ICH8R Question

[TunaBoo]

Hi,

Looking at the Asus P5B deluxe to put with a Q6600. Picked this board because it has the ICH8R which has a little nicer raid support built in. I can't figure out the limitations of the controller though.

I KNOW its limited to 4 devices in an array.. but not sure what other limitations.

Ideally I want to run 4x drives in a raid 5 (speed not important, just want much space with some degree of reliability).

Also want 2 drives in raid 0 for speed (raptors)

I know either one alone is fine.. but no idea if I can do both at once. I am having a hard time telling...

Anyone try this themselves? What are the limitations of the ICH8R. If not I will have to put the raid5 crap in another computer with an add in controller card...

 

[BonzaiDuck]

From more than one direction, I had heard two months ago that there were problems with the ICH8R for on-board software RAID. There were stories about "drives dropping out" -- that sort of thing.

I have friends fairly new to any full understanding of this technology, and who want to have the "best" and then newest. They may have pointed out that they had "ICH8R" with their motherboard choices, as if to show that they were near the "bleeding edge."

The fact is, the difference between ICH7R and ICH8R is that the latter allows for a larger number of disks cabled to the motherboard. For performance, the differences seem limited to the one I've cited, because there is no difference in speed, throughput, bandwidth -- whatever defines raw performance.

That being said, it is quite possible the ICH8R shortcomings could be resolved through BIOS revision.

Have you looked into the performance limits of a 3-disk, "software" RAID5? For the size of the array, you'd only need to purchase larger hard disks -- look into the "perpendicular" technology -- and this would reduce your power requirement. If you want more performance and equal reliability, get a hardware RAID controller with an onboard parity-calculation engine or RISC processor. But with that, you'd either need a motherboard with PCI-X slots, or a board with spare PCI-E slots that can be used for x4 or x8 PCI-E RAID controllers, and which don't reduce the number of PCI-E lanes for the kind of graphics you want to have. I don't think the P5B is quite up to the task in that event.

 

[TunaBoo]

The thing is.. the raid5 is just to store stuff like DVDs.. speed is not important, as even the slowest software controller will let me read a DVD off in real time. Am looking for a cheap way to get redundant storage, and raid5 is it. 4 500 gig disks can be had for under $500.. giving me 1.5 TB of redundant storage.. great for my needs.

Yah other choice is buy a ICH7 or nvidia board, and then a junky software SATA raid controller. Hum

 

[Madwand1]

Yes, you can have two separate arrays spanning 6 drives in ICH8x, but no array spanning > 4 drives. At least for now, with the ICH8x implementations I've heard of.

You can also have two arrays on the same set of drives.