:
> PCI is supposed to be 32bit 33Mhz. That's 133 MB/sec, theoretical
> max. SBUS (Sun's pre-pci bus) is 25MB/sec, proven.
Really? Proven by what, exactly? Sun quote the SBUS bandwidth at
100MB/sec for 32-bit SBUS, 200MB/sec for 64-bit SBUS, theoretical
maxima, of course.
Check out their PCI:SBUS comparison at
> The Sun Enterprise 10000, which is a modified cray machine uses
> SBus. I've seen these machines with loads of gigabit network cards,
> fiberchannel cards etc. plugged into them. What's the point, if you
> only get 25 MB/sec into the machine ?
There wouldn't be, if that were true ;)
> Something is really odd here. Is SBus really that bad, or does PCI
> perform a lot worse under real conditions ?
> OK, I know that Sun are shipping machines with 64bit 66Mhz PCI, but
> the big iron machines aren't going to see that bus for two years or
Actually, you can get a PCI module for your 10000, if you want.
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