overheating on Plex transcoding

[calgarychris]

Hi,

Just wondering if there's something wrong with my system or whether I'm asking too much of it. I currently run FreeNAS on a Supermicro X10SLM+- with Xeon E3-1231 with 32GB of RAM (and Raidz2). I have 3 jails and a VM (4GB of RAM and 4 virtual CPUs). The VM runs folding@home and the 3 jails are Nextcloud, Plex and one that has Sabnzbd, Radarr and Sonarr. This is a home setup so nothing is getting smashed in terms of users or capacity.

When I try to transcode with Plex, my temperature spikes within 10-15 seconds to 95-99C and I get critical warnings (so I shut it down). I've tried stopping the folding project, which I know is CPU intense but it doesn't seem to make a difference. I've taken the machine apart, cleaned all filters and fans and installed another exhaust fan (which did help bring the temps down slightly). For context, running the jails and the folding project puts CPU usage at 14-20% and temps at around 70-85C (lower now that it's got another fan).

Am I asking too much of this processor? I would have thought running one Plex transcode would be easily done as the machine barely breaks a sweat doing anything else. I've only got the Intel CPU cooler on it and to be honest the thermal paste is probably toast given the age, would replacing that make a substantial difference? Any suggestions?

Thanks

 

[Yorick]

Replacing thermal paste is a good idea, and if that doesn't do it, you need a bigger cooler. You're not asking too much of the CPU: You are just not cooling it adequately.

For what it's worth, I am running a newer-gen Xeon with just the stock cooler. The older ones did run hotter though, so if refreshing thermal paste doesn't do the trick, go for an aftermarket cooler.

 

[spiceygas]

When I try to transcode with Plex, my temperature spikes within 10-15 seconds to 95-99C and I get critical warnings (so I shut it down).

Replacing thermal paste is a good idea, and if that doesn't do it, you need a bigger cooler.

From many years of desktop PC experience, I would agree with Yorick that thermal paste is a likely culprit. A spike that fast usually means that heat is not being transferred from the IHS to the cooler.

It's possible that the cooler is undersized, though that usually doesn't spike so quickly.

Either way, thermal paste is a quick step with good odds of fixing your problem. There are tons of Youtube videos about application if you've never done it before.

 

[calgarychris]

Thanks guys, I was afraid you'd say that! Haha, I did the original thermal paste 5-6 years ago, but I'll refresh my knowledge courtesy of Youtube and reapply (once I buy the cleaner and new paste). Hopefully that does the trick, I guess otherwise it's a better cooler (I'm just using the stock one). Any recommendations for coolers - Noctua?

 

[spiceygas]

Thanks guys, I was afraid you'd say that! Haha, I did the original thermal paste 5-6 years ago, but I'll refresh my knowledge courtesy of Youtube and reapply (once I buy the cleaner and new paste). Hopefully that does the trick, I guess otherwise it's a better cooler (I'm just using the stock one). Any recommendations for coolers - Noctua?

Lookup the TDP for your CPU (80W according to Intel Ark) and ensure that the cooler can handle it. Depending on your case, make sure that it'll fit.

Noctua is a good brand. There are other good brands, too. If you buy a high-quality, brand name cooler and a good thermal paste then you'll be in good shape.

 

[pschatz100]

I would agree that temperature spiking within 10-15 seconds indicates your CPU cooler isn't doing anything. Thermal paste is a likely culprit. Even if the CPU fan wasn't running, it would take longer than that to overheat.

By the way, thermal paste does not last forever. On old machines, it is good practice to replace the thermal paste every few years - so if you've been running for 5 or 6 years then you have had a good run and it is time for some maintenance.

 

[calgarychris]

Thanks guys, the advice is much appreciated. I've got Noctua NT-H1 paste on its way, along with some Arctic Silver ArcticClean. Hopefully that sorts out the CPU cooling issue without having to go down the upgraded cooler path.

Woke up to another issue, one of my drives is kicking out "ata status: 41 (DRDY ERR), error: 40(UNC). It's been kicking out sector errors for years but this one's new and looks like it's about to die. At least I saved on shipping by getting the HDD at the same time right? lol

 

[calgarychris]

By way of follow-up - I just wanted to say thanks very much for the advice guys. I can report that having applied the paste, I tested today running 3x concurrent transcoding streams plus running Folding@Home in a VM with visualisation and the temperature never breached 70C. I can't believe what a difference it makes, but then, I know nothing of thermodynamics. Thanks for the advice!

 

[spiceygas]

By way of follow-up - I just wanted to say thanks very much for the advice guys. I can report that having applied the paste, I tested today running 3x concurrent transcoding streams plus running Folding@Home in a VM with visualisation and the temperature never breached 70C. I can't believe what a difference it makes, but then, I know nothing of thermodynamics. Thanks for the advice!

I'm glad to hear that it's improved.

Some googling indicates that the max temp for your CPU is 73C. If you're nearing 70C then you're close to the maximum. Keep an eye on it.

If you want to further lower your temps then you may have to look at a new cooler. That's a bit more of an investment than thermal paste.

 

[calgarychris]

I'm glad to hear that it's improved.

Some googling indicates that the max temp for your CPU is 73C. If you're nearing 70C then you're close to the maximum. Keep an eye on it.

If you want to further lower your temps then you may have to look at a new cooler. That's a bit more of an investment than thermal paste.

Ah, yes I see that now...Might have to look at a stock cooler as, even after three tries I couldn't get the fourth pin to lock down. I was just happy it was below 80C which it has been running at for months. I've probably shortened the life a bit, but it's been running 24/7 for five years now.

Thanks for the tip - any suggestion on coolers? I've been seeing that Noctua air coolers are pretty good...

 

[spiceygas]

I couldn't get the fourth pin to lock down.

What do you mean? if you are saying that the four corners of the heat sink are not secured correctly to the motherboard then that's a really bad thing.

Thanks for the tip - any suggestion on coolers? I've been seeing that Noctua air coolers are pretty good...

Noctua is a good brand. They are especially well known for their fan quality and low noise. There are other good brands, too. You'll need to do a little research and read reviews, but in general if you stick to a highly rated brand then you'll be in good shape.

Another thing to think about is noise. If the computer is somewhere that noise doesn't matter (e.g. in the basement) then a fan that moves more air (at the cost of more noise) might be an option. It's not exactly this simple, but generally more air == more heat transfer == lower temps.

 

[Constantin]

... I did the original thermal paste 5-6 years ago, but I'll ... reapply (once I buy the cleaner and new paste).

Use as little paste as possible. Compared to the CPU die or the cooler, the thermal resistance of the paste is huge. Both of those surfaces should have been lapped at the factory, so the amount of available "dead space" assuming proper alignment should be minimal. That's why they should be as shiny as a mirror - that's what a lapped surface looks like.

Hopefully that does the trick, I guess otherwise it's a better cooler (I'm just using the stock one). Any recommendations for coolers - Noctua?

I'd check into what reputable review sites recommend for your particular motherboard / CPU. Otