Over on our Discussion Boards, design student seandavidson has recently solicited Workstation Help! from his fellow forum members. At 45 posts as of press time, the thread has grown to just under four pages of power-computing expertise (mostly in the first 48 hours, no less), and even though the OP is just about ready to pull the trigger on his dream machine, there's lots to dig in to, especially if you expect to be cranking out renderings on a regular basis.
Longtime member Cyberdemon is especially helpful (and sensitive to the use case), drawing a nice analogy regarding his Macbook Pro: "for the purposes of pumping cad it's kind of like buying a BMW X6 because it's a good 'off roader' sometimes it's worth it to get the Jeep and not care what people think." He also notes that "more ram [sic] will NOT improve multi-tasking while you render. Modern rendering software will eat up 100% of the available cores. That's why your computer will suck at doing anything while you're rendering even if you have 64 gigs of ram"... To which hatts responds:Many rendering packages incorporate a "low priority" feature which will have the rendering job ease up a bit if the user is trying to do other things. Other packages let you set aside whole cores during rendering. (This is a tick in the "RAM doesn't matter" checkbox.)
However if s/he gets into motion graphics or any poly modeling, there are plenty of functions which utilize RAM. Video rendering, dynamics simulation, retopologizing, all use RAM. (This is a tick in the "RAM does indeed matter" checkbox.)