On Thu, 26 Sep 2002 21:14, Mike Silbersack wrote: > On Thu, 26 Sep 2002, Sean Farley wrote: > > > I just do not understand how a 5400 RPM UDMA 33 drive can beat a > > 7200 RPM UDMA 133 drive by 33% on sequential output blocks. > > Rumor has it that newer drives cannot write a single sector at a time, > and instead must read a whole cluster of sectors, add in the new > sector, and write back the whole cluster. That behavior sounds like > it would hurt sequentual performance substantially, as it would become > a lot of read-modify-write operations.
That is interesting. I had not heard of that issue, even as a rumor, before. I see this hurting byte writes, but block writes may not be hurt by it. > > > Does the drive support tagged queueing? That should give you the > > > benefits of write caching with a little bit more safety. > > > > I thought only IBM had IDE drives which supported tags. No. The > > specs do not mention tags. > > Hm, I thought other vendors had started to support them, I guess they > decided not to. :| I think there are a few Maxtor SCSI drives with it, but I could not find mention on their site with regards to any IDE drives. It would be nice assuming it was done correctly. > I have no idea on what BIOS settings would be optimal. I doubt that > they'll make a real performance difference. None as far as I can see. You would not happen to have a non-RAID, UDMA100+, non-VIA system that you could run bonnie++ (-s256) on? It would at least show to me if my system is really all that far from the norm. Sean ----------------------- [EMAIL PROTECTED] To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-hackers" in the body of the message
