Can I mix different RAM sizes, like an 8GB and a 16GB stick?

Yes, you can run an 8GB stick and a 16GB stick together for 24GB total. The system will enable “flex mode” – the first 8GB on each stick work in dual channel, and the remaining 8GB on the 16GB stick run in single channel. Performance impact is minimal for most people; you lose dual-channel bandwidth on that extra 8GB, which matters for memory-intensive tasks like video editing, but everyday browsing and light gaming won’t notice a difference. Just make sure both sticks are the same generation (DDR4 vs DDR5) and voltage.