3 ms·
Basically on a PCIe 3.0 x4 maximum performance is 4000GB/s, in practice this is 3200-3500MB/s. With 4k random write, you will get maximum 800.000 to 875.000 iop
by olavgg 10y ago
Basically on a PCIe 3.0 x4 maximum performance is 4000GB/s, in practice this is 3200-3500MB/s. With 4k random write, you will get maximum 800.000 to 875.000 iops per second. Consumer-grade SSD's barely manage to write 500-1000 iops when sending the ATA_CMD_FLUSH command unless they are lying which is really bad.
Good read about consumer SSD performance:
http://www.sebastien-han.fr/blog/2014/10/10/ceph-how-to-test-if-your-ssd-is-suitable-as-a-journal-device/ http://www.sebastien-han.fr/blog/2014/10/10/ceph-how-to-test...
- erik 10y agoRight, elsewhere in these comments it was pointed out that they are talking about a 1,000x improvement in latency vs flash memory. If they are using PCIe x4 and x2, then it seems that their throughput isn't going to be much better than existing SSDs. Improved 4k random read and write would of course sill be a big win.
- daveguy 10y agonitpick: iops is I/O operations per second. iops per second is redundant -- would be like FLOPS per second.
- johnm1019 10y agoand I still use ATM machines....
- Buge 10y agoYou made a 3 order of magnitude jump. Is that a typo?