On Fri, 18 Jul 2008, Al Hopper wrote: > If you look at the overall I/O throughput in Mb/Sec over the years and > compare it with the advances in server memory size or SPEC-int rates > over the years, the I/O throughput curve looks *almost* flat - as the > delta between the other two curves continues to widen. What is even > worse, is that to improve the I/O curve, especially in terms of I/O > Ops/Sec (IOPS) is very, very expensive. Flash drives - or even a
While I certainly agree with you regarding IOPS, I would not agree that I/O performance gains have been flat. Sequential I/O performance has been increasing over the years similar to memory performance. 220MB/second is a lot faster than 3MB/second. We are now in a situation where per-core CPU performance has stalled (actually retreated by 30%), RAM memory performance has almost stalled, and disk seek times have completely stalled. Solid-state devices will definitely help dramatically with IOPS (by eliminating the seek) but it seems that the vast majority of solid state devices will still be much slower at sequential write I/O than traditional hard drives. It is fully conceivable that in a couple of years, hard drives will be supporting 400MB/second with 4TB of storage each. As far as saving power goes, a recent study found that FLASH drives were consuming considerably more power than the hard drives they replaced. This study likely applies to laptop/desktop applications rather than server applications. Bob ====================================== Bob Friesenhahn [EMAIL PROTECTED], http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
