3 ms·
You're under 500 IOPS per HDD, period This is only significant if one is limited to a trivial number of spinning disks. 20 years ago, with separate disk contro
by mmt 16y ago
You're under 500 IOPS per HDD, period
This is only significant if one is limited to a trivial number of spinning disks. 20 years ago, with separate disk controllers, this was the case.
If you run some benchmarks, I expect you'll find that, for random I/O, N disks perform better than N times one of those disks.
SCSI provided (arguably) an order of magnitude for number of disks per system.
Now, SAS provides another. $8k will buy 100 disks (and enclosures, expanders, etc). How many IOPS is that?
ETA: The Fujitsu Eagle (my archetype of 20ish years ago disk technology) had, IIRC, an average access time of 28ms. If its sequential transfer rate was one 60-100th of modern disks, what fraction of a modern disk's 4k IOPS could it do?
- jbooth 16y agoYes, I agree that the solution is to throw more spindles at the problem. PL/SQL, though, with global data reach and advanced locking states for every single transaction, make it really hard to move off of a single host. So it's more and more work to get more disks attached to that host, and CPU is a hard upper limit.