Bob Friesenhahn wrote: > On Fri, 14 Nov 2008, Joerg Schilling wrote: >>> ------------ --- ------ >>> Disk RPM 3,600 10,000 x3 >> >> The best rate I did see in 1985 was 800 kB/s (w. linear reads) >> now I see 120 MB/s this is more than x100 ;-) > > Yes. And how that SSDs are entering the market, the disk RPM has > dropped down to zero. 10,000 --> 0. I am not sure how to interpret that.
I don't have a data rate for SSD's, but a hard limit is going to be the 3Gb/s SATA/SAS bus which is going to be around 300MB/s. I've no idea how close they come to this in practice. For IOPS (Input/Output operations per second), the figures are mind-blowing... 15K SAS drive Enterprise SSD ------------- -------------- 180 Write IOPS 7,000 Write IOPS 320 Read IOPS 35,000 Read IOPS I don't have figures for a SATA drive, but they're lower than SAS. The SSD figures exceed the capabilities of some disk controllers, which can make them difficult to measure. The read IOPS figure is pretty close to being limited by the SAS bus. -- Andrew _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
