"Mikael Antonsen" wrote in message
. ..
Jez T skrev:
"Mikael Antonsen" wrote
But still, 5x Write speed with that module.
I just dont think ppl that bought the 642 without would think.."ohh
thats a okai speed".
I know the acceleration will help in some ways yes, but still.
There really must be something wrong here.

Actually, most ppl who buy a 642 never bother testing disk performance,
so would never notice either way.

For an objective performance, try IOMETER
http://www.iometer.org/
That's the 'standard' for testing disk performance.


what cluster size do you normally test with in IOMETER ?

And yes it seems like you guys really mean that 10MB/s is okai for a
raidcontroller without Battery stuff.
I really dont think they would make a raidcontroller that would perform so
slow?

there are many, many factors that determine array controller performance.
None of us are saying that 10MB/s is "okai", just that it is not suprising
given your setup, and lack of other important details in your post.

Determining your cluster size can be a tricky thing. What it comes down to
is what type of application(s) you are running on your server, and what is
optimal for those apps. If its MSSQL ... 64K. If its Exchange, 4K. If its a
file/print server, it then depneds on your typical data sets ... hundreds of
large files, hundreds of thousands of small files ???? There is no
one-size-fits-all that will get the best performance in all cases. Beware
that you can adversely affect performance, AND waste disk space if you do
not use the optimal cluster size. Trial and error is usually a fair approach
to figuring this out. Also, with windows (i dont do opensource), the
cluster size is determined at the time you format your partions. The only
volume you do not get this choice with is your boot partition, as that is
created for you during setup.

Also take into consideration the Stripe Size (how much data is
read-from/written-to the disk at a time. a 16K stripe will out perform a 4K
stripe in most cases. I usually use the highest value available (128K or
256K), depending on the controller.

How did you do your testing to determine what your performance was ?

- LC