Socket 478 was used by Socket 478 Celeron, Socket 478 Celeron D, Socket 478 Pentium 4 and Socket 478 Pentium 4 Extreme Edition CPUs. Keep in mind that these CPUs are available for other sockets as well, so we are talking specifically about socket 478 models here. In order to know what is the fastest CPU you can install on your motherboard, you will need to know what is the maximum FSB clock rate your motherboard supports. Typical values are 400 MHz, 533 MHz, 800 MHz and 1,066 MHz.

To make things simpler, we compiled the table below. At one side you have your motherboard FSB and on the other which CPUs are supported. Pay attention because some newer motherboards supporting 533 MHz and above can’t provide a 400 MHz FSB. You need to check on your motherboard manual if this is your case – if it is, your motherboard doesn’t support the installation of Socket 478 Celeron CPUs.

* Not all motherboards support Celeron D and Pentium 4 CPUs based on ”Prescott“ core (all Socket 478 Celeron D CPUs are based on this core). This happens because of the new power specs required by Prescott-based CPUs. So take a careful look at your motherboard manual to find out if it supports Prescott-based CPUs (look for ”Prescott“ and ”Celeron D“ – if it supports Celeron D this means it supports Pentium 4 ”Prescott“ CPUs) or not. Here you can find a full list of Pentium 4 CPUs that are based on Prescott core, which may not work on older motherboards. On this same tutorial there is a list of Pentium 4 CPUs based on Willamette and Northwood cores, which work on all motherboards with the proper FSB.