-If you have been shopping for memory you may have run across a speed rating. This is usually notated in NS (nanoseconds). Speed can be really the wrong term but never the less will let you know the time it takes to update or access the RAM. The better the nanoseconds the better the access times. Also take note that is okay to put faster speeds with slower ram on your system but now the other way around. Make sure and not buy slower RAM than what you own.
Figuring Out The Speed On Your RAM
Speed Rating, as mentioned before don't put slower RAM than what is already on your system. You can however get away with faster RAM than what's already on your system. If you need to figure out what RAM you have now look on the SIMM module itself. You may see a -7 or -6 meaning 70ns and 60ns. This can be a real help when going shopping. Don't depend on the catalog of memory modules at the computer store. A tip is a dental mirror that can be purchased at a drug store. This mirror can allow you to look at component markings without taking them out. Cool huh??