According to the Appleinsider website that has been in charge of carrying out this comparison, if we decided to build a Windows-based PC with the same configuration as the Mac Pro, it would cost us a few thousands of dollars more the power to build it if we stick to the price of each component separately.
The starting point here is the $ 9.599 configuration of the Mac Pro, which includes components such as an Intel CPU. Xeon E5 at 2.7 Ghz and 12 Cores with 30MB of L3 cache memory, 64 Gb in four banks of 16Gb each one at 1866Mhz DDR3 ECC RAM, 1Tb of Flash storage over PCIe and to finish a Dual AMD FirePro D700 GPU with 6GB of GDDR5 VRAM each.
In this comparison, components on the PC side such as a Lian Li PC-7B box, which is much more classic and simple than the one that integrates the Mac Pro, a pair of AMD DirePro W9000 GPUs with specifications equivalent to the D700 as well as the same CPU, 64Gb of Kingston RAM at 1866Mhz ECC, 650W Corsair TX series PSU , an Asus motherboard or a 1Tb capacity OCZ Revodrive… these components are equivalent to a greater or lesser extent to what Apple offers on its side.
However the total price of the whole set rises to beyond $ 14 which makes Apple's option for this type of task seem like it is comparatively 'inexpensive'. In addition, it must be taken into account that the PC option does not offer any type of AppleCare or Thunderbolt connectivity, although internally it is more 'expandable'.
More information - The first Mac Pro begin to arrive