Re: Intel Updates SSDs, Supports TRIM, Faster Writes

[Chris Worley <worleys@gmail.com>]

On Tue, Nov 10, 2009 at 2:42 AM, Kasper Sandberg <postmaster@metanurb.dk> wrote:
> On Mon, 2009-11-09 at 09:59 -0700, Chris Worley wrote:
>> On Mon, Nov 9, 2009 at 9:42 AM, Majed B. <majedb@gmail.com> wrote:
>> > Well, SATA uses SCSI emulation so I guess that's no problem, right?
>>
>> The only problem is SSD's put Solid State Storage (SSS) behind
>> SATA/SAS controllers... while compatible w/ old disk technology, it
>> severely limits performance (i.e. none of these SSD drives do even
>> 300MB/s... while SSS drives do 800MB/s).  While the initial 2.6.27
> No, around 280MB/s... and obviously they dont do more, because of the
> simple limitation of the sata controllers.. this also means they dont
> need to do as many channels as other devices..

I'm not sure if you're agreeing or disagreeing here...
280MB/s<300MB/s, due to the "compatibility" based design of SSD's,
while SSS, w/o a legacy controller, can do 800MB/s out of a single
drive.

>> drivers and ext4 "discard" worked very well with forward-thinking SSS
>> not encumbered by old controller technology... but, SSD's were not
>> able to handle it well:
>>
>> http://lwn.net/Articles/347511/
>>
>> So it looks like "design by committee" Linux is well behind Windows 7,
> And how exactly does windows 7 handle this so much better?

TRIM is in W7; NTFS support.  No Linux distro does.  And by the time
"design by committee" gets through with it,we shouldn't have bothered.

>> while Linux contemplates slowing new technology down to optimize for
>> ill-designed SSD's.
> It does?

Those that speak loudest in the kernel development (and contribute the
most) work for companies like Intel that promote the slower,
controller-based, SSD's.

Chris
>>
>> Be glad "thumb drives" didn't try to be floppy-drive-compatible!!!
>>
>> Chris
>> >
>> > On Mon, Nov 9, 2009 at 7:37 PM, Chris Worley <worleys@gmail.com> wrote:
>> >> On Sun, Nov 8, 2009 at 6:13 PM, Majed B. <majedb@gmail.com> wrote:
>> >>> The firmware which introduced the TRIM command was deemed buggy and
>> >>> has been pulled out.
>> >>>
>> >>> Are there any filesystems that are TRIM-aware?
>> >>
>> >> Ext4 (at that level in the kernel, it's referred to as "discard", it's
>> >> not TRIM until it's issued as a SCSI command).
>> >>
>> >> Chris
>> >>>
>> >>> On Sun, Nov 8, 2009 at 8:57 PM, Bill Davidsen <davidsen@tmr.com> wrote:
>> >>>> For those of us playing with use of SSD for journals on ext[34], this does
>> >>>> have implications for RAID performance.
>> >>>>
>> >>>> http://hardware.slashdot.org/story/09/10/27/1427209/Intel-Updates-SSDs-Supports-TRIM-Faster-Writes
>> >>>>
>> >>>> --
>> >>>> Bill Davidsen <davidsen@tmr.com>
>> >>>>  Unintended results are the well-earned reward for incompetence.
>> >>>>
>> >>>>
>> >>>> --
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>> >>>>
>> >>>
>> >>>
>> >>>
>> >>> --
>> >>>       Majed B.
>> >>> --
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>> >>>
>> >>
>> >
>> >
>> >
>> > --
>> >       Majed B.
>> >
>> --
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>
>
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