How many I/Os per disk

[Patrick Terlisten]

Hello,

can someone tell me how many I/Os each of this disks can perform?

U320 SCSI, 10k upm
U320 SCSI, 15k upm
SATA 5,4k upm
SATA 7,2k upm

I think that the FATA an FC drives that could pe used in an EVA will handle the same amount of I/Os.

I heared, some years ago, that a 10k upm U320 disk will achieve round about 150 I/Os. A 15k disk achieve 190 I/Os. I don´t have any values for SATA disks.

Thanks for your help.

Regards,
Patrick

[Jefferson Humber]

Patrick,

Tricky question, similar to one I asked a little while ago.

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=1014228

Jeff

[Patrick Terlisten]

Hello Jefferson,

according to your thread I think that my 150 I/Os may be a realistic value.

10000 upm / 60 seconds = ca. 167 I/Os
15000 upm / 60 seconds = ca. 250 I/Os

If a disk do one I/O per rotation, this formula will give me values for a "perfect world enviroment". But IMHO can do a disk more than one I/O per second, depending on the number of write / read heads and disks in the harddrive, right?

Regards,
Patrick

[John Kufrovich]

>But IMHO can do a disk more than one I/O >per second, depending on the number of >write / read heads and disks in the >harddrive, right?

Patrick,
Look at the your results and reread your statement above. Yes, a drive can do more than 1 I/O ps.

The mechanics of any hard drive limits the number of I/Ops. Sequential access will give you high IOps than random. Realistically 15k, sequential performance will be around 150IOps. This number is taking into account for seeks.

jk

[Cass Witkowski]

This URL may have the answers you are looking for.

http://www.hp.com/products/harddiskdrives


Also remember that SATA drives have a much lower duty cycle rating. This means that if your are expecting to use the drives with a duty cycle of 20%- 30% then you should look at the SCSI drives.

[Lethuillier]

Take a look at this comparison sheet :

http://www.westerndigital.com/en/library/sata/2579-001097.pdf

[Patrick Terlisten]

Thanks for your replies. The link to Western Digital is nice, but a little bit "WD minded". ;)

Regards,
Patrick