It's not ideal, but you can have them on separated dual(triple, quad) channel. If they are in the same channel it may cause some troubles, system inestability, etc.
– dmbMar 20 '19 at 14:14
So with this CPU it's possible to use them with dual channel and without troubles?
https://ark.intel.com/content/www/us/en/ark/products/88184/intel-core-i5-6500-processor-6m-cache-up-to-3-60-ghz.html
What do I gain if I just buy a brand new single ranked kit or a brand new dual rank kit?
– TudvariMar 20 '19 at 15:44
Possible duplicate of [Can we mix dual-rank and single-rank DDR4 RAMs](https://superuser.com/questions/1153164/can-we-mix-dual-rank-and-single-rank-ddr4-rams)
– K7AAYMar 20 '19 at 15:58
Single ranked matched memory performs slightly better. Dual bank, and quad bank, memory is slightly slower since only one bank can be accessed at any given moment, and there's a minor performance hit in switching banks. Minor.
– K7AAYMar 20 '19 at 16:00