Compurter recommendation for X4

[NCDave]

I recently acquired an HP8400 workstation/5150 Dual core/4GB/Nvida 1500 (256k) video card. I added Win 7 (as MS is really promising to end XP support this year) 64 bit and Wah-la! X3 doesn't run on it. So, I upgrade to X4, only to discover it doesn't exactly work great on it either. 3D views take f-o-r-e-v-e-r to draw on large files.

Now here's the rub. My other (vector based) 3d cad programs fly on this thing. I have read in some of the posts here that Chief X- uses CPU power over GPU power (that while raster vs vector based thing I suppose) for the 3d draws.

So, from that I'm guessing I need more CPU power for X4? My 8400 will take (2) cpu's & (8) ddr2 dimms. Do I need that 2nd CPU or more ram (or both) instead of a hotter (1GB) video card?

Like ABCHOMESOLUTIONS has mentioned, cost is a major consideration at this time. Even though this workstation is an '06 model, all of the above categories of parts are still available but, I need to spend wisely (and no more than necessary at this point).

Thanks for any input.