Yes, you can combine 2x16GB and 2x8GB into a single system.
Yes, you can combine 2x16GB and 2x8GB into a single system.
You're planning to expand your RAM setup by adding another 2x8GB module, bringing your total to 48GB. This should be feasible depending on your motherboard's support. Your Ryzen 3900X and X570 Aorus Master should handle dual-channel configurations if the slots allow it. XMP profiles may still apply, but verify compatibility with your RAM type. Ensure you check the specific slot requirements for dual-channel operation before installing.
Yes, it would remain the same brand and performance, only using two 8GB sticks instead of two 16GB sticks.
The same speed should work. I've used 48GB in my system before without issues (though it ran with an i7 9700 and RAM capped at 2400). Just arrange one 8GB stick and one 16GB stick in each channel, alternating between them. You're likely already using dual-channel, so the new sticks fit perfectly into the available slots and you'll have the correct setup.
Only when they come from the same batch does the RAM match. Others vary in some way. Each batch has its own MIC, and there are options for single or dual rank. What is the brand and model of the RAM?
I’m new to using XMP on kits with varying sizes, but it seems possible—just give it a try. If the timing and frequency settings align between the two devices, there’s no obvious barrier. Still, I haven’t handled kits of different capacities that support XMP before.