I'm missing something about adding RAM

[Alonso]

I added a 32 mb dimm to a pc with 16 mb (two 8 mb simms) of RAM already in it. At POST it shows only 32mb of RAM. Is it because I have to fill the other 2 empty simm slots first?

[LJE2]

Some mobo's don't allow you to use both Simms and Dimms at the same time, it's one or the other look in the manual for your board.

[Alonso]

thanks! I'll try to find that but it's not mine ...

[Alonso]

Well, I don't think I'll ever get my hands on this MB manual, and your recomentation seems like the right thing to do... Thanks a lot!!!

[DavidX]

It sounds from your other post that you have one of the early mobos to include a DIMM socket. In that case, even if you can use both SIMMs and DIMMs at the same time, it is not a good idea. As far as I am aware, the earlier mobos did not supply the different voltages simultaneously (SIMMs need 5V; DIMMs need 3.3V). It will supply 5V by default to both SIMMs and DIMMS and the DIMMs (or single DIMM in this case) will eventually burn out.

I have a mobo which will run both SIMMs and DIMMs at the same time but the mobo manual does not recommend it and after reading about the dangers, I immediately removed the SIMMs. I spent too much on the 128Mb DIMM to risk killing it at birth!

I believe that some of the later mobos can supply different voltages simultaneously. Certainly, there are cases where people have successfully used both DIMMs and SIMMs together but unless you know for sure that you can do so safely, it is not worth the risk.

EDIT~ I also remember hearing that some DIMMs are 5V tolerant, but it would be a good idea to get a cast-iron guarantee from the DIMM manufacturer before trying it.

[This message has been edited by DavidX (edited 06-28-99).]