SUMMARY: PCI and Ultra10

From: Dave Wreski (
Date: Mon Jun 22 1998 - 20:44:42 CDT

Hi all. My original question was regarding the new Ultra10 machines
and the switch to PCI instead of the Sbus and SCSI. I understood IDE
is cheaper than SCSI, but couldn't understand how people could expect
to use those as servers. Apparently these are intended for workstations,
which I did not know.

Thanks very much to everyone for their help. Your time is very
appreciated. These are the best notes from the responses:

IDE are a lot cheaper than SCSI, and they were trying to come in at the
same price as a high end PC work station. The ultra 5's and
10's are meant as entry level high performing workstations.

SBUS runs at 25mhz with 64bits -- PCI runs at 33 or 66 mhz (or 100 soon)
at 64bits. Speed. Speed. Speed. So that makes PCI: Faster,
more in use than Suns proprietary SBUS, and a lot cheaper to make... :)
With UPA (lattice bus) it seems silly to have 25mhz SBUS cards on the system.

Also, Sun must write drivers for the PCI cards from a PC to work on a Sun.

The peak bandwidth available with 33MHz, 32 bit PCI should be
132 MB/sec. Of course, the PCI bus will be shared by different
peripherals, and there is bus control involved, not just data
transfer, so the effective BW available to disks will be less,
but unless you are using Ultra SCSI II(80MB/sec) it should be
too much of an issue.

I would recommend that you talk directly to an authorized SUN var and
get "official" answers to your questions.

Sun Ultra uses a 4500rpm EIDE Seagate Medalist hard drive which cost
less than a 7200rpm SCSI. Its a lot slower for many reseason but cost

Sun Ultra uses a 66mhz super-set of the PCI bus standard, and not all
manufacturers of PC PCI cards support this. So, no not all PC PCI cards
work in Ultras (actually not many).

Newmedia magazine just did a review of the Ultra10 (
Naturally, on any tests that where hd intensive, the 10 came in last.

Sun does not offer a SCSI option for these machines, except externally.

Even though Sun is moving aggressively to PCI, they do not offer a
PCI-based headless server (other than the 450), and their highest
performance chip (360Mhz/4mb cache) is not available in the Ultra-2
(only in the U60 graphics workstation).

I am less enthralled with the Ultra-5 even though it has a 270Mhz CPU
because the 256Kb memory cache (vs. 512Kb for the U10/U1, 2Mb for the
U2-300Mhz, 4Mb for the new U60-360Mhz) is too small for most serious
applications. Interestingly, our disk benchmarks were for the 1 U5
we test was twice as slow as U10's results. I can only assume this is
due to the smaller data cache because I think that that rest of the
architecture is the same.

For technical specs of Sun workstations, go to and Click
on the Products link.

Answers From:

O'Neal,Chris <>
wstuart <>
Parks Fields <>
(Saurabh Jang) <>
Benjamin Cline <>
Peter Polasek <>
Matthew Stier <>
Mark Sherman <>
Clive McAdam <>
Ian TCollins <>
Eric D. Pancer <>
(Matti Siltanen) <>
Don Lewis <>

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