do raid1 controllers multitask read operations

Island · 01-21-2010, 03:48 AM

Will either the 3ware 9650 2 Port Hardware RAID - $20 per month or the 3ware 9550SX Hardware RAID - $45 per month multitask read operations? What I mean is if the web server is requesting two files at a given moment and if you setup a raid1 array on one of these controllers, will the controller read one file from one disk and one file from the other disk simultaneously? Do you get an appreciable boost in read IOPS by using a simple raid controller like this?

Island · 01-21-2010, 04:13 PM

Well, I got a pair of Western Digital RE3 1 TB drives on a local machine and gave it a quick test in RAID1 vs. a single disk using HDTach:

Now this is on windows, and I'd be looking at linux for a server here, but it's interesting how the cpu usage as reported by the hdtach test is noticably less.

HDTune's test doesn't show the same cpu benefit, but likewise shows a really noticeable improvement in read performance going with raid1 vs. a standalone disk.
and then using HDTune

Now of course the million dollar question is how this translates to a web server. For example, you could go with two less expensive sata drives or one 10k velociraptor for the /home directory... The 10k velociraptor delivers lower access time and better write performance, but the pair in raid-1 deliver better *sustained* read performance (plus redundancy). Of course, how the sustained throughput compares with the serving of typical web files is a question.

(I really like the tempting disk options here - makes a bit of a hard decision on a budget, but it's great to have many good options to consider on the table.)

Island · 02-24-2010, 04:45 PM

I found http://www.xbitlabs.com/articles/sto...e_8.html#sect0 directly on topic addressing IOPs of single disk vs. raid1, raid10, etc on a 3ware 9650 controller.

LesterW · 03-24-2010, 06:52 PM

Interesting results.... thanks for sharing with us!

I've been wondering how a RAID setup like this would translate to a web server environment a well. I've been playing with Adaptec RAID cards though.. so yeah.

01-21-2010, 03:48 AM	#1
Island Member Join Date: Mar 2008 Posts: 44	do raid1 controllers multitask read operations Will either the 3ware 9650 2 Port Hardware RAID - $20 per month or the 3ware 9550SX Hardware RAID - $45 per month multitask read operations? What I mean is if the web server is requesting two files at a given moment and if you setup a raid1 array on one of these controllers, will the controller read one file from one disk and one file from the other disk simultaneously? Do you get an appreciable boost in read IOPS by using a simple raid controller like this? __________________ Boat Design & Boatbuilding Forums

01-21-2010, 04:13 PM	#2
Island Member Join Date: Mar 2008 Posts: 44	Well, I got a pair of Western Digital RE3 1 TB drives on a local machine and gave it a quick test in RAID1 vs. a single disk using HDTach: Now this is on windows, and I'd be looking at linux for a server here, but it's interesting how the cpu usage as reported by the hdtach test is noticably less. HDTune's test doesn't show the same cpu benefit, but likewise shows a really noticeable improvement in read performance going with raid1 vs. a standalone disk. and then using HDTune Now of course the million dollar question is how this translates to a web server. For example, you could go with two less expensive sata drives or one 10k velociraptor for the /home directory... The 10k velociraptor delivers lower access time and better write performance, but the pair in raid-1 deliver better sustained read performance (plus redundancy). Of course, how the sustained throughput compares with the serving of typical web files is a question. (I really like the tempting disk options here - makes a bit of a hard decision on a budget, but it's great to have many good options to consider on the table.) __________________ Boat Design & Boatbuilding Forums

02-24-2010, 04:45 PM	#3
Island Member Join Date: Mar 2008 Posts: 44	I found http://www.xbitlabs.com/articles/sto...e_8.html#sect0 directly on topic addressing IOPs of single disk vs. raid1, raid10, etc on a 3ware 9650 controller. __________________ Boat Design & Boatbuilding Forums

03-24-2010, 06:52 PM	#4
LesterW Junior Member Join Date: Mar 2010 Posts: 7	Interesting results.... thanks for sharing with us! I've been wondering how a RAID setup like this would translate to a web server environment a well. I've been playing with Adaptec RAID cards though.. so yeah.