RAM single and dual. Can they work together?

Question

laptops

Bought an extra 4 GB RAM for my laptop. It should have been 8 GB. (2 dies of 4). Only when I got home, I saw that the laptop sees only 4 GB. One plate Single, and the second dual. Is it possible to somehow use both, or do I need to buy the same type?

Answer 1

Does the laptop have 8gb?
4 shows BIOS or Windows?

Answer 2

Single and Dual means that the memory chips are soldered on one or both sides of the bar, 4GB Single will be soldered with 512MB chips on one side, and Dual on both sides (or a high bar with one dialed side but in two rows) with 256MB chips, which is very critical for laptop or specific motherboard whose chipset is not capable of reading the memory typed in 512MB chips. For example, 2gb Single DDR3 is loaded with 256MB chips on one side and works great in tandem with a 4gb bar typed on both sides.
In your case, as I understand it, one bar is typed with 512 chips and it does not work, but typed with 256 chips - it works. The culprit here is an outdated chipset.