IDE RAID vs. WinNT/2k Software Striping

[ryandlugosz]

Here's a question that came up the other day on a small technical listserv....

If someone is looking for RAID 0 (or even RAID 1), and they've got ATA100 controllers already on their mobo, should they buy a seperate IDE RAID card?

I know cards like the FastTrak are actually software based so is it really that much of a difference to justify the $70? Seems like their software is probably only a little more optimized than "Windows Raid". I do see the benefit in that the FastTrak has a buffer on it that most mobo IDE controllers lack. It does have a buffer, right?

Anyway, I haven't found the answer to this question in any of the IDE RAID reviews that I've read, including Anand's. It's an important question that could save some people some money.

I'd like to see how it (windows raid) stacks up against a true hardware IDE card (not the FastTrak) as well.... It seems like the bottleneck isn't going to be in the slight additional processing that the CPU has to do.

Maybe this would be a good addendum review for Anand to throw on the end of his IDE RAID review!

-Ryan

 

[Athlon4all]

Well, asuming the ATA/100 is a RAID controller then no. The PCI card will still use the same CPU cycles as the on-board will. And, I'm just going to say, if u are in for RAID, FORGET NT/2000 RAID. It performs very very poorly, stay away from it, maybe that's why it disappeared in Windows 2000 Pro. Well, see here's the problem when comparing Hardware Vs. Software, Hardware is meant for RAID 5, which by nature isn't as high performing as RAID 0 and even when in RAID 0, Hardware was beat by the software cards because a fast CPU (A high PIII, Athlon, or P4) will be faster than the on-board CPU on the Hardware RAID cards. And as far as CPU untilization goes, people don't realize this, but the Calcs for RAID 0 increase CPU utiliaztation over a normal ATA/100 drive at most by only 1%, so the difference is very small when using RAID 0. So In my opinion, the bottom line is:

1. Stay away from NT/2000 "Software" RAID
2. Forget Hardware RAID, unless running RAID 5.

 

[Pariah]

"It performs very very poorly, stay away from it"

In a 2 drive environment, NT/2k software RAID will perform just as well as hardware. As you add drives, the performance delta increases.

"maybe that's why it disappeared in Windows 2000 Pro."

Win2k pro still has RAID 0 and 1, don't know who told you otherwise.

"Hardware was beat by the software cards because a fast CPU (A high PIII, Athlon, or P4) will be faster than the on-board CPU on the Hardware RAID cards."

Huh? RAID 0 requires almost no calculations, the limiting factor is almost always the drives or drivers, not the controller/CPU.

If you run win2k exclusively, then software RAID will save you a bit. Just keep in mind the limitations of an OS based RAID implementation. Performance in a 2 drive array will be comparable to hardware.