I think it really depends on what you mean by 'a low end PC'.. if you mean a full desktop with an extensible (PCIe etc) motherboard.. I believe the answer is...

I think it really depends on what you mean by 'a low end PC'.. if you mean a full desktop with an extensible (PCIe etc) motherboard.. I believe the answer is... way after you'd ever want to use the old PC[1]. But if you're moving towards the something in the vein of the Raspberry Pi, much sooner. 1. http://ieeexplore.ieee.org/Xplore/login.jsp?url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F9100%2F28876%2F01299692.pdf&authDecision=-203 http://ieeexplore.ieee.org/Xplore/login.jsp?url=http%3A%2F%2...