Intel Celeron 420

The Intel Celeron 420 offers 1 cores and 2 threads. It drops into the LGA775 socket with a 35W TDP — about 35W per core. Clocks span 1.6GHz base to 1.6GHz boost. Match the socket to your motherboard first; cooler TDP rating second.

Its $5.99 price tag places it squarely in budget territory. PlanMyPC's builder flags compatibility problems automatically and tracks the latest processor deals from multiple stores. Support and warranty service run through Intel, with terms that vary by region. Scroll down for the complete spec table; the builder's compatibility checker will warn you about any conflicts with components you have already picked.