Maybe this is relevant:
Ok, living at the parents house temporarily...................anyway, I setup my mom's new computer yesterday.........emachine that she got at a Best Buy Christmas sale for $150. I just hooked everything up, uninstalled all the bs that comes with a new pc (aol, trial virus protection, etc.), and installed my usual free virus scan and spyware stuff.
Since my recording gear is all packed away in the attic, I started getting an itch to record a couple of tracks in Cubase, even though I knew I would'nt be able to do much on mom's low buck emachine. Mom won't mind a little Cubase action on her pc.

It's a Emachines T3406, 2.9 Celeron D, 256 mb ddr, 7200 rpm 2 mb cache 80 gb hard drive, onboard sound and video; a pretty decent internet machine but pretty light on ram for my taste.
So, I have nothing to record with but my acoustic........zilch. I scavenged an electret mic element from an old usb dictation mic and wired it up to a mini plug. Desperate times call for desperate measures. I grabbed the ASIO4ALL driver so that maybe I could get some decent latency. I used it in the past, before I got a decent ASIO sound card, so I was familiar with setting it up..........figured maybe I'd get 10 ms latency anyway. Plugged in the mic, setup the bus's in Cubase, set the latency to 10 ms. Not even a glitch so I gradually dropped it down and ended up with 2ms. Damn, not bad. The onboard sound even supports 24 bit 48khz recording.
I remember someone in another thread talkin up the Celeron D's a bit so I figured I would give it a little test. Surfed over to RawTracks.com and grabbed a 22 track sample of the product. I imported the tracks, hit play and everything ran smooth..........2ms latency. Ha! I could'nt believe it. 24 tracks (2 tracks copied) @ 2ms latency, not a glitch in site. How about 48 tracks? Not a problem either.
Now the real test.......some plugins. All I have on hand at the moment are the standard Cubase plugs, but should suffice for a little testing. So, I drop back down to 24 tracks. Pile on a combo of 24 plugs (one on each track) including reverb a, reverb b, roomworks, mod delay, and double delay. The cpu meter is pegged as I hit play and it sounds pretty nasty. I ended up bumping the latency way up to 23 ms. But hey, it's running smooth although the meters are running a little slow.
To sum it up........it's a cheapo T3406 Emachines pc, Celeron, 256 mb ram, 1 hard drive, onboard sound and video, Cubase SX 3, no special daw settings, virus protection running, and spyware protection running. 48 dry tracks @ 2ms latency and showing 30-40% cpu usage. 24 tracks and 24 reverb/delay plugins running @ 23 ms latency and showing about 75% cpu usage. Able to track at 2ms latency. All this on mom's cheapo Emachines.
Hell, it probably smokes my daw.