This is the most cost-effective upgrade I could find for my Dell Optiplex XE LGA775 motherboard. The original CPU (Intel E5300) in these units limited the FSB to 800MHz, so I now have double the number of processor cores and 1066MHz FSB. According to my benchmark software the CPU performance jumped from 831.7 to 1866.9 and memory performance from 705.2 to 1065.2 with the exact same RAM. That seems like a pretty good upgrade for ~$16.