Is it okay to mix different RAM sizes and speeds when upgrading?

It’s true, it may degrade performance a bit, but it won’t cause any serious damage. Just be aware that running mixed RAM can sometimes lead to slower load times or crashes if you're really pushing your system. But for everyday use, you'll likely not notice much difference.

Mixing RAM can lead to stability issues when overclocking, but since you're not pushing it, you should be in the clear. Just remember that if you want to use the XMP feature to overclock, having mismatched sticks might lead to instability. Otherwise, go ahead with your upgrade!

Mixing different sizes and speeds isn't ideal but it sounds like you're not looking to overclock, so it should work out just fine for you. Just make sure your new sticks fit well with the existing ones in terms of speed and voltage. Worst case, they’ll run at the speed of the slowest stick.

Honestly, it won’t damage anything, but it’s not the best setup if you're looking for optimal performance—especially if you're considering overclocking. If you keep everything at the stock speed, you should be fine with mixing sizes and speeds, but just keep in mind you may not get the full potential performance from the faster sticks.

Yeah, the main issue arises if you're trying to overclock or use XMP profiles. If you're just running the RAM at its default speed (like 2133MHz, as you are now), mixing sticks won’t hurt anything. You’ll be fine running them together, just keep everything at that baseline speed.