I'm just moving a website from a small instacen to a medium instance as it's a large website (more than 10,000 visits per day) which has been suffering on a small instance.

I thought to try a medium instance as in theory I could simply boot this from a back-up, but this didn't work out and as I've upgraded the site to joomla 2.5 I thought to boot a Joomla 1.6 appliance onto a medium instance wityh over double the RAM.

To my surprise the medium instance doesn't have 3.75 gigs of memory but the same as the small instance, 1.7  If this is because each core has 1.7 that still makes 3.4, so this doesn't computer as 3.75 gigs.

So what am I getting for the extra outlay and will it help me with a site like this. 

One other question is how easy is it to move the elastic IP from the old instance to the new, is it as simple as disassociating from the old one then moving it over (would I lose it in the process).

Thanks in advance