Slow computer, mismatched RAM?

[Spikkel]

OK, I know this is stupid but I have 2 RAM sticks I got for free, the one is 4GB and the other 2GB. Most of the info on them is not readable anymore but I'm pretty sure they are NOT the same speed or timings.

 

The PC starts up with the 2GB in DIMM0 (black-Channel-A) and the 4GB in DIMM2 (black-Channel-B), but does not POST with the 4GB in DIMM0 and the 2GB in DIMM2.

 

Does this configuration hurt the PCs performance? Would I be better of with just the one 4GB stick of RAM?

[Jarno.]

IT doesnt matter at all. even if its different ram speed then it will run at the lowest speed. But as you might know, RAM speed doesnt effect performance that much. (unless ryzen cpu)

 

in fact i got 12GB of ram in this laptop.  8GB ddr3 by default and i added 4GB DDR3 on top of that myself.

 

Edit: ofc make sure that you got the same type of ram ddr3 or ddr4 etc.. preferably same speed and manufacturer.

[Spikkel]

2 minutes ago, Julian2000nl said:

It works, but yes it does hurt performance.

Is there a way I can measure it? So I can test it with and without the addition RAM.

[Spikkel]

Maybe some more info:

 

The computer is a HP Compaq Pro 6300 Microtower pre-build system, I use it at work for chemical analytical programs running search and integration tasks. I generally have 5 - 6 application open at the same time, with at least one working hard. So I don't know if RAM speed or RAM capacity is more important here...