[SunRescue] SCSI vs IDE in a single user U10

[Christopher Byrne]

In case anyone is wondering whether the switch from IDE to SCSI is worth it
in a U10, all I can say is try it and see.

I finally recieved my Ultra 10 the other day, three weeks after I payed for
it (god I hate shipping naything around the holidays)and set it up. The
system was unopened, new in the box, but almost three years old.

Just an aside on how I got this system. A company had bought a lot of them,
then went out of business. Another company recently purchased their assets
in a bankruptcy auction, and sold me the U10. If you can get in on a deal
like this it's a great way to get high quality equipment at a reasonable
price.

Anyway being almost three years old it's an UltraSPARC-IIi 300, with 128megs
of RAM, and a 4.3gig seagate medalist drive.

I admit that the medalist isn't exactly the paragon of IDE devices thse
days, but from my perspective the I/O performance of the IDE subsystem was
pretty crappy. The solaris 8 actually took longer on the U10 than it had on
my U2 with fast/wide SCSI-2 drives and a 6x cd-rom. Then I did some routine
disk intensive tasks with the system like compiling some large programs, and
reviewing logs etc... and I was really unimpressed. The CPU had no problem
keeping up with everything, but the I/O was just REALLY REALLY slow. My disk
perfmeter was continually pegged while the CPU ideledat 1 or 2% waiting for
data.

The first thing I did was try replacing the medalist with a nearly new 7200
rpm Western Digital expert UDMA 66 drive I had lying around. That definitley
improved things a bit, but not so much as to make you jump up and shout
halleluhia if you know what I mean.

I was planning on switching over to a dual 36 gig Ultra 160 setup in the
near future anyway, but I didn't happen to have all the pieces together yet,
so I popped in the cheapass symbios controller card I had lying around (it
worked out of the box) and tossed on a 4 gig barracuda and plextor 8X
CD-ROM, and I was smoking.

These are like five year old drives and a majorly cheezy card, and anything
I was doing that required more than trivial disk access was 30% or more
faster.

Now I admit that my disk access patterns are far from typical in that I do a
lot of disk intensive multi tasking, but the performance difference was
notable even during regular tasks like web surfing and email. Any time I had
to save or open a large file there was a clearly noticable increase in
performance.

The only problem I've had so far is that whenever I try and run my SunPCI-II
I get segmentation faults, but I think that's a driver issue not a problem
with the drives.

Anyway just my humble opinion

Chris Byrne
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