I run a late '08 15" UMBP. 2.53, 4 gigs of RAM. Would upgrading to 6 gigs of RAM increase the performance of my machine when running VMware with Vista? I can't get any answers in any of the other threads. I know about Bootcamp, that's not my question. I have another pc. I use Windows for Lectora Publisher, which is an authoring software for online learning modules. It's basically interactive PowerPoint. It's not a super heavy software, but the content can get heavy with video, sound, animations, etc. My Activity Monitor says I'm using nearly 4gigs when I open VMware and a few of my Mac apps, but don't actually load those apps with content: (Keynote, audacity, acorn, draw it, quicktime) Would upgrading even help since I'll lose dual channel? I know nothing about how RAM benefits machines aside from higher numbers = good.