We host a Magento webshop hosted by Amazon EC2, and we have speed issues. We're currently looking at moving to another provider. We found one hosting provider where we have a test account now. Speed is better. They use memcached, and this made me wonder how that will improve things for us, if we use that on our servers. 

I've read that memcached caches database tables, but I understand that it is installed on the webserver, not the database server. 

**Are there any downsides or risks when using Memcached?** 

Will this have unforseen effects on other applications, besides improved speed? How about RAM - will we need more memory for it to work properly? Now we have 1715MB RAM (strange number but this is what it reports).