Difference between blue and black memory dimms. For best performance you need to install memory beginning with the first slot, which is usually a white tab, i think. H61 Desktop Computer Mainboard Motherboard 1155 Pin CPU Memory that matches in speed and size in either. Motherboard memory slots blue black . This means that colored slots are just pure marketing. The black slots are pci express x16 (wired as x4) connector and the blue slot is pci express x16 card connector primary video slot. If you have a pc, you will find the ram slots on your motherboard near the cpu.there will be two, three, or four slots where you could install ram. Problem is run this 4 slots memory in dual channen in standart overclock mode 3200mhz. We can now push memory capacity up to 2tb with the new platform with supporting cpus. The color on the dimm slots themselves reflect what type of channel they are if you have four slots and for example two are blue and two are black that means you have a d