I'm have an instance of X2-64 bit Producer running on a Core Duo E7400 at 2.8 gHz, w 6 GB ram under Windows Vista Home Premium SP2, quite a bit less computer than you describe, and just under the required minimums stated by Cakewalk.
It supports two monitors and a MOTU rack with two 2408mk3's on a Core 424 PCI-E DSP card, 15 to 20 tracks playback, stereo recording, with no pops or crackles, recording at 24 bit, 48 kHz, with instances of Real LPC, Overloud, Studio Drums, Studio Bass, Breverb, R-Mix, and T-racks Opto compressor. Running ~5 busses, 10 sends, looping, editing, and a full screen of console view.
That's as hard as I've pushed it so far.
Been testing it out for about a week, and have yet to lose any data, though I did hang the box once, it refused to save, I gave it some time, it recovered and I rebooted.
From there you ought to be able to do a bit of legwork with benchmarks and get an idea of how your current box will perform. The CPU number I recall was around 1250. The CPU number for my I7 was around 9500.
Hope this helps!
post edited by Jay Tee 4303 - 2014/03/23 10:11:47