Question Why has RAM upgrade severely reduced performance of Acer laptop ?

Jun 23, 2020

I have an Acer Aspire 5 A515-51G which had 8GB total RAM (4GB soldered + 4GB in slot). Maximum RAM capacity is 20GB so I recently purchased an 16GB (after being sure that it fits the criteria and characteristics). Now I have 20GB total running in Flex Mode as far as I'm concerned (CPU Z says dual so that's a sign).
My problem is that before changing the slot I run some tests (UserBenchMark and PassMark PerformanceTest) in order to see the difference of Before-After.

PassMark PerformanceTest:
I found out that Memory Write has gotten worse (11676 Before - 7487 After) as well as Database Operations (2938 Before - 2249 After).
Before my RAM scored a 62.2% and After 44.3% (with significantly dropped values at Multi core and Single core scores).
Also while runnig the test I saw memory latency getting a higher value than the previous test.

I don't think that the motherboard is botching the timings / speed, because in CPU Z everything seems good. Before I buy the 16GB Corsair RAM I checked everything to match with the previous one in order to work fine.

Anyone have a clue why my RAM upgrade brought me worse performance? Is it because it runs 4GB+4GB Dual Channel and the rest 12GB Single Channel? Can I do something to minimize that gap?

I will attach photos of my Before-After results in order to understand better.
Thank you in advance!

[PassMark Performance Test][1]
[UserBenchMark Latency][3]
[CPU Z][4]

[1]: View:

[2]: View:

[3]: View:

[4]: View:
Generally, more ram trumps faster ram.
I think your upgrade was a good one.
Do not overthink synthetic benchmarks.
Likely, some of the testing used the non dual channel part of your ram.
What counts is if your pc runs better with more ram.

If you want,
Run memtest86
It boots from a usb stick and does not use windows.
You can download the free edition here:
If you can run a full pass with NO errors, your ram should be ok.

Running several more passes will sometimes uncover an issue, but it takes more time.
Probably not worth it unless you really suspect a ram issue.