TUF x570 m.2 placement choices

[fillasophy]

I'm waiting on the parts for my new rig to arrive (https://pcpartpicker.com/list/q37q27), so thinking over the build.  While the system is compatible with 4.0, I went with a 3.0 nvme ssd, which I believe should work in either of the board's two m.2 slots, top (m.2_1) and bottom (m.2_2).  Now, I'm new to m.2, but I've heard that the m.2_1 slot connects to the CPU, while the m.2_2 slot routes through the x570 chipset.  I just have no idea what this means or implies...lol.  I was hoping that 1) someone could help me understand what the concepts of lanes is, how each routing path impacts this, and what this looks for my system, and 2) get thoughts on which m.2 slot to use.  I would note that the m.2_2 slot has a heatsink, so in terms of cleaning up the system visually that would be my preference, but is there an advantage to performance or stability by using one slot over the other in my setup (including when considering the heatsink, which looks to only work with m.2_2)?

 

Thanks!

[NewMaxx]

That is correct - using M.2_1 is better but it's not really a huge difference. M.2_2 has to go over the chipset so adds a small amount of latency. I've personally noticed issues with certain drives over the X570 chipset, specifically SM2262/EN-based drives like the SX8200 Pro. Unfortunately AMD and SMI (controller manufacturer) never got back to me on that issue. That problem also is largely unnoticeable in usage, both of these things you will only see on synthetic benchmarks.

[fillasophy]

Thank you for the reply!  (PS - nice reddit...so much info!) 

58 minutes ago, NewMaxx said:

using M.2_1 is better but it's not really a huge difference

Based on what you're saying about the small (albeit likely unnoticeable) performance benefit of the m.2_1 slot, and from what I've seen about nvme drives generally wanting to run on the warm side, I'll go with m.2_1.  So, now to the follow-up question...

 

The drive comes with a small plastic piece with a 3M adhesive backing what looks to be for affixing to the SSD, I would assume for tidying up the appearance like I'm aiming for (see pics).  If/since I'm using m.2_1, I'm inclined to use it, but will it potentially cause thermal issues to the point it might start throttling the ssd or melt the adhesive?  I'm using a tower cpu cooler, so there's a decent chance the ssd will be visually obstructed and this is moot, but in case I do use it I wanna know what I'm getting myself into.

 

Thanks again!

[NewMaxx]

It's a heatspreader. It doesn't do much so, yes, mostly about aesthetics. You can run without it and decide to install it later if you want.