Acer Aspire M3100 desktop, can't seem to run more than 3GB of Ram ...

Hello,

Not sure where you read the specs but this unit has specification indicating a Memory Up to 4 GB DDR2 533/667/800 MHz SDRAM (dual-channel support on four DIMMs)

In reviewing some of the website questions on the acer community I noted:

If a computer has many installed devices, the available memory may be reduced to 3 GB or less.
However, the maximum memory available in 32-bit versions of Windows Vista is typically 3.12 GB.

For the more details on this topic see the Microsoft knowledge base article 929605.

Good day

Hi, I'm new to the Acer Forums. I recently acquired an Acer Aspire M1641-U1521A and am trying to upgrade its RAM to 4 GB, and have had some problems with freezing so far when 2 x 2GB modules are in place (no problems with original slower Samsung factory RAM in place, 2 x 1GB). I'm experimenting with one module at a time in one or the other of 2 slots.

I notice in the BIOS of this machine (not the latest available) is that there are manual settings available for "Top of Memory under 4GB" and "iGPU Frame Buffer Size" (since this has integrated graphics). If your system is capable of 8GB maximum RAM, then your BIOS might display an option such as "Top of Memory under 8GB." If so, you might try setting that value to a low setting, then see how the machine works and what size of RAM it recognizes and can work with as you gradually increase that value over repeated restarts. I may try a similar strategy with my unit. In my case with the integrated graphics (no discreet card yet), I may also try reducing the "iGPU Frame Buffer Size" to smaller values and see if that improves stability.

Good luck!