P35 Boards + ICH9R Raid Contollers

[jto168]

I will be configuring six hard drives (2*250, 2*320, 2*500) and one optical drive for a system using the Gigabyte GA-P35-DS3R motherboard and I have a few questions.

Please note that the ICH9R controller has six SATA ports, while the Gigabyte IC controller has two SATA ports. Total number of ports is eight (8).

What is the effect of running the following configuration of RAID arrays in terms of performance:

RAID 0 (system) - ICH9R x 2 ports
RAID 1 (critical storage) - ICH9R x 2 ports

Non-Raid (optical drive) - ICH9R x 1 port
Non-Raid (non-critical storage) - GA IC x 2 ports

By having two RAID channels running off the ICH9R controller, would there be any decrease in read/write speeds?

Would having a Non-Raid item on the ICH9R controller affect the performance of the two RAID channels?

A friend also recommended the following configuration which he believes would be better as each array would have its own dedicated controller for its intended purpose:

RAID 0 (system) - GA IC x 2 ports
RAID 1 (critical storage) - ICH9R x 2 ports

Non-Raid (optical drive) - ICH9R x 1 port
Non-Raid (non-critical storage) - ICH9R x 2 ports

Comments?

 

[postmortemIA]

Friend obviously doesn't know that gigabyte (or jmicron, whatever it is) controller is bound to PCI bus speeds, which means max 133MB/s... unless those controllers have PCI-e interface, which I somephow doubt.

My suggestion? Use Matrix RAID, that is 4 drives in both RAID0 and RAID1 array at same time, that is what ICH9R provides, that you can have both RAID0 and RAID1 on same set of drives.

http://www.intel.com/design/ch...s/matrixstorage_sb.htm

 

[jto168]

Thank you for the excellent reply.

I did not realize that the Jmicron controller was bound to PCI bus speeds, and it seems my friend did not either!

I'm just trying to figure out if I should put all the RAID channels together on the ICH9R controller and if it would in any way affect the read/write performance of eachother. Correct me if I'm wrong, but would more channels on a given controller tend to stress out the controller and thus have a negative impact on the performance?

At the same time, it can be argued that it would be a trade off to run the RAID 0 system array using the Gigabyte IC controller as it would be slower than the ICH9R. But how much worse would this perform than if both RAID channels were running from the ICH9R controller, if at all?

I know the gains from RAID 0 are marginal at best, but I have become accustomed to using software based RAID controllers (nForce 4 currently) and I don't think anyone will disagree with me when I say that I want to get the most out of my motherboard.

 

[jto168]

Originally posted by: postmortemIA
My suggestion? Use Matrix RAID, that is 4 drives in both RAID0 and RAID1 array at same time, that is what ICH9R provides, that you can have both RAID0 and RAID1 on same set of drives.

http://www.intel.com/design/ch...s/matrixstorage_sb.htm

When you say 4 drives in Both RAID 0 and RAID1 array at the same time, do you mean two separate arrays such as 2*250 RAID 0, and 2*320 RAID 1?

I am slightly confused about your last statement, "that you can have both RAID0 and RAID1 on same set of drives".

 

[jto168]

Hello again...

After doing some research and reading about Matrix Raid in depth, I was able to understand your statement.

Thank you.

 

[renethx]

Originally posted by: postmortemIA
Friend obviously doesn't know that gigabyte (or jmicron, whatever it is) controller is bound to PCI bus speeds, which means max 133MB/s... unless those controllers have PCI-e interface, which I somephow doubt.

GIGABYTE SATA2 (= JMB363) is a PCI Express x1 to two-port SATA II and one-port PATA host controller (250MB/s per direction). Please look at the block diagram at page 8 of the manual or JMB363 product page.

 

[postmortemIA]

Originally posted by: renethx

Originally posted by: postmortemIA
Friend obviously doesn't know that gigabyte (or jmicron, whatever it is) controller is bound to PCI bus speeds, which means max 133MB/s... unless those controllers have PCI-e interface, which I somephow doubt.

GIGABYTE SATA2 (= JMB363) is a PCI Express x1 to two-port SATA II and one-port PATA host controller (250MB/s per direction). Please look at the block diagram at page 8 of the manual or JMB363 product page.

sorry, I was wrong , but at least I suspected it might be the case

 

[Madwand1]

Separate drives / arrays will sometimes give better performance than Matrix array splits, because the when you flip between one Matrix array and another, you incur additional seeks on the referenced drives. This is very easy to see for example on a transfer test between separate arrays vs. matrix ones using the same drives.

I haven't seen any indication that the Intel controller slows down when multiple arrays are being used, but I wouldn't rule it out without testing. I suggest testing this for yourself as follows: Set up a simple drive with the OS, and some test utilities. Set up the arrays in various configurations, and test concurrent performance using benchmark utilities.

I personally do something like this anyways -- keep the OS on a simple separate drive, which makes setup and maintenance easier.

BTW, if you have something really critical, then a better setup would be to use simple drives and external backup. External disconnect backups can cover a number of failure modes that RAID cannot -- all that RAID can do is handle a single drive failure, not user error / software error / malware / massive PSU failure, etc.. So consider splitting up that RAID 1 array into a simple drive and an extern eSATA/Firewire/USB drive. Disconnect and turn off the external when not in use. And of course do regular backup.