On Mon, Feb 25, 2002 at 03:11:43PM -0800, Alvin Oga wrote:
>
> hi ya
>
> comparing ide vs scsi..... an age old problem... ??
>
> i say....in my opinion..
> you cannot compare an 5400rpm ata-133 ide against a 15krpm scsi-3 u160..
> ( well at least definitly not a 5400 rpm 10GB against a 15K rpm 80GB scsi3)
Sure you can, but you cannot extrapolate that one comparison to all
SCSI/IDE comparisons.
> - if you do compare ... use tiobench or bonnie...
> for real life performance differences with real data ??
Which even then may not be an accurate representation of the real
live usage.
> - not raw basic numbers comparson of "feature/characteristics"
> - raw rpm speed by itself doesnt matter ...
> - 7200rpm ide disks runs hotter than 5400 rpm ide disks :-)
Oh yeah they do, but fans are cheap, and (for my application) noise
is irrelevant. If the machines are running too hot, I yell at
facilities to pump more cold air into the cage.
> - ata-33 ( 33MB/sec) vs scsi-3 (20MB/sec ) comparason doesnt matter ??
> - its comparing different "numbers" ...
> ( but actual data transfer of the same test program is a
It also matters what kinds of transfers you are doing. Streaming a
2 GB media file into memory (for editing) or out onto the network
is a lot different that making 2GB of changes to a 130GB database.
> - if one disk is spinning at 5400 rpm... and the other is spinning at 15k
> rpm ... guess which one will seek faster on the same cylinder ??
All else being equal, the faster. Of course, if you're comparing a
120GB 5400 RPM IDE against a 9GB 15K RPM SCSI drive, your *real
life* seek times might be faster on the bigger drive (head latency,
seek distances etc.).
> - transfer speeds are comparable ???
In the real world? Probably. YAMV.
> -- btw IBM 40GB and 60GB are pure junk !!! all the disks that failed
> are IBM drives...
We've been killing the 75GB Deskstars like flies in a bug zapper.
10 coming in off RMA this week, 10 more next week etc...
> -- hott scsi disks are also sitting on my desk... higher death rates
> of scsi disks vs ide disks as a ratio of number of numbers in use...
I've had the opposite experience recently.
(25% failure rate after a month on Maxtor 120G (sample size 4),
40-50% failure rate on the Deskstars after about 6 months use
(although not until they were put into production on DB machines,
none had failed previously).
About 5% or less failure rate on the 9G IBM and Quantum drives that
have been in production for 18 months to 2 years (sample size
roughly 200). None of the 34G IBM SCSIs (sample size 20) have failed yet.
--
Share and Enjoy.
