Re: Linux 2.6.29

Jeff Garzik
2009-04-03T21:48:57Z

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