For sale is this good original Kingston Turbochip AMD 5x86-133 MHz overdrive cpu for 486 computers that have a socket 3. This is a working item removed from working machines many years ago and has lived in a box until now. It has a good fan and straight pins. The speed will be less than 133 if your mainboard is set for a bus speed less than 33MHz. I also know that one of these can be overclocked to 160MHz by setting the bus speed at 40, but it will cause lockups if the mainboard is VESA Local Bus because it can't handle more than 33MHz. I never got to try it on a PCI board to know if it will work at 40 or not. Best to just be satisfied with 33/133 if you want reliability. Set at 25MHz, the system will report less than 133, but most systems can be changed to 33 for max performance. This cpu will work in many different brands, including certain model IBM's. This one was harvested from a model 77i/s system, but also works in compaq, hp, acer, gateway, dell, etc., along with most 3rd party mainboards.