Stick with 2x32GB for dual-channel.

Yes, both get you 64GB, but 2x32GB is better for dual-channel performance. Four sticks (4x16GB) often force the memory controller to run at lower speeds or switch to single-channel mode on consumer platforms.

Most consumer CPUs (Intel Core, AMD Ryzen) only support two memory channels. Populating two slots runs dual-channel cleanly. Fill all four slots and the memory controller has to work harder, which can cause instability at high speeds or force a clock speed drop. You might lose 5–10% performance in memory-sensitive tasks.

The only reason to go 4x16GB is if you already own two 16GB sticks and want to add more, or you’re on a workstation platform (Threadripper, Xeon) that actually benefits from four sticks. For a normal desktop, 2x32GB is simpler, faster, and less likely to cause headaches.

Don’t overthink it unless your motherboard manual explicitly says four sticks run at the same speed as two.