1. Four sticks puts a greater load on your IMC than two so if you have an OC, you may lose it.
2. Mixing sticks that came in different packages is a crap shoot. If you buy them and they don't work, tough noogies; if they didn't come in same package, there is no guarntee that they will work together.
3. To get success in this crapshoot ... you want to minimize and differences... that means same speed, same timings , same manufacturer, same version, same RAM module OEM and same size. Again, even if all is a match, it's a crapshoot.
4. Examples ... Up through DDR3, if ya wanted to go all out on memory OC'ing you bot Mushkin Redline. I bought a pair of 8 GB DDR3-2400 CAS 10 and still in use to this day. We were doing a build for a user very similar to mine but he wanted the Corsair Vengeance Pro which had exact same specs and same OEM supplier. About 2 years later he wanted to go to 4 x 8GB and bought 2 more sticks ... same brand and model number but a later version. Didn't work .... Up thru version 4.5 Corsair used the same Hynix modules with 10-12-12-28 timings as Mushkin. From 4.51 and later, they used a cheaper brand w/ 10-12-12-32 timings. Even after reducing the timings for all 4 sticks to 10-12-12-32, they didn't work ... luckily newegg allowed the return and he bought a new pair of Mushkins which had not changed suppliers. With the same OEM , the 4 worked fine but he had to drop his OC by 0.1 Ghz ... eith r pair worked fine at his original OC but w/ the extra load from 4 sticks it was not stable.
Another time way back when had another user who wanted to go from 2 x 1Gb to 4 x 1GB DDR2 (mighta been 2GB can't remeber) . It was well into DDR2's period and DDR3 was not far away ... so options were limited. Mushkin and Corsair had nothing left on the market. So I grabbed 2 GSkill modules for him ... and added them to his original Corsairs. No go no matter what I did ... so he asked me to try getting another pair of the GSkills and they went in fine w/o any adjustments. He told me to keep the Corsairs. My son had a pair of Mushkins with almost same specs ... the guy's Corsair's where newer and had slightly better timings then my son's Mushkins. On a lark, put them in, boosted the timings on the Mushkins to match and the mix match worked fine.
5. I have to agree... with your stated usage, I am not seeing why you are seeing this much RAM usage, however. We normally let employees use their preferred browser and Office Suites. But I was continually befuddled by idential machines with idential OS / software where one was slow and a drudge to use and the other was not. Removing Chrome solved the problem. Doesn't make any sense why 1 box would be snappy a hell and one would be bogged down when both were identical. Reinstalled Chrome and the slowness returned. You might wanna try uninstalling Chrome including all user data and cleaning out registry of all things Chrome and see if that solves the problem.
6. if not using a subscription based Premium AV / malware solution, temporarily disable whatever you are using and try downloading a 30 day free trial of Kaspersky Total Security.
https://usa.kaspersky.com/downloads/thank-you/total-security-free-trial
I often find that it finds things that the freebies miss.
About 5 years ago, my sister-in-law was using the built in Windows thing (today's versions much better but no 100% by any means) ... I d/l'ed KTS and it found 1200 infections ... it removed most of them, about a dozen more required special utilities and the last 4 or 5 had to be done manually. She got tired of the popups so uninstalled it... in 6 months she was back w/ another 500 infections.
Look here and you may be shocked at the protection ratings ...
AnnLabs = 4.5
Malware Bytes = 4.5
EScan = 4.5
BitDefender = 5.5
Trend Micro 5.5
Kaspersky scored 6.0 with 100% detection in the 4 tests. Windows Defender got a 6.0 rarting with 3 x 100% and 1 x 99.9% ...and while 99.9% seems perty good, that means it actually allowed 137 different infections in. So regardless of what ya use, always worthwhile if ya suspect something is 'off' performance wise, to try something else.
