You can sometimes upgrade a system cost-effectively without replacing the motherboard. The more recent the system, the more likely this is true. The easiest upgrade is always replacing a processor with a faster version of the same processor. Doing that may simply mean pulling the old processor and replacing it with the faster one, although a BIOS upgrade may also be needed. Alas, there is no guarantee that a given motherboard will support a faster version of the same processor or that a required BIOS upgrade will be available, and the rapid advances in processors means that a faster version of the same processor may no longer be available.
The next-easiest upgrade is to replace the processor with a later model from the same generation. For example, you may be able to replace a Pentium II/350 with a Pentium III/850 or, by using a slocket adapter, with a cheap, fast Celeron. When upgrading to a later-model processor, a BIOS upgrade will almost always be needed, and you should check the motherboard manufacturer’s web site carefully to determine which configurations are supported.
Faster processors may draw more current, and the VRMs on an older motherboard may be inadequate to support the new processor. Even if the processor appears to work properly at first, running it for a while may damage both the motherboard and the processor. Always check to make sure that the exact processor you plan to install is supported by the motherboard.
It doesn’t make ...