Additional Notes: For best performance, fill both memory slots, installing an equal memory module in each slot. The likely technical explanation here is that your MacBook (motherboard) supports dual-channel architecture and thus requires two identical memory modules. Benchmarks suggests that it gives a 5-10 percent performance boost. Empty RAM slots. Open the Task Manager and go to the Performance tab. Select ‘Memory’ and under the memory graph, look for the Slots used field. It will tell you how many of the total slots are currently in use. In the screenshot below, the system has a total of 2 slots, and one of them is in use. The motherboard I am choosing is the Asus Maximus IX Code. It is dual channel compatible. There are 4 memory slots on the board. I want to have a total of 32GB or ram. Is it correct that I would be better off to use two slots with each stick having 16GB instead of filling all 4 slots with 8GB sticks? The only thing to consider is if you plan on using Dual Channel with your RAM. Alot of MOBOs that support dual channel require pairing of course, but if you fill all the slots it bumps the FSB down! So read very carefully on what your board says about this. This thread has been Locked and is not open to further replies. Mixing RAM modules with different memory specs often causes problems with system stability. If the memory you wish to install is faster than the PC’s existing system memory, consider removing all of the old memory sticks and replacing them with new ones, especially if the motherboard can support the faster speeds.