View Full Version : Memory of different speeds

04-04-04, 02:52 PM
Right now in my AthlonXP 1800 server I have 256mb of PC2700 RAM. If I get new RAM for my main computer, I'd add that 512mb of PC2100 RAM to the server. Would the 2 different speeds work fine with each other?

Top Hat Theater
04-04-04, 05:44 PM
Yes however the PC2100 will limit the FSB at which the system can run.


04-04-04, 05:44 PM
They would both run at the speed you have the FSB set to... 133mhz if it is at stock settings.

The ram does not run at the speed it is labeled for, it is simply labeled for the speed it is rated to be able to run at. The RAM speed of operation is controlled by the FSB.

So PC2700 ram is rated to run at an FSB frequency of 166mhz at a certain voltage and RAM timings. PC2100 RAM is rated to run at an FSB frequency of 133mhz at a certain voltage and timing. This means that if you mix the two types of RAM, you will be limited by the PC2100 RAM - this is because you have to run both sticks at the same rate, they cannot be set differently.