I just bought an Atom-based mobo, and I notice that one issue is that FF starts up in 6 sec or more, but this is with all possible hacks that I know of. I compiled FF several times and different types, like Icecat, swiftweasel, pgo, etc. Nothing will get it under 6 sec. I've also tried everything suggested here:
http://bbs.archlinux.org/viewtopic.php?id=73904
And, several preference-based options, but nothing helps. I was thinking maybe to install gcc 4.5 and optimize for Atom, but somehow I don't think it's gonna do much.

I know 6 sec in not bad, I've heard people get 10-15 sec, but go-oo opens in about 2 seconds. And, on my current desktop both go-oo and FF open in 1-2 sec. So, this makes me wonder...

Anyway, this is running salix64 13.1. Any suggestions are welcome. I'll probably try gcc next.

I know that disabling extensions will help, but I actually need most of them.

Have you tried turning off "check for updates"? I find that turning it off speeds up the start time. Also you could have Firefox autostart when your desktop/wm loads.

Or use a preload daemon like readahead or sreadahead to load it into the cache when your hard drive is not running during boot.

Do you use a local or remote start page? If the latter, perhaps accessing it is what takes time. Netbooks are under-powered: that could be the problem.

Thanks for the replies, well I've tried all of these suggestions, except readahead, and they do not help. Uninstalling some extensions has helped, and it is now 5 sec. Opera starts in 3 sec. And without any extensions, FF starts in 4 sec. So, I guess this is good enough. I suspect this is because the memory is single channel, and RAM transfer rate is low. It is still strange that go-oo opens in 1-2 seconds.

I wonder if I can somehow make FF into a large single binary like a static build, like the opera binary. This might help.