Any difference between Hardware RAID and Software RAID?

I'm building a new server (Small Business Server 2008), but I can't get the built-in RAID controller (AMD SB700) to work and have basically given up on it ever working with Server 2008. Fine.

But my question is... is there any real difference between Hardware (such as this one) and Software (Window's built in Drive Mirroring) for RAID 1?

Assuming the drives are identical models, etc., it seems that there would be a negligible difference, just based on my guessing/wishfull thinking.

Alex Papadimoulis

Posted 2009-08-23T15:43:05.820

Reputation: 233

Answers

Software Vs Hardware RAID in general; also at Serverfault.
Short RAID 1 discussion (CentOS context).
Serverfault: Build a software raid 1 on windows XP might also be useful for software RAID 1.
Serverfault: How do I differentiate “fake RAID” from real RAID?

nik

Posted 2009-08-23T15:43:05.820

Reputation: 50 788

Ah ha, didn't think to try Server Fault – Alex Papadimoulis – 2009-08-23T17:09:15.087

4yes, who could possibly imagine asking a server-related question on a site named "Server Fault"?! :) – Jeff Atwood – 2009-08-23T20:19:28.523

A few obvious differences:

With software RAID you are limited to the SATA ports on your motherboard. Some RAID cards allow, say, 10 SATA drives to be connected.
Software RAID uses additional CPU time, whereas a hardware RAID offloads such processing onto the RAID card. It depends on how you use the RAID, but this probably wont add significant load (CPU's are rather fast now..)
Software RAID is infinitely cheaper, since it's (probably) included with your OS already
A software RAID is more portable, tied to a specific operating system, rather than a specific RAID card brand or model ("RAID interoperability")
(Personal opinion) Slightly unfounded, but I trust software RAID more than then drivers for RAID cards - software engineers are generally better at making software than hardware engineers!

One isn't better than the other - both have their advantages..

If you're concerned about performance, or need more drives than your motherboard will take, you should go with a RAID card (although it's worth trying/benchmarking software RAID before you buy a RAID card)

dbr

Posted 2009-08-23T15:43:05.820

Reputation: 4 987

Hardware usually has better support for hotswap with separate hardware logic/circuitry, easier identification of failed drives by blinking lights, bootable volumes for any raid level and so on... performance-wise? Not really, as long as there're cpu-cycles left and the software implementation is good enough...

...but as nik has pointed out - hardware isn't always "hardware" and generally "it depends".

Oskar Duveborn

Posted 2009-08-23T15:43:05.820

Reputation: 2 616