Problems with CS:S

I bought CS:S a few days ago, but seem to be having some probelms with it. It seems extraordinarily laggy sometimes -- a lot of the time, actually, even if I make my own server with bots on it. It lags on plenty of other servers too, so I thought perhaps it's a problem with my hardware, but then a few servers it ran fine on. I don't know what's going wrong, so anyone have any advice?

What're your computer specs and what is your connection speed?

Some servers may have worked faster than others because they are close to your area.

What're your computer specs and what is your connection speed? Some servers may have worked faster than others because they are close to your area.

3.0 Ghz
1 Gig of ram
128 MB Graphics Card

Cable modem -- roadrunner.

Well, I figured out that it only does the lagging thing with some maps, if that helps. FY_ICEWORLD almost never lags.

*gets in diagnose mode*

Go to options, keyboard, advanced. Turn on developer console.
Then go into console (~) and type:
net_graph 3

Tell us what your fps, choke, loss, and ping is when you're lagging. Also, how many people are on the server, and how many are on your screen?

Those specs shouldn't lag, I wouldn't think. Perhaps something of yours is faulty hardware wise or you have too much porn spyware? .