Mixing RAM sizes works, but don't expect perfect performance.

Yes, you can physically install a 16GB kit and a 32GB kit together (say, two sticks from each) and the system will boot. But you’re not getting the full 48GB in dual-channel mode. The memory controller will run in “flex mode” – the first 16GB from each channel runs dual-channel, the remaining 16GB from the 32GB kit runs single-channel. So you lose some bandwidth, which matters for memory-sensitive tasks like gaming or video editing.

The bigger risk isn’t the capacity mismatch – it’s mismatched speeds and timings. If your 16GB kit runs at DDR4-3200 CL16 and the 32GB kit runs at DDR4-3600 CL18, the system will default to the slower speed. Even worse, if they have different voltage requirements, you might get instability. Always check that both kits are the same generation (DDR4 vs DDR5, obviously), same speed, and ideally the same brand/model to avoid headaches.

Bottom line: It works, but you’re leaving performance on the table. If you’re just browsing the web, fine. If you’re rendering video, buy matched sticks.