I ran the Black Death track on my rig and to my surprise the result wasn't at all bad, taking into account that my rig is about 6 years old: MSI K9AGM2-L mobo, Athlon X2 5000+ CPU, 320 GB SATA HDD, 4 GB DDR2-800 RAM, nVidia GT630 2 GB vid card, W7 Ultimate x64. All settings- planes etc- on "high", roads etc enabled. First few seconds screen was simply white, blue, black and yellow, then ground details and objects appeared, a few seconds later the camo schemes on the planes popped up, next was the full detailing of the ground- trees etc plus full colours. Track ran with a few occasional microfreezes, but apart from that OK- certainly something one can live with. The CPU is probably the limiting factor as it is only dual-core, but as it is close to the maximum the mobo will accept (Athlon X2 5200+) there is probably little to be gained by buying the 5200+. RAM is at mobo's maximum. Vid card is a fairly recent upgrade- before I installed CloD- driver is the latest, 314.07.
Will build a new rig this year, using the GT630 as it's almost brand-new. This will hopefully run CloD at its best.