The installer will even copy from a mounted ISO file now.
I do the same thing as it is very convenient. No having to locate a disk to install and no worrying if it becomes unreadable. However, I created an ISO for Quake Wars so I could easily install under Windows and Linux this time around, and I was surprised when the installer found the mounted ISO and copied the files from it.
ET:QW seems to be CPU limited under windows on my AMD Athlon 64 4200+, both cores run at 85%+ usage. I'll be interested in how it runs on Linux, it might be a big problem if it doesn't use the dual cores properly but if it runs a lot better then theres something fishy about the windows version. I'll be able to test for myself once fglrx work for me.
Update v1.4 has been delayed until January due to some bugs, one of them being ATI related.
Even with just one core working under Linux, I get almost the same performance under Linux as I do Windows. The difference is like 1-3 FPS in either direction. So I wonder if the extra core will even make a difference. Oh and each core I have is 2.8 GHz.
Quake 4 v1.4 will contain a new threaded renderer that will boost quad-core gaming performance (while ET:QW has already been SMP friendly, these are some additional improvements for systems with more than two cores).