Windows RAID vs Intel RST vs RAID-Z vs hardware RAID?

[Asphodelus]

What are the pros and cons of each of these RAID methods?

 

[mikeymikec]

I'll skip past RAID-Z as I don't know anything about it.

Windows RAID sucks according to a lot of people. I haven't used it a great deal but when I have used it I haven't had any problems with it. I imagine MS will drop it completely sooner rather than later if they haven't already because of the availability of other RAID solutions.

Intel RAID, which I'll label 'desktop RAID', is a bit "RAID-lite". Desktop RAID can sometimes have problems like losing the RAID configuration because it's stored in the CMOS and backed up by a wimpy battery and nothing else. I don't know whether Intel RST also suffers from this drawback but I imagine it does. I also imagine that desktop RAID would perform a little better than Windows RAID since it would have a better rapport with the hardware involved.

Hardware RAID, (assuming that this means a chunky and fairly expensive RAID card) means better backed-up RAID configurations and probably better performance due to dedicated RAID memory cache.

I'm not a RAID expert, that's my $0.02

 

[Virge_]

Ultimately it's a matter of cost (hardware vs. integrated/windows). I've worked with various levels of consumer to enterprise RAID for many years, but I still consider myself intermediate so someone more knowledgeable is welcome to chime in and correct anything incorrect, but here is a thousand foot level:

Windows Raid : I would not even consider this real RAID. You take a small performance hit (roughly 75%-80% of the speed) vs. using IRST, and it's labeled as "Spanned", "Striped", and "Mirrored" by the OS instead of the usual Raid0/1/5/6/etc. Has limitations on sizes and harsh requirements for MBR/GPT configurations to optimize.

Intel or Marvell RAID : IRST is actually pretty sound. Configurable via BIOS or with the IRST software, allows for the typical important things like e-mail alerts (you'll have to run your own mail server relay, usually), and has average performance if you pair your system with a UPS and enable write-back cache (vs. write-through without). I personally avoid Marvell integrated RAID like the plague due to extremely poor performance (worse by far than Windows "RAID"), but some of their actual hardware solutions are alright.

Hardware RAID : Dedicated hardware controller doing the processing (vs. your CPU handling the RAID in Windows/Integrated mentioned prior) which leads to the fastest performance without noticeable system impact. Either an integrated card for servers or commonly a PCI-E (1x/4x/8x) card for desktops and HTPC's. Has the highest flexibility for number of drives. Options include built-in cache for insane speed boosts to throughput and battery backups connected to the controller in the event of power-failure. Downside is, obviously, cost - with low-end cards starting around $300 and high end anywhere from $800-$2000.

Generally speaking using the integrated RAID chip on a motherboard makes the most practical sense for things like HTPC's and home-use, purely because the controller can cost as much as all the rest of your equipment combined in these situations. I don't do storage as my day-to-day, so this is just my two cents as well.

 

[aigomorla]

hardware raid.... it totally depends on the IOP controller + cache + what kind of Raid Array your setting up.