Does RAID0 Really Increase Disk Performance?

Introduction

RAID0, also known as data striping, can be used if you want to increase your PC disk performance, being recommended to high-end PCs. It works by accessing two identical hard disk drives in parallel, so in theory it doubles the data transfer rate between the computer and the hard disk drives. We were very curious to see if RAID0 really increases the hard disk performance and how it reflects on PC overall performance, so we set a RAID0 system, benchmarked our system and compared it to the same system with just one hard disk drive installed. We set our RAID0 with several different stripe sizes, from 4 KB to 128 KB, to check which configuration would give us the best performance. Check it out.

We have already published a full tutorial on how to setup a RAID system. In this tutorial we explained how RAID works and how to setup your own RAID array. Please read this tutorial if you need more technical background on RAID.

Our test procedure consisted in formatting our single hard disk drive and installing all the software described in the next page, running them and writing down the results. Then we installed a second identical hard disk drive, configured the two hard drives as a RAID0 array using the default stripe size, which was 128 KB, and repeated all the process. We did the same thing over and over again, decreasing the stripe size at each run, until we reached the minimum possible stripe size, which was 4 KB.

We measured two aspects: the hard disk drive transfer rate and the system overall performance. While the first aspect tells us if the hard disk drive performance really increases with RAID0, the second aspect will tell us if this increase in disk performance (if any) will be translated into a higher system overall performance, i.e., when you run daily programs like Microsoft Office.

We played with stripe size because this is one of the biggest questions users have when assembling a RAID0 system: what stripe size should I use? Which one provides the highest performance? We will provide some thoughts on this issue as well.

Enough talking, let’s go to our benchmarks.