Upgrading RAM

[Dicka1]

I just purchased an 8 GB RAM module to replace the 4 GB module that was there. I removed the 4 GB module and installed the 8 GB module in its place. That leaves me with the 4 GB module. There is a second slot where I could install it.  I have not done that because I fear incompatibility issues. The instructions from the supplier tell me to install the larger module first and make it the RAM. I have done that and am impressed by the increase in computer speed over the last two days. My choice is to recycle the 4 GB module or to reopen the computer and install it in the vacant second slot. In theory I would then have 12 GB RAM. Would you advise doing the latter? What could happen if the two modules are incompatible?

[wb2001 · Accepted solution]

@Dicka1,

You handicap the answer:  What did you install?

1) DDR4 2400 is standard.  It you installed DDR4-2666 there would be a slight increase in speed.

2) Installing the 4 GB (2400) would cause the possible 2666 to revert to 2400

3) Dual channel memory implies matching pairs. It would operate in dual mode for 8GB (4 GB per module) channel A & B, then revert to single channel for the last 4GB segment.

[Dicka1]

Thank you so much for your thoughtful advice! I will recycle the extra RAM.