Hello, it is difficult to say if the issue is the VRM design or the board that you received may have a different issue. Out of curiosity, what CPU are you running and what OC have you managed?

Well there are many factors at work. Your old powersupply actually had more than enough power, the new one might just have better ripple surpression and thus delivering cleaner power to the VRMs.
 
First of all 81 is perfectly fine especially for the 12-Core variant on just an AIO. They can take a lot (104C if  temp limit is raised) since you don't put the same load on the chip 24/7 as benchmark/stresstest tools like prime95 do all the time. If you hit 5.1Ghz that's pretty damn good. But you don't clarify if this is only CB R15 stable (benchstable) or rockstable.
 
Anyways to give you a quick guide for the platform.
 
Raise Vccin to 1.95v (up to 2.1 is save to set and forget, but I'm a bit more conservative, so raise more if needed to get your R15 scores up where they should be). That is to provide the needed power to the integrated voltage regulators in the chip (IVR). If out of balance (to low) when overclocking you wouldn't necessarily see instability but CB R15 would give you a lot lower Score (kind of throttling but kind of not since it's this time not heat related).
 
Start out with Vccio and System Agent Volt at stock (not Auto, figure out the stock values, XMP tends  to raise them unnessecarily high) start with 3200Mhz Ram speed, tweak Ram later. Those two Volts might need manual tweaking to run 4133 and would still be a fair bit lower than auto. 
 
If your cpu can't hold the 50x mulitplier in CB R15 and clocks down to lets say 47x then that would most likely be the -3 AVX offset in the bios. Hope EVGA offers seperate offsets for AVX and AVX 512. Try to find those and set them as desired. Just be warned they are there for a reason. AVX used by certain programs like Prime95 and R15 is very power hungry.
 
Then R15 is only very short load. You would usually not see VRM overheat on a short R15 run it takes usually a couple of minutes for them to saturate their little block. But they will definitely eventually overheat when using prime95. Might just put a fan on top. It's fine though during normal use.
 
The Mesh (formerly known as Cache might still be called like this in the bios) has a huge impact on this platform. It's worth raising it to 3000 since this should actually run at stock volts. sweetspot is 3200, that needs v1.1ish +/- 0.05v but Mesh hits a wall pretty soon after where volts won't help. So it's worth finding your sweetspot for mesh, since it also contributes to high temps.
 
Disclaimer: my experience is from the 7900X on an open testbench. I got my 7920X ready but EVGA can't make their mind up as to when to provide the X299 Micro in Germany.
The 7920X has a bigger die size which positively influences its ability to transfere heat between the die and the heatspreader due to a bigger surface area. But Mesh might need more volts, just work your way up. Nevertheless this chip is worth delidding, yours seems to be one of the better 25%.
 
Sry for typos, but I hope you get the idea, if you have any questions just ask.

EVGA board showed up today, the benchmark results are neck & neck with the MSI but the EVGA board is more stable and predictable. It's been stressing for the past hour and the 7920x looks good at 4.8, 1.269v. Had it up at 4.9 for a bit but the temps got into the low 100's so I pulled the plug. I should be able to get my little loop (200mm radiator, 2 Noctua 200mm fans push-pull) going by early next week though I'm not sure how much extra performance that's going to buy me. This EVGA 280 is pretty damn good.
 
Benchmarks
Cinebench R15             3121
Novabench                   3920 CPU 2327
CPU Z                          7749.6
Passmark CPU              22248

what the voltage on your cpu?

i have experience with all 2066 CPUs, about 2-4 chips of every model


100% of them does 4,7 at 1,25v
none of them is trotling and the mobo i use is cheap MSI x299 SLI PLUS
no other setting other that adjusting vcore was changed
 
in my experience this MSI is way better in preformance than RVIE - this might change as i didnt have any time for it

