X-bit labs

Promise FastTrak TX4200 4-Port Serial ATA RAID Controller Review (page 6)

Category: Storage

by Alexey Volkov , Nikita Nikolaichev

[ 06/03/2005 | 02:43 PM ]

Performance in Intel IOMeter Sequential Read and Write Patterns

IOMeter is sending a stream of read/write requests to the array with request queue depth = 4. Every minute the size of the data block changes, so we can see the dependence of the linear read/write speed on the data block size as the result.

Click here to view the complete table of results obtained in IOMeter: Sequential Read.

We build a table of efficiency, like in the previous pattern:

First we construct graphs for the RAID0s and then for the rest of the arrays.

TCQ brings no evident gains to the RAID0 arrays, while the more complex RAID10 array slows down considerably in the TCQ mode. The controller’s drivers evidently need additional improvement…

And what about writing?

Click here to view the complete table of results obtained in IOMeter: Sequential Write.

And the graphs:

There are clearly problems with writing to the arrays consisting of many disks. The scalability of the three-disk array worsens (the write speed of the three-disk array is not 1.5 times higher than that of the two-disk array), and then the controller fails utterly with the four-disk array. The write speed of this array is low irrespective of the operational mode of the drives.

The write speed of the complex RAID1 and RAID10 arrays is fluctuating around the speed of the single drive. Well, it’s always good to have some stability. :)

Next, we’re going to examine the controller’s performance in patterns that emulate the disk subsystem of a server.