RAID 0+1 vs RAID 5

Lifeismusic · 01-10-2007, 11:05 PM

Hey all, I have another RAID question. I was talking to someone on another forum, and they said that RAID 5 might be better than RAID 0+1. Now, from what I've read, RAID 5 seems to be slightly slower than RAID 0+1, because when reading it has to skip the parity blocks. However, I would have more useable space with RAID 5, and I could also add HDDs, without have to reformat.

My question is, is there a noticable performance decrease with RAID 5 as opposed to RAID 0+1? I was also told that if I do RAID 5 I should get a controller card, rather than use the onboard controller. Unfortunatly, I can't spend $100-300 on a RAID card, so I would have to use the onboard. Would that create a problem of any sort? Basically, which is better, RAID 0+1 or 5?

Thanks!

crazijoe · 01-11-2007, 06:56 AM

For the OS and apps I usually recommend RAID 0, 1, or 0+1. For data storage I usually recommend RAID 5.
RAID 5 is actually slower in performance than RAID 1 . It is known to be slower for writes, because of the CPU overhead that is reqiured for each write. You can put the OS on a RAID 5 but you might find the system performance to suffer.
The plus to a RAID 5 is it's ability to rebuild on the fly. Another note, optimal configuration for a RAID 5 is 4 to 6 identical disks plus a hot spare. Less than that is not worth it and a RAID 1 would be a better choice.

Lifeismusic · 01-11-2007, 11:33 AM

Thanks for the reply. I would rather have performance than the ability to rebuild on the fly or add new disks.

I have 4x 250GB WDs, but not a spare. It's looking like RAID 0+1 is my best bet. Thank you for your input, it's always nice to have a more knowledgable person confirm what you thought you should do.

01-10-2007, 11:05 PM	#1 (permalink)
Lifeismusic Registered User Join Date: Jul 2005 Posts: 159 OS: XP Home My System	RAID 0+1 vs RAID 5 Hey all, I have another RAID question. I was talking to someone on another forum, and they said that RAID 5 might be better than RAID 0+1. Now, from what I've read, RAID 5 seems to be slightly slower than RAID 0+1, because when reading it has to skip the parity blocks. However, I would have more useable space with RAID 5, and I could also add HDDs, without have to reformat. My question is, is there a noticable performance decrease with RAID 5 as opposed to RAID 0+1? I was also told that if I do RAID 5 I should get a controller card, rather than use the onboard controller. Unfortunatly, I can't spend $100-300 on a RAID card, so I would have to use the onboard. Would that create a problem of any sort? Basically, which is better, RAID 0+1 or 5? Thanks!

01-11-2007, 06:56 AM	#2 (permalink)
crazijoe Registered User Join Date: Oct 2004 Location: Omaha, The Center of the Universe Posts: 7,632 OS: WinXP, Win2K3 My System	For the OS and apps I usually recommend RAID 0, 1, or 0+1. For data storage I usually recommend RAID 5. RAID 5 is actually slower in performance than RAID 1 . It is known to be slower for writes, because of the CPU overhead that is reqiured for each write. You can put the OS on a RAID 5 but you might find the system performance to suffer. The plus to a RAID 5 is it's ability to rebuild on the fly. Another note, optimal configuration for a RAID 5 is 4 to 6 identical disks plus a hot spare. Less than that is not worth it and a RAID 1 would be a better choice. __________________ Microsoft MCSA + Messaging, MVP, A+, Network+ http://i16.photobucket.com/albums/b3...other/Help.jpg Do you want a real Republican? HDD diagnostic tools / HDD data recovery software

01-11-2007, 11:33 AM	#3 (permalink)
Lifeismusic Registered User Join Date: Jul 2005 Posts: 159 OS: XP Home My System	Thanks for the reply. I would rather have performance than the ability to rebuild on the fly or add new disks. I have 4x 250GB WDs, but not a spare. It's looking like RAID 0+1 is my best bet. Thank you for your input, it's always nice to have a more knowledgable person confirm what you thought you should do.