Integrated ICH9R Raid Array w/3-Drives

[Pacal]

Greetings,

I have a 3-Drives presently and they run off the integrated ICH9Raid Controller as of present. I am attempting to pin-down the best performance configuration for my system and my experience with complex raid arrays and the associated benefits are brief.

The Intel Matrix Storage Manager (IMSM) will only permit me stripe (Raid-0) the 3-Drives which renders them non-bootable which is hardly beneficial as my primary storage array. I can also configure them in a Raid-5 array and not only is it bootable, but Vista64 seems content with it.

My big question is... Should I invest in a 4th drive and attempt a Raid 1+0/10 configuration or be content with my 3-Drives and Raid-5 array?

~Pacal

 

[MerlinRML]

First of all, I'm not super familiar with all of the ins and outs of Matrix RAID, but I'm surprised you can't boot from your RAID 0. Maybe it's their attempt to keep people from running potential dangerous configurations.

It's hard to say what will provide you with the best performance, since each person's computer usage is different. If you're doing your typical surfing and officey type stuff, you won't see much benefit from any RAID configuration, as a single disk is usually good enough.

Anyway, on to your questions about RAID 5 vs RAID 10 vs RAID 0 + 1. Another option you didn't consider is a 4 disk RAID 5.

A 3 drive RAID 5 is going to have the highest CPU load as it calculates parity bits for every piece of data you write. It's also going to have the slowest writes, since it has to calculate parity. Reads should be fairly strong. You'll have 2 disks worth of space to play with, only sacrificing a single disk's worth of space. Performance should be a bit below 2 disks worth of performance. Any time you lose a single disk, rebuilds will be slow as you rebuild from the parity stripe, and overall performance will suffer.

A RAID 10 (2 RAID 1's with a 0 stripe on top of them) is going to cost you 2 disk's worth of space. CPU load should be lower than RAID 5 since you don't have to calculate parity. Reads and writes should be equivalent to the performance of 2 disks. You can handle up to 2 disks failing at the same time (as long as it's the correct 2 disks, 1 in each lower level RAID 1), and rebuilds should be relatively quick as you just have to mirror a single drive's data for each failure.

A RAID 0 + 1 (2 RAID 0's with a RAID 1 stripe on top of them) is very similar in concept to a RAID 10. CPU, performance, and space are going to be pretty much identical. However, you can only handle 1 disk failure, and a rebuild is going to take a very long time as you have to rebuild 2 drives worth of data.

A RAID 10 is probably the best of the bunch (in terms of performance and cpu load) if you're willing to sacrifice the extra space.

 

[Pacal]

Thank you MerlinRML,

That information was invaluable. Ideally I'd like to get all my drives out of the chassis and locked tight in an external array with only the memory or some solid-state storage for local access/caching.

~Pacal