rorythedawg

rx 570 no question, GNC is aging much better than maxwell, plus as pointed out by Sorenson, 970 has the weird 3.5g config of actually usable ram and .5gs of trash ram. Where i disagree is with his 1650 suggestion as tbh its not faster and is more expensive, though used prices can vary a lot by region so buy whats best price to performance in the end. 
 
 

Ok, it was the coax TV cable in the basement that was causing the ground loop, i guess that is grounded separately than the House plugs. With that unplugged I have no issue!
 
only figured this out due to this random thread I found when looking into ground loop isolators! https://forums.stevehoffman.tv/threads/do-ground-loop-transformers-isolators-degrade-sound-quality.461707/
 
Shout out to @HenrySalayne for figuring out it was a ground loop!

Gamers Nexus has a pretty in depth video on RAM timings, but this is an extremely complex subject. It has to do with how much time it takes to execute various commands to open rows and such in memory. There's a ton of different timings but the four or five most important are the ones that are indicated on your RAM. That said 2400Mhz is already going to have timings about as tight as you're going to get. They get looser with higher clocks. In that regard, you may be able to OC your RAM, but that's going to require pushing more voltage and I'm just not sure if your board can even handle that. The absolute biggest performance improvement you can make, though, is to get a second stick of RAM. You're running single channel, which means you've got a hard bottleneck there. Dual channel would instantly double your performance, much better than any OC ever would.

To be clear, @rorythedawg meant the board is not intended for OC. A stable OC requires being able to manage and keep under control thermals and power delivery. This is an extremely low end board with cheap VRMs and doesn't even have a VRM heatsink. I can't even find specs on the VRMs phases, but it looks like there's only 6-7 MOSFets (there's two variations of this board, so not sure which you have).

rx 570 no question, GNC is aging much better than maxwell, plus as pointed out by Sorenson, 970 has the weird 3.5g config of actually usable ram and .5gs of trash ram. Where i disagree is with his 1650 suggestion as tbh its not faster and is more expensive, though used prices can vary a lot by region so buy whats best price to performance in the end. 
 
 

My 580 does 2200mhz ram very easily, id guess yours could too.
 
ive got mine undervolted -37mv and running at 1400mhz rn. 
 
Id reccomend just continuing to crank the core clock until it crashes, increase 5-10mv and keep going until your crashing due to thermals (for me this was usually around 80C, though as you get higher in voltage you need lower temps to keep it stable)
 
My 580 is actaully able to clock 1500mhz with +150 or somthing like that mv but I dont have the cooling power for it usually (in winter with the window open i do). 

Also my experience with my 580 has lead me to beleive that anything over 1300mhz basically doesnt change my fps in games or benchmarks. So thats why I decided on 1400mhz with an undervolt. (I was actually able to do somthing like -110mv and run 1350mhz (or something round there) core clock but the voltage was too low for the video decoder so it was stable in games but not watching youtube lol. 
 
Also I'd reccomend using MSI afterburner, gives you control over everything on the card + fan curve

Edit:
heres my numbers for my undervolting, I used Unigen heaven for benchmarks:
-150 mv
coreclock 1350 mhz
FPS: 51.6
Score: 1300
Min FPS: 26.7
Max FPS: 106.3
Power consumtop ~ 102-4 watts
================
-93 mv (this ended up being unstable in long run, but i bet you could do -50 with no issues, i just left my other preset of -37 cause i didnt feel like messing with it anymore)
coreclock 1400
FPS: 52.8
Score: 1331
Min FPS: 27.6
Max FPS: 109.1
Power consumtop ~ 115 watts
=================

I ran an rx580 with a 2200g (basically the same CPU but with an iGPU) and basically didnt get bottle necked (thats a 1060 6gb on nvidia side for performance equivalent) so id definately vote you upgrade the GPU, and then id wait for zen3 for CPU upgrades (even if you only upgrade to zen2 at that point cause the used price drops)
the other stick of ram will also more noticeable than CPU for now.

mobos are much more likely to be faulty than your cpu out of the box. that being said you bought a pretty good mobo so it might be a toss up. if you have any buddies with am4 you could test your cpu and ram on? If not you could order a very cheep am4 mobo off amazon. It should be sufficient to check ram stability. 
 
Even though RMAing is annoying it may be your best bet at this point not to waste money on other gear to test this out. If you do RMA your parts do all of them to be safe. 

Does anyone know what happened to Ivan and if hes coming back or what? I was surprised to see him in the April Fools video after not seeing him or hearing any mention of him for so long. Typically when a staff member has left LTT he makes some sort of announcement/explanation as to why. When Ivan left without any mention of why I assumed that there was some issue between him and Linus and that's why there was no mention. Does Ivan work at float-plane? Is he returning to LTT? Is he just in the video so he can give the line about why he left?