> 11GB DiamondMAX? That is probably the 2880 seris...a 5400rpm drive.
You're right, this is a 5,400 rpm drive - even more impressive.
> Now if Bonnie was an application that accomplished meaningful work, this
> could be useful. Since it doesn't, it just shows the speed of single
> read/write stream. Since it buffered through the OS, the first 240MB
> or so are written instantly to memory, so you aren't even getting a
> meaningful disk perf result either.
I posted Bonnie results because bonnie has become a widely accepted disk
performance benchmark. In the absence of an easy to run, widely
accepted alternative which performs something you would accept as real
work, readers can use the bonnie results for what they're worth. They
address, among other things, the myth that IDE subsystems extract a
large CPU-overhead penalty vi a vis SCSI. The write results aren't
meaningless, they just have to be interpreted in the context of the
system info I provided.
> I disagree. SCSI advantages:
>
> - Higher drive quality. EIDE drives are built cheap, just because that is
> what the market buys. Compare the listed MTBF for a Maxtor Diamond MAX to
> the list MTBF for a Seagate Barracuda 4LP/XL. In fact, it doesn't seem
> that Maxtor publishes MTBF figures...
>
> - Heavy IO. SCSI can have multiple outstanding IO request per bus and per
> drive. Most SCSI disks can have to 64 outstanding IO requests. This
> allow the host to use overlapping IO to improve performance, and it allows
> the drive to re-order requests for faster response. EIDE allows one
> outstanding request per channel.
This is all true. However, if you don't have much money, then IDE
delivers good performance at a very attractive price. We have not found
that the apparent advantages of tagged queuing have any real effect with
typical workstation configurations and workloads. As I said before, for
systems with few disks - say two, one for each motherboard IDE channel -
it's unlikely that you'll see much performance advantage from SCSI.
High spindle speeds, effective caches, and good drivers make IDE a good
low cost option for workstation storage.
- C
