I want to be able to reuse as many components from my old PC in this new one for mining rig. I don't use the Old PC for any purpose at this point.
Can I use an Intel Pentium 4 Processor 3.0 Ghz with an ATI Radeon HD 5870 GPU?
Another point here. The ATI Radeon HD 5870 GPU requires a latest motherboard. But will an Old CPU go on the processor sockets on the latest Motherboards?
Cpu's only go into sockets they were designed for, if that pentium 4 is a socket 775 model you can purchase motherboards that will allow you to use a pci express graphics card with it. Any cpu that is compataible with a pci express equiped motherbaord can be used for mining