

I was wondering that too
I have personally tried to upgrade it, don't believe the lies and unhelpful customer service scripts, aspire 4 a515-45-r74z only has ONE memory slot, compatible with a max of 16gb.
Only one extra slot on mine. I added another 8GB to match the size on the mother board. Still trying to figure if it's better to max it out by adding a 16GB. Can't seem to get a straight answer to that.
Bearco,
If your laptop has 8 Gigabytes and you added a second stick of 8 Gigabytes, THEN you are good to go.
You have 16 GB or RAM operating in Dual Channel. (Even if it is not the MAX allowed in your PC.)
by comparison; my laptop has 4 GB on the board and 4 GB in the (only) RAM slot. I installed an 8 GB Dimm. I now have 12 Gigabytes, an improvement to be sure, but perhaps NOT Dual Channel. I had the 8 GB RAM dimm, that I took out of another computer. I did not think it worth the trouble to buy a 16 GB stick of RAM to make 20 GB (my MAX) but still not Dual Channel.
Again, you are Good to Go! Cheers.