Performance increase with Amazon's EBS (persistent storage)

At familylink.com, we have 4 MySQL database systems on EC2 that run that our facebook app, various other social network apps and various websites. I recently switched our disk storage for those instances from the standard EC2 instance disks to EBS (Amazon's persistent storage for EC2) and wanted to share some brief numbers with you regarding performance.

I'm using a simple (yet quite complex) metric to measure the performance increase, load. System load is a number that show how many processes are contending for system resources (usually CPU.) For a more detailed description of load, read this article.

Enough of the talk, here's what I saw when I switched the 4 databases over to EBS:
---Database server #1---
Purpose: 2 moderately used databases
Disk change: 2 striped local disks (raid0) to single EBS volume
Peak Load change: 2.5 to 1
Estimated disk performance increase: 5x

---Database server #2---
Purpose: 2 lightly used databases
Disk change: 2 striped local disks (raid0) to single EBS volume
Peak Load change: 1.5 to 0.5
Estimated disk performance increase: 6x

---Database server #3---
Purpose: 9 lightly used databases
Disk change: 2 striped local disks (raid0) to single EBS volume
Peak Load change: 1 to 1 (no noticeable change)
Estimated disk performance increase: 2x

---Database server #4---
Purpose: 1 heavily used database
Disk change: 4 striped local disks (raid0) to 4 striped EBS volumes (raid0)
Peak Load change: 3 to 1.5
Estimated disk performance increase: 2x

Keep in mind that in theory 2 striped disks are almost twice as fast as a single disk. That's why I say there's a disk performance increase of 2x on database server #3 even though there was no noticeable performance increase (we went from using 2 disks to 1 disk.)

There you go, real-world numbers from real-world sites and servers. In summary, it's safe to say you'll see a significant disk performance increase if you switch over to using EBS with your EC2 instances. In addition to the performance increase, it's a no-brainer that you want persistent storage for your databases. One other huge benefit is snapshots. You can quickly and easily snapshot your database for backup purposes or for testing/reporting you may want to run against your most recent production data. See Amazon's site for more details.

If you haven't yet tested EBS with your systems on EC2, now is the time.