These days, most DAWs can take all the RAM you through at them, giving you more power and quicker response in a dense mix. This was because the operating systems and DAWs weren’t 64 bit, and they could only allot a certain amount of RAM (memory) to any one program at a given time.
In the “old” days of DAWs – how much RAM you had really didn’t’ matter. In fact there are some strategic things you can do (or upgrade) to optimize your Mac or PC to be a beast of a DAW machine. I did, however, just do some upgrades to it that have helped a lot. In fact, as of this writing I’m still rocking a 6 year old Mac Mini in my studio. The computer you already have is probably fine. Do you really need the most expensive Mac or PC to handle big track counts and lots of plugins in your home studio?