Re: SCSI vs. IDE performance test

"Rick Gigger" <rick(at)alpinenetworking(dot)com> writes:
>> "we have no portable means of expressing that exact constraint to the
>> kernel"
> Does this mean that specific operating systems have a better way of dealing
> with this? Which ones and how?

I'm not aware of any that offer a way of expressing "write these
particular blocks before those particular blocks". It doesn't seem like
it would require rocket scientists to devise such an API, but no one's
got round to it yet. Part of the problem is that the issue would have
to be approached at multiple levels: there is no point in offering an
OS-level API for this when the hardware underlying the bus-level API
(IDE) is doing its level best to sabotage the entire semantics.

> Do serial ATA drives suffer from the same issue?

Um, not an expert, but I think ATA is the same as IDE except for bus
width and transfer rate. If either one allows for multiple concurrent
read/write transactions I'll be very surprised.

regards, tom lane