On Mon, 24 Jan 2000 [EMAIL PROTECTED] wrote:
> Paul> That probably says more about Raptor- assuming you've done the usual
> Paul> Solaris tuning tricks. That or you're at saturation point for your
> Paul> outbound link (or buffers) or you're colliding trying to get to the Sun.
> Paul> U10's have a PCI bus though :(
>
> Why the frown? PCI is faster that SBUS. That's one of many reasons Sun
> switched to PCI.
Sun switched to PCI for economic reasons, raising the clock on SBUS would
have continued to produce a superior bus. PCI transfer rates on a 66MHz
bus are higher, that doesn't make the system faster. The 8MHz difference
on a normal PCI bus probably isn't significant, but I've not seen
benchmarks.
SBUS has better latency characteristics, better mastering, and the PCI
spec didn't even address arbitration fully until v 2.1. I typically used
to buy Sun Ultra2's as gateway machines where I'd shove QFE cards in the
SBUS slots and do a lot of internetwork firewalling. SBUS seemed to do
that job a lot better than PCI.
For SCSI where the card is a bus master, sure, PCI 2.x is
significantly better for data transfer rates than SBUS throw in the
onboard hme port, and you're still ahead. For a machine with 9 fast
ethernet ports (2 QFE cards and one hme0) I don't think PCI is going to do
as well.
FWIW, U10's only have a 32-bit 33MHz PCI bus, so the transfer rates
aren't going to be as good as a high-end PC.
Paul
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Paul D. Robertson "My statements in this message are personal opinions
[EMAIL PROTECTED] which may have no basis whatsoever in fact."
PSB#9280
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