I sent the chip to Silicon Lottery for delidding it should be back for Friday, Saturday at the latest. I'm going to hook it back into the same system to see what was gained, I'm hoping for a stable 5.0 but 4.9 is probably more realistic, it'll be what it'll be. I've never delidded a chip before and may be expecting too much.
I'm off until Monday so I should have enough time to get the new case and watercooling set up rolling. I decided to add a 240 rad to the 200, it's the most I can fit in the case but it should equal a 5-120mm fan system for one CPU, best I can do. I'm really interested in the temp difference between the EVGA 280 and my coming little loop.

this weekend i will test my chip in RVIE, we will see what it can do
 
aslo 7920-80 - do not bother delid, makes no sense, u might gain 3'C and sometimes lose 5'C

The RAM I purchased for the MSI board isn't on the EVGA QVL list. I can run it at 4000 speed and only 3 sticks are recognized or I can run 4 sticks at 3600 and get less performance. Oddly there isn't a setting for 4133 in the bios, what's up with that? Obviously i can go out and buy the proper ram but is there any chance EVGA expands their QVL list as time goes on? I'd hate to buy a new set and then find out the current set is compatible.
 
The reason I ask is I was running benchmarks this morning and for a short time it was running 32gb at 4000 speed, I don't know how it happened but it did. Haven't been able to recreate it. My CPU-Z Benchmark went from 6800 to 8100, it was ridiculously good. If I can get this thing rolling at 4133 it should be that much better.

kinda do not agree
 
I had an ES too, 7900 after delid and LM i got an extra 15'C = worth it!!
7920X BOX after delid and LM i got +3/-5'C = not worth it!!
 
I delided so far 27 defferent s2066 CPUs, it is super easy comparing to previous gens
 
Next week I am selling one of my 7960X to a guy that believes he needs delid so I might share the numbers with you after he makes his final decision.

Just to wrap this up, over the weekend I reinstalled the MSI board and had very little luck with it. Highest stable overclock was a 4.7, not good. I'm not going to go around the internet blasting it but I wish I never bought it.
 
The EVGA board is holding up strong at 4.9 and is super solid. Thought I had it at 5.0 this morning, I could run a couple of benchmarks but gave up on it. Unless I install some better cooling it's 4.9 from here on in, to be honest I'm very happy where it's at.
Since I switched from override to adaptive I haven't seen a Cinebench score below 3200.
 
DDR4 is still an issue and it won't run the full complement, either 32GB at 3600 or 24GB at 4200, even though it's 4133 RAM. I've been running the 24 at 4200, the system likes it better. The plan is to sell all the extra stuff I bought (and my current ram) and go with the highest speed 64Gb set that the EVGA board will actually accept and then call it a day for 5 years with maybe some GPU upgrades now and then to keep things upwardly mobile.

I have a MSI X299, cheap one, and GSkill memory and it works fine...
Getting the same clocks as EVGA X299 Micro, same temps. etc...


Kinda irresponsible saying that what you have is bad and what you are expecting to buy is good...

I have experience with 11 motherboards total from Asus MSI Gigabyte and EVGA. All have issues...
 
X299 is simply rushed chipset and the market for HEDT is way smaller then for chips like Z and H. After X299 fiasco and launch of 6c chips for Z platform it will keep shrinking as most people do not need more cores only more performance pre cores that they already have. As a HEDT user with high core count I am also user of high performance drives. SATA I do not use at all. The main reason I am interested in EVGA is that FTW-K and Dark both have dual U.2. As these still are unavailable for purchase I bought Micro with onlu one U.2, and gues what. It doesn't work. On Asus and MSI it was also a challenge to get it to work but after some gimnastics and lots of time its working. With EVGA I am still waiting for it proper BIOS that will make this board compatible with Intels U.2 drive

I can say that for the OC difficulty and overall experience EVGA is OK, even better than others. But for performance and clocks that you can actually get are the same as others. But also EVGA has the same problems as competition and for the price you pay for this platform it is unacceptable. Not from EVGA and not from other brands...

Off course I would choose X299 Micro rather than any other mATX motherboard.
It's very interesting small motherboard with color scheme compatible with everything and nice for any mod.
She is perfect for i7-7820X or i9-7900X.