I'm on 16GB here. I have both Linux and Windows 7 (x64) installed. I only have Windows installed for playing modern games every so often though.

On Linux, 16GB RAM allow me to actually run 6 virtual machines simultaneously (I use VMware Workstation): Debian 32-bit, Debian 64-bit, Windows XP, Windows 7 x64, Mac OS X 10.6 and Mac OS X 10.8, where I build and run my projects (I don't have any other use for the VMs, so they don't get too much RAM.)

I also use a tmpfs mount point (it's an adaptive RAM disk, and I've set it to 12GB) to build software entirely in-memory (I use Gentoo Linux, and since that builds all software from source, this speeds the process up by a lot.)

So yes, 16GB RAM is more than plenty for your purposes. You should be able to run Windows 7 inside Linux and also give it plenty of RAM to work with.

Here's my rule of thumb -- I run machines with however much RAM they come with, and the first time it becomes an issue, I find out the maximum amount of RAM they'll handle and I max them out. Both my workstation and my server max out at 8 gig, so that's what they have.

The absolute worst thing you can do when it comes to VM performance is over allocate your RAM. Swapping RAM is already slow, but when you do it on a VM it slows down both the host and the virtual client, which slows things down even more. Get a couple of VMs swapping and you'll bring your host to its knees.

I'm running Windows 2003 server w/8 gigs on RAM. On top of it I'm running the free version of VMServer, and in it I have three virtual machines running -- a mail server with 512k of RAM, a Domain Controller with a gig of RAM, and my web server which now has 3 gig of RAM. That's 4 1/2 gig of RAM for virtual machines and 3 1/2 gig for the physical host. Three months ago I installed a 128gb SSD drive in the server and all the virtual hosts run off of it. Between those two things, my VMs fly.

I run 4GB on an intel duo core 3.4 ghz machine. Lately been running Centos 4 in vmware while doing other work. I do things like leave a long compile running in vmware in the background while playing old games with no problems.

I would imagine though that running a fancier OS in VMware with a nice GUI and all would probably bog down things quite a bit more.

4g in the desktop, 1g in the laptop.

I'd have to upgrade the mobo (or actually replace the laptop) if I wanted more but I don't seem to need more.

I ordered some RAM off Newegg. I should have 16 GB of RAM. I think that will be enough to run a virtual Puppy Linux machine at all times, and allow me to ensure that I am testing Cyberganked in a Linux environment. But more, I'd like to eventually make the switch completely to a Linux system.

How much RAM are you guys running? I'm going from 4GB to 16GB. I've got 16GB on my computer at work. As much as I use virtual memory, man, it just doesn't appear to be anywhere near as quick as the real deal.