Hardware vs. software Raid

[Jeff]

I know the differences between hardware and software raid as written on
various web sites, but I was hoping that someone can tell me about
real-world performance differences for my particular situation in a new
server that I'm currently building. What I seem to be taking out of my
reading is that software raid will take the greatest performance hit for
raid 5 (versus hardware raid 5), where a parity bit has to be calculated -
with raid 0,1, and 10, however, where there is no parity bit to calculate,
there is little performance hit. From what I gather, the performance
degradation should come mostly if the processor is already running near max,
while if it is not, there shouldn't be much if any slowdown in the system.
Also, for the price of a hardware raid controller, I could purchase a second
processor. I hear, however, that hardware raid is less likely to corrupt
data should something go wrong with the server.

Again, I think that the above is correct, but I'm not certain. In my
particular situation, the server will be used primary for a web server and I
need the server to rapidly respond to requests for .aspx pages written in
visual basic, but the overall processor load/bandwidth won't be all that
great.

Also, I am guessing that if I put in a software raid solution (using 4 sas
drives in raid 10), that I likely would have to reinstall the entire OS if I
switched to a hardware PCIe card later?

Jeff

 

[Paul]

I know the differences between hardware and software raid as written on
various web sites, but I was hoping that someone can tell me about
real-world performance differences for my particular situation in a new
server that I'm currently building. What I seem to be taking out of my
reading is that software raid will take the greatest performance hit for
raid 5 (versus hardware raid 5), where a parity bit has to be calculated
- with raid 0,1, and 10, however, where there is no parity bit to
calculate, there is little performance hit. From what I gather, the
performance degradation should come mostly if the processor is already
running near max, while if it is not, there shouldn't be much if any
slowdown in the system. Also, for the price of a hardware raid
controller, I could purchase a second processor. I hear, however, that
hardware raid is less likely to corrupt data should something go wrong
with the server.

Again, I think that the above is correct, but I'm not certain. In my
particular situation, the server will be used primary for a web server
and I need the server to rapidly respond to requests for .aspx pages
written in visual basic, but the overall processor load/bandwidth won't
be all that great.

Also, I am guessing that if I put in a software raid solution (using 4
sas drives in raid 10), that I likely would have to reinstall the entire
OS if I switched to a hardware PCIe card later?

Jeff

There is an article here:

http://www.tomshardware.com/2004/11/19/using_windowsxp_to_make_raid_5_happen/index.html

Paul

 

[yasoof]

I know the differences between hardware and software raid as written on
various web sites, but I was hoping that someone can tell me about
real-world performance differences for my particular situation in a new
server that I'm currently building.

If you go to newegg.com and read the user reviews for the raid
hardware cards, you'll get a better idea of what they do.

The good ones are expensive though. Has to have a hardware
controller, not just be another software/cpu dependent card.

I picked up a sli motherboard just to have the option of a hardware
raid controller in the future. Don't care about dual video cards.