Mixing RAM brands is fine; mixing speeds is risky.

Probably. You can mix different brands of RAM as long as they have the same speed, timings, and voltage. Mixing speeds (say 3200MHz with 3600MHz) usually works, but the faster stick will slow down to match the slower one. That’s not ideal, but it’s stable.

The real gamble is mixing different kits with different timings. Even if the speed matches, timings like CL16 vs CL18 can cause instability or force the motherboard to run at looser timings, hurting performance. Brands don’t matter much—most RAM is made by Samsung, SK Hynix, or Micron—but the specs do.

If you already have mismatched sticks, test with MemTest86 or just see if your system boots and runs memory-heavy tasks without crashes. If it works, fine. If not, buy a matched kit and sell the old one.

In practice: buy the exact same model if you can. Future You will thank you.