It might not be your computer or your internet connection speed. But there are other parts to the ‘internet’ puzzle. For example, I’ve been reading that some folks in Europe who use Telekom as their ISP having been having problems. And I’ve had personal experience with another provider here in the US who throttled my internet speed at their convenience. Using a VPN can help to resolve both situations.
Also, when you say “20 gigs of memory” that tells me you don’t have a standard RAM configuration. RAM comes in multiples of 2GB (1GB if you want to take a trip in a time machine 
) And it’s typical to use either 2 or 4 DIMM’s. How do you get to 20GB?