Here's something that will truly test this...
Capture packets with Wireshark while playing your game, and have all computers on the network talking (sharing files, downloading, etc.). The goal is to build the biggest .cap/.pcap file that you can, I would say at least 750MB for a decent test. This may take all night. A good comparison is a customer of mine has a saturated (99% all day) T1 circuit, all traffic going through a proxy server, 3 satellite offices via s2s VPN tunnels, and it built a 16GB file (yes, GIGA!) in 24 hours. I broke it down to 500MB files, and that will address 1.1GB of RAM, and merging another file, it will use all of RAM and some of swap, then the screen goes grey, then CWAAASHHH!!! Reboots!lol
I will post back with the results of my own test, as I have not paid too much attention to swap during loading the file.