You conveniently forgot that OP clearly stated "FEA/CFD", narrowing down the appliction area and available solutions more than sufficiently
I worked for a major CAD/CAM/FEA software maker and they have only recently added distributed computing capability to their software and it is still very limited in its capabilities. They still do not use GPU capabilities beyond rendering. While I know from my erstwhile colleagues who are now working for another major FEA/CFD maker, and their software has cluster computing capabilities for many years now, their software utilizes GPU too. So I agree with the its important to understand the capabilities/requirements of the S/W before you procure the hardware.