Re: Linux 2.6.29

From: Jeff Garzik
Date: Fri Apr 03 2009 - 17:48:58 EST


Linus Torvalds wrote:

On Fri, 3 Apr 2009, Jeff Garzik wrote:
Yeah, it's a no-name SSD.

I've attached 'hdparm -I' in case anyone is curious. It's from newegg.com, so
nothing NDA'd or sekrit.

Hmm. Does it do ok on the "random write" test? There's a few non-intel controllers that are fine - apparently the newer samsung ones, and the one from Indilinx.

But I _think_ G.SKILL uses those horribly broken JMicron controllers. Judging by your performance numbers, it's the slightly fancier double controller version (ie basically an internal RAID0 of two identical JMicron controllers, each handling half of the flash chips).

Quoting from the review at
http://www.bit-tech.net/hardware/storage/2008/12/03/g-skill-patriot-and-intel-ssd-test/2

"Cracking the drive open reveals the PCB fitted with sixteen Samsung 840, 8GB MLC NAND flash memory modules, linked to a J-Micron JMF 602 storage controller chip."


Try a random write test. If it's the JMicron controllers, performance will plummet to a few tens of kilobytes per second.

Since I am hacking on osdblk currently, I was too slack to code up a test. This is what bonnie++ says, at least...

Version 1.03c ------Sequential Output------ --Sequential Input- --Random-
-Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
bd.yyz.us 8000M 28678 6 27836 5 133246 12 5237 10
------Sequential Create------ --------Random Create--------
-Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
16 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++
bd.yyz.us,8000M,,,28678,6,27836,5,,,133246,12,5236.6,10,16,+++++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++

But I guess seeks are not very helpful on an SSD :) Any pre-built random write tests out there?

Regards,

Jeff



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