Question Move OS to the cooler slot?

gn842a

Honorable
Oct 10, 2016
666
47
11,140
I have two M.2 NVMe's installed on my Asus Prime X470 Pro. One has the OS and any programs I download. The other holds data. I have additional things going on for data backup, but we can focus my question down to the specific issue: the OS is on the M.2 which is closest to the CPU and tends to run about ten to fifteen degrees warmer. But when I run some benchmarks it hasn't exceeded 60C which isn't so bad.

The other M.2 is on real estate that is a few more inches away and on the other side of the GPU. It tends to run around 35c.

So my question is

  1. Is it a mistake to have the OS M.2 in the hotter spot nearest to the CPU
  2. If I move it is it going to remain the C drive and the other one remain the D drive

As I see the question of whether to swap the two M.2s' positions revolves around two issues. Which is more of a hassle to replace if it fails, the OS drive or the data drive?

--To this question I answer it would be easier to replace the data drive. I have other backups both in and outside the box so the aggro factor of an NVMe crashing if all it has is data is minimal.
--That said, life has gotten much easier since I adopted the system of keeping only the OS and programs, no data at all, on the OS drive. I "know the drill" on reinstalling everything.

But what I would really like to know is whether the M.2 closest to the cpu is really a "one should worry" thing or a "get on with your life, it will be fine" kind of thing. This is very new technology (for me anyhow) and I'm a little leery of it.

There is the additional fact that in my limited experience the failure mode is always something you haven't thought of.

thanks,
Greg N
 
You could do that but it will run at SATA speed because second M.2 port is not PCIe x4 but PCIe x2.
I have Samsung 960 evo and it tends to run warm but never overheats. Without that integrated heat sink(on my Asus Prime x370 pro) it was hitting 90c under benchmarks. It's actually their controller chip that gets hot, not memory chips themselves so there's no danger of loosing data.
 
  • Like
Reactions: gn842a

gn842a

Honorable
Oct 10, 2016
666
47
11,140
You could do that but it will run at SATA speed because second M.2 port is not PCIe x4 but PCIe x2.
I have Samsung 960 evo and it tends to run warm but never overheats. Without that integrated heat sink(on my Asus Prime x370 pro) it was hitting 90c under benchmarks. It's actually their controller chip that gets hot, not memory chips themselves so there's no danger of loosing data.

This is a good point. Somewhere I actually knew the second slot would run SATA--it was pointed out to me in another thread about how to interpret some bench marks--but I didn't connect the thought to the desirability of running the OS on PCIe x 4 and keeping it that way.

I guess part of the reason for that is that my previous build had OS on a SATA drive in a bay and it is so much faster than HDD that there is very little room for noticeable improvement (in use, not bench mark) over that. But yeah M.2 boots up fast.

I did some additional benchmark tests and the M.2 temp never got higher than the mid 50s, but the second slot always ran about ten degrees cooler. So it's all working to within spec.

The CPU also runs cool, gets into the 40s during these tests, the autobalance on the fans has yet to crank up to maximum. I think that in fact, the issue is that the heat from the GPU rises towards the PCIe x4 slot, and that is the source of the heat, not the CPU. During the bench mark tests the GPU temp hit 70 - 71 degrees. This is right at the threshold where autobalance is supposed to put the gpu fans at 100%, but it never happened.

Anyhow the hottest component in the system is the GPU and maybe the best thing for the M.2 above it would be to try to get the GPU fans to push to 100% earlier than they currently are.

thanks, Greg N
 

gn842a

Honorable
Oct 10, 2016
666
47
11,140
I say don't worry about it.

OTOH the Modder in me wants to look into the possibility of placing some kind of shield between CPU and M.2 so hot air not blowing directly onto it. But that's just me.

I think that would be hard to pull off, leastaways for me. I'm sure if I did it I would set something on fire. :) A shield would at a minimum change the air flow and perhaps not in a way that would benefit the overall situation.

thx
Greg N
 

prophet51

Reputable
Jun 14, 2019
171
28
4,640
You could do that but it will run at SATA speed because second M.2 port is not PCIe x4 but PCIe x2.
I have Samsung 960 evo and it tends to run warm but never overheats. Without that integrated heat sink(on my Asus Prime x370 pro) it was hitting 90c under benchmarks. It's actually their controller chip that gets hot, not memory chips themselves so there's no danger of loosing data.

NVME can run at 2x even 1x speed. 1X is still almost 50% faster that sata3.
 
  • Like
Reactions: gn842a

gn842a

Honorable
Oct 10, 2016
666
47
11,140
We actually have benchmark data on this thread from my build which shows the second M.2 running more slowly, as was interpreted by USAFret.

When I put this thread up I had forgotten a speed penalty would be involved in making the move. I think I'm going to stick with their current positions.

It is true that even at half speed the M.2 is still very fast, but if I get really worried about heat I should move the OS to a SATA drive in a bay. There would be a speed penalty for that too, but it would be in a thermally very different part of real estate. Even the PCIe 2 slot for M.2, which is further from the cpu, is still between the psu and the gpu, so probably not as cool a spot as out in one of the bays.

But for now they all stay put I think. This build is almost complete, still waiting for RMA'd gpu replacement.

Greg N