Rails + Amazon RDS : latency issues

I have an app whose database is being migrated to amazon RDS.

I experienced a significant drop of performance, due to the latency of the queries between RDS and our server (like 30s of loading time only because of the queries). There is no explicit caching, and the requests could be optimized a bit mo开发者_JAVA技巧re, but this is still more than 10x slower than with a local database.

I this kind of performance drop expected? If yes, is there a way to use a cloud database with similar performances as a local one?

There have been some reported issues with poor performance of RDS by people. Although amazon as far as I've seen hasn't acknowledged these issues.

RDS (which is just a custom version of mysql) uses the ESB for the storage backend, and as I'm sure you are well aware of the failure they just had with that service.

I've read a lot of companies just running their own mysql DBs in EC2 instances becuase it's showns to have more reliable performance.