It all depends on the ram.

But what im trying to say is everything has a limit on how much it can do at once. Examples:

You are copying a 4 gb file from one folder to a next and the whole progress bar shows up. Not bad. Doing the same thing 6 seperate instances at the same time, your bottlenecking your harddrive. Its not going to be copying at the same speed. Not very bad, other than an inconvenience.

You have internet explorer loading a page. Not bad. 50 seperate instances of the same thing at the same time. More than likely your CPU ( and your connection) is going to be at 100%. At factory settings this isnt bad, but overclocked your drawing alot of power now and producing alot of heat. If overclocked properly, no worries but if never tested at 100%, lots of potential problems.

You have a few components in your comp and a 300W power supply, not bad. Same power supply but running higher end components and you dont have enough amps on your 12v rail, potential power supply blow outs or failure, and potential ruining of components.

Now as for the ram, you could just get bottlenecked speeds, or you could get overheat issues. Which is what im getting to. The heat issue was what i was hitting on and yes, you could remedy with cooling. but depending on what ram he gets and what his current setup is, he might get a good couple of sticks with heatsinks, but idk what the heat implications for that much data access might be. Or he could go for the water cooling, which is a big expensive step. And if he doesnt get ram with any form of cooling or heat sink, potential heat issues.