I'm putting together a budget AM4 system using mostly inexpensive second-hand parts. I accidentally bought a Corsair memory kit with 2×4GB sticks instead of 2×8GB. I can cheaply purchase two more 4GB sticks, giving me 16GB in a 4×4GB configuration, and my motherboard supports four DIMMs. Are there meaningful drawbacks beyond having less room for future upgrades? Would it be better to sell the current kit and buy 2×8GB instead?
4 Answers
AM4 platforms are generally quite stable with four DIMMs. Try to buy the same kit or at least modules with matching specifications. If two sticks are rated for 2800 and the other two for 3000, they’ll most likely run together at 2800 unless you manually find a stable setting. The fact that both are Corsair Vengeance LPX helps, but the exact timings and voltage still matter.
There shouldn’t be a noticeable real-world performance difference between 4×4GB and 2×8GB at the same effective speed. Four sticks can sometimes perform slightly differently depending on memory rank, but any difference is usually only visible in benchmarks. Go with 4×4GB if it’s significantly cheaper; choose 2×8GB mainly for easier future expansion and simpler compatibility.
Four DDR4 sticks should work perfectly well on AM4. Ideally, use modules with the same speed, timings, and voltage. The main potential downside is slightly less overclocking headroom compared with two sticks, but that generally won’t matter at normal settings.
The system will normally run all the memory at the settings supported by the slowest or least capable stick. Four modules can make very high memory speeds less reliable, especially if the kits are mixed. Around 3200 MT/s is usually straightforward on compatible Ryzen systems, while speeds such as 3800 may require more tuning.
The two sticks I already have are rated at 2800 MT/s, while the pair I found is rated at 3000. Since they’re both Corsair Vengeance LPX, I’m assuming the faster pair would drop to 2800 automatically.