RocketRaid 2220 vs. Win 2k Software Raid 5

[Micah]

I upgraded my media server because of lack luster performance in its original configuration and here's the results.

Original Configuration:

Dell PowerEdge 600SC
1.8GHz Intel Celeron
128k RAM
5 120G IDE Hard Drives running Windows 2k Server Software RAID 5


Performance:

When ripping DVDs directly to the server from the htpc across my network the CPU usage was 99% the entire time. Network speeds averaged under 1MB and the rip would frequently fail. When a rip was successful it would usually take nearly an hour and a half to complete.

When loading the music or video libraries through meedio it could take up to a minute to pull all the album covers and info.

In a word, it was SLOW.


New Configuration:

Dell PowerEdge 600SC
1.8GHz Intel Celeron
128k RAM
3 300G SATA Hard Drives running on RocketRaid 2220 RAID 5


Performance:

Ripping is significantly faster. CPU utilization is around 30% and network speeds sustain well above 5MB. Total ripping time for a movie is around 10-15 minutes and no failures during ripping so far.

Load time of video and music libraries is nearly instantaneous.

In a few words, much improved.


I know the specs my server are less than stellar and maybe I was expecting too much from too little hardware. Even so, the performance of the software RAID was terrible. I just didn't realize how terrible until I switched to the new hardware.

I would recommend to anyone who is running Win 2k Software RAID 5 and having issues that they take a serious look at switching to a hardware solution. And to anyone thinking about setting up their first media server, don't cut corners in an attempt to save money. Had I just purchased this hardware originally I would have saved myself hundreds of dollars in the long run.

 

[rocco]

Micah, out of curiosity, how did you put 5 IDE drives on one computer? Did you get 5 IDE cards? I know that RAID does poorly if two drives try to share an IDE controller, so I have always used SCSI when doing RAID-5. I use two IDE drives as Primary-Master and Secondary-Master when using RAID-1. I've yet to try SATA, but heard it can do RAID well.

 

[Micah]

I hadn't heard about sharing channels killing the speed of the array but I think I can see how it would with the shared bandwidth between 2 drives.

The mobo on the dell has 3 IDE channels and I had 2 drives on each.

I have to admit though, there were other reasons to make the switch. One was the need for OCE. Window's software RAID doesn't support it and I had nearly maxed out my array.

The other reason was the mess of cables. I'd never bought SATA drives before, but the cables are so much smaller and so much easier to work with. Just eliminating 2 of the 5 ribbon cables (1 left for CD-Rom, Floppy drive, and IDE boot drive) and turning 5 drives into 3 has left me with a ton more space inside the case.

 

[rocco]

I hadn't heard about sharing channels killing the speed of the array but I think I can see how it would with the shared bandwidth between 2 drives.

It's worse than just bandwidth, there is a driver problem. It goes like this:

When you need to get to an IDE drive, and the other drive has the channel, the only thing the driver can do is sit and wait for the other drive to be done. Nothing else can run, because if the CPU exited the driver at that point, the system data tables would be in an incomplete state. All your CPU cycles are spent spinning in the driver.

This is what an MS engineer told me when I first setup a RAID on NT4. They may have improved it on 2000, but the engineer seemed to think it couldn't be fixed. SCSI was supposed to be the solution back then, but I'm told that nothing beats SATA today.