Ubuntu Linux uses the Mdadm utility to manage software raid devices. This isn’t as fast as having a hardware raid controller, but it’s certainly cheaper (free!) and more convenient. I had a few identical drives laying around, and I’m in the middle of building an HTPC so I figured this would be a good opportunity to toy around with it. The machine I’m using in this test has an Athlon 64 X2 processor @ 2.4ghz and 2GB of DDR400 ram running on an ASRock 939Dual-SATA2 motherboard.

For my first test I used two ancient Western Digital WD400BB 40GB 7200RPM PATA drives from 2001. Initially I connected the two drives on a single PATA controller:

This results in very low performance, due to the limitation of only one device per channel being able to process instructions at a time. In this configuration, two drives isn’t really any faster than a single drive. I doubt many people are using PATA drives anymore, but this is something to note if you want to give an older machine some extra kick. So I tried with each hard drive on its own PATA channel.

This resulted in a great improvement in sequential read/write operations. Nearly 100MB/s for reads and writes! Rather impressive for two eleven year old drives.

I also had two Western Digital WD800JD 80GB 7200RPM SATA drives from 2006 laying around, and figured the performance could only be better with these given the faster interface and improvements in hard drive technology during the five years separating the drives in my test.

The newer drives read rate is about 20% higher than the old setup, however write speed did not change much. Still, 20% is a noticeable improvement. This configuration is quite enjoyable to use, programs are responsive and games load very quickly.

It’s obvious that there are performance gains to be had with RAID0, whether it be implemented in software or hardware. Software RAID with Ubuntu is very easy to set up however, and avoids a number of the issues with hardware RAID even if it does lower maximum performance slightly.