Chris,

Do you mind sharing the drive models & controllers you're using that
give you 800 MB/s?

On Tue, Nov 10, 2009 at 7:18 PM, Chris Worley [off-list ref] wrote:

On Tue, Nov 10, 2009 at 9:01 AM, Majed B. [off-list ref] wrote:

quoted

Which disks can provide 2ms response with a read of 250 MB/s and write
of 170 MB/s other than SSDs?!

The drives I use average <50usecs latency at 4KB packets (properly
measured as the complete turn-around time of a single outstanding
I/O), 800MB/s reads and >600MB/s writes at 128KB blocks.

quoted

Are you saying that it doesn't matter whether we use Linux or Windows
with SSDs because the limitation is coming from the disk's controller
itself?

To some degree, yes, when using SSD's behind a controller, the
controller is the biggest performance issue, and given they use
chicklets for processors, they all hamper performance given the speed
potential of the underlying storage.

As none of the enterprise distros are handling TRIM yet, W7 can claim
it was first, and putting together a TRIM-capable kernel is manual
currently in Linux, and given only ext4 supports it (strangely, FAT
supported it, then the code was pulled... XFS may support it, but I
believe that's still in the works), you have the additional problem
that ext4 has some maturity issues.  Porting "discard" to ext2/3 would
not be too difficult, especially w/o journal considerations.

Chris

quoted

On Tue, Nov 10, 2009 at 6:58 PM, Chris Worley [off-list ref] wrote:

quoted

On Tue, Nov 10, 2009 at 8:43 AM, Majed B. [off-list ref] wrote:

quoted

Does that mean we won't be able to squeeze the juice out of Intel's
Extreme SSDs on Linux?

The limitation is in the design.  You'll be able to get as much
performance as they can offer, given the bad design (of putting SSS
behind legacy controllers).

-- 
       Majed B.
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