According to your comments though, you'd have been just as well served with a regular VPS at a regular VPS host - you wouldn't have wasted time to found out RDS is slow, and you wouldn't have issues with slower than usual disk IO on EBS.
My point about physical was just another common optimisation for performance critical DB servers, you could probably get close to bare metal speed with the flexibility of virtualised by using a "single VM on hardware" model that some providers offer now.
My point about physical was just another common optimisation for performance critical DB servers, you could probably get close to bare metal speed with the flexibility of virtualised by using a "single VM on hardware" model that some providers offer now.