I currently have 16GB of RAM rated at 4400 MT/s, which is 2200 MHz actual memory clock. I found another 16GB kit rated at 2400 MT/s for around $50. I would add it rather than replace my current memory, bringing the system to 32GB total. I understand that all of the memory may run at the slower kit's speed, but I'm wondering whether the extra capacity is worth the performance drop until I can find a better deal. Is mixing these kits a reasonable idea, assuming they're compatible with my motherboard?
4 Answers
It will often boot with mixed sticks, but stability isn’t guaranteed. The system may fall back to standard JEDEC settings, and enabling XMP could cause crashes or prevent it from booting. You can sometimes tune the timings manually, but that’s only worth attempting if you’re comfortable troubleshooting memory.
I’d probably wait for a matching kit. Mixing the memory will usually make the system run at the slower speed and looser timings, so dropping from 4400 to 2400 MT/s is a significant hit. A matched 2x16GB kit would be a better long-term upgrade, especially if you care about gaming performance.
For gaming, I’d prioritize faster, matched memory and wait. For productivity, virtual machines, editing, or anything that regularly exceeds 16GB, the extra capacity could be worthwhile despite the lower speed. A 32GB 3200 or 3600 MT/s DDR4 kit would be a much better target if you can find one at a reasonable price.
$50 for 16GB at 2400 MT/s isn’t terrible, but it isn’t an amazing deal either. Before buying, make sure both kits use the same memory generation and that your motherboard supports four DIMMs. If your current memory is DDR4, another DDR4 kit may work; DDR4 and DDR5 cannot be mixed.

That makes sense. I’ll look for a matched 32GB kit around 3200–3600 MT/s instead of jumping on this one.