My main machine for years now is a Lenovo ThinkCentre tower with i5-4570 which was $10 from a local guy, also snagged a ThinkCentre i7-3770 at the same time for gaming. I have since put together more powerful machines for gaming but the i5 does its job still, so I keep it. I think the "newest" motherboard I have is a Z390 chipset.