Question Mixing and matching memory modules: Two sets of 2 vs one set of 4 memory modules

[JayAge]

I am wondering, if there is some performance and/or compatibility issue or difference between use of 2 sets of 2 memory modules and/or one set of 4 memory modules.

To be more specific, my motherboard is the ASUS Prime X299-Deluxe II (LGA2066, Intel Core X-Series), the processor is the Intel Intel i9-9900X (X-series), and the memory sets I am considering are:

• Corsair Vengeance LPX 32GB (4x8GB) DDR4 DRAM 3200MHz C16 Memory Kit [CMK32GX4M4B3200C16], one set of 4, or
• Corsair Vengeance LPX 16GB (2x8GB) DDR4 DRAM 3200MHz C16 Memory Kit [CMK16GX4M2B3200C16], two sets of 2.

Buying two sets of 2 memory modules is significantly cheaper, which makes me wondering if there is some catch in regards to performance and/or compatibility.

Both memory kits are listed on the Qualified Vendor's List (QVL) for the selected motherboard, however a very first line of this document says:

Do not combine DIMMs from multiple kits - even ones of the same make and model. Mixing and matching DIMMs can result in failure to boot.

Is this a correct statement? What if someone wants to upgrade system, let's say from 16GB to 32GB, or what if I will want to upgrade my 32GB to 64GB later on? I cannot buy another same memory kit and be safe to use such memory modules together with those already installed before? Please advise and share your experience, knowledge and thoughts.

 

[alexoiu]

Theoretically, two different kits should work with no issues, even if different specs. Practically, sometimes there are some issues. I would go for the two kits.

 

[13thmonkey]

Generally speaking it is pot luck as to whether sticks from different packets will play nicely together, if sold as a set they'll work, if not sold as a set they might or might not work.

 

[JayAge]

Generally speaking it is pot luck as to whether sticks from different packets will play nicely together, if sold as a set they'll work, if not sold as a set they might or might not work.

What are the odds to buy two sets in one order and to have them from different packets?

 

[JayAge]

Generally speaking it is pot luck as to whether sticks from different packets will play nicely together, if sold as a set they'll work, if not sold as a set they might or might not work.

So you are a risk-taker?

 

[13thmonkey]

15.54%, seriously no idea. It'll work and you'll be happy, it'll work after a lot of fiddling with timings and you'll be content at having beaten the problem or it won't work after a lot of fiddling with timings and you be frustrated. What's your time worth? How many hours are you willing to put into it before the extra $30 seems like a good deal? How many times are you going to go through a bios update and sit there thinking 'I hope it works and I haven't got to do that all over again'.

 

[JayAge]

15.54%, seriously no idea. It'll work and you'll be happy, it'll work after a lot of fiddling with timings and you'll be content at having beaten the problem or it won't work after a lot of fiddling with timings and you be frustrated. What's your time worth? How many hours are you willing to put into it before the extra $30 seems like a good deal? How many times are you going to go through a bios update and sit there thinking 'I hope it works and I haven't got to do that all over again'.

Understood. Thanks.

 

[pchaplo]

Lurker here. Thanks for this thread; learned a lot in facing same decision.