With motherboard availability and bus speed compatibility, you can easily mix 4GB and 8GB RAM together. If you want to use 4GB and 8GB RAM together, buy both RAMs of the same bus speed. But before purchasing the RAMs, confirm how much bus speed your motherboard can support. There’s more that needs your concern before adding two different RAMs. Asus Crosshair VII WiFi X470EVGA 3080 FTW3 Hybrid. i7-2600K 4751MHz 1.44V (software) 1.47V at the back of the socket Logitech G610 Orion (Cherry MX Blue) with SteelSeries Apex M260 keycaps BenQ Zowie FK1. 8+8GB DDR4-2400 18-17-17-39 2T + Crucial MX500 1TB 2.5" SATA SSD, 128GB Toshiba PCIe x2 M.2 SSD (KBG30ZMV128G) gone cooking externally, 1TB This effectively means that almost any combination of DDR4 DIMMs will work - but it will pick the lowest common standard timing and speed, which means that for intensive applications such as games, performance may really suffer (i.e. 16 GB of matched RAM will be much faster than 32 GB of mixed ram), but for bloated entreprise software, at few If there are 4 RAM slots, then you're all set. You should ideally already have your two 8gb sticks set as dual channel, each channel running 8GB for 16gb total. Slot in your new sticks and it'll be 16gb each channel for a total of 32gb. For a while now, the golden standard for gaming has been 16GB of RAM. Even the higher clock speeds are relatively inexpensive—a 16GB kit of 3600MHz is on sale for about ~ $75 at the time of writing—and if you’re willing to sift through the aftermarket, cheap second hand RAM kits are fairly common. A 16GB kit will run pretty much every oobymach. Yes it is possible to mix different ddr4 kits, I just recently tested my 16gb (2x8gb samsung b-die) and 32gb (2x16gb hynix) kits together and had 48gb of 2133mhz ram (I couldn't get it to run any faster than that, it wouldn't post at all with super loose timings at 3400mhz and both kits are rated for 4ghz+). I believe you can just make sure your mobo supports such individual sticks. 32 gigs in a single stick is not very common. I think you can but consider just buying 2x16GB sticks at a higher spees and using just them if you have a Ryzen CPU. Ideally 3200 or 3600MHz. You don't need to match two sticks of 16GB if you aren't going to use all of that, but a 16GB and 8GB stick would give you more consistent performance. Hi, thanks for posting on r/pcgamingtechsupport . Please read the rules . For maximum efficiency, please double check that you used the appropriate flair. Layout and guide here. Short answer, yes, you can do that. It's best to install RAM in pairs. It's also best to put identically sized RAM in the paired slots, which you noted you're going to do. The maximum amount of RAM that iMac will recognize is 32 GB, and you'll still be within that. This will definitely happen for those using just 8GB RAM, so if you're maxing out on 8GB RAM, upgrading to 16GB will be a huge boost, but going from 16GB to 32GB won't give you that much better YOafx.