So the cause of the latency when monitoring is my soundcard?
Hmm.. Better start saving some money for a new soundcard...
Not always. But it's one of the first things I would consider.
Note that, when trying to figure out the cause of latency, it's important to know
when you get the latency. On recording? On playback? When monitoring what you're recording in real-time? Monitoring in real-time with effects?
My friend can record raw tracks pretty well. But when monitoring through headphones, while he is recording, that's when he gets latency. And that is when (good) ASIO drivers are really important. Especially with effects on the track.
So, in summary, just get a good sound card that has ASIO drivers. Most cards that are meant for recording will have them (M-Audio 24/96, the ones listed in this thread, M-Audio Delta 66, etc.).
And avoid USB interfaces if you can. FireWire is a much better option. PCI is the best. PCI-Express is even better since it's newer and will replace PCI soon.
I'm kind of rambling here, but just thought I'd throw some useful information out there for if/when you consider a new sound card.
If you get latency while monitoring, then get a good sound card with ASIO drivers should take care of it. Although, if your CPU is a total piece of crap then that could be the problem as well. Note that mine is only an AMD 1.2GHz and I get no latency. So if it's better than that then I will bet it's an issue with your drivers.