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Re: hardware quote comments?

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. 

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