The 970 is on the back slot on the underside of the mobo. I beleive temp 2 is the controller. First is just with a Twitch stream playing, the second is closing it and letting it idle. I went ahead and ordered 2 S12A fans, hopefully can collect tomorrow.
Your 970 controller seems to run a little hot during drive activity but at idle seems fine. Here's what my two m.2 drives look like on my NZXT H1:
The GPU in this case lives in its own bay and I have a wimpy RX 550 2GB card that isn't pumping tons of heat onto the auxiliary m.2 (which also lives on the backside of the motherboard) unlike your RDNA2 card.
I am using the same 970 EVO Plus and the drive and controller temps are just one degree Celsius apart. The m.2 slots on the backside of these B550 mini-ITX cases are just open slots. What sort of heatsink do you have on the 970?
If I recall correctly, this is a single-sided SSD (no chips on the bottom) so I used two thermal pads on the bottom tray of the heatsink. If you don't, there's not enough pressure to push the drive's chips onto the thermal pad on the heatsink's top assembly.
The same principle is in effect on the primary m.2 (Gen4) slot on the front side of your motherboard. Is your Samsung 980 PRO a single-sided or dual-sided SSD? If it is single-sided (no chips on the bottom), then you need to put a small rubber spacer on the support post under the middle of the drive. Read your motherboard's owners manual carefully and look at the accessories it shipped with. Normal this spacer is just a small black square 0.5 cm on each size, something that could easily get overlooked. Again, the extra thickness (maybe a millimeter) is enough to push the SSD's chips on top into the thermal pad of the motherboard's first heatsink.
The Samsung's drive do run a bit on the hot side so you should be more motivated to provide extra case ventilation. There isn't anything completely out of whack though. They seem to be functioning within their normal operating ranges.
My 970 EVO Plus replaced an ADATA XPG 8200 which ran about ten degrees cooler. The Sabrent Rockets run much cooler than the Samsungs.
Remember that I am not using my Asus motherboard's heatsink for the Sabrent; I am using Sabrent's add-on heatsink.
Of course, it's still the winter here in the Northern Hemisphere and I would expect the drive temperatures to be about 3 degrees higher on a normal summer day. This NZXT H1 build is not a gaming PC, it's really my daily driver productivity system (hence the ghetto Lexa-based GPU).
Without a doubt PC cooling technology has greatly improved in the past 20-25 years. Designing a good cooling system requires
far more thought and analysis than selecting a motherboard or case if you care about acoustics. If you wear headphones 24x7 then go with the cheap noisy RGB blinged-out fans.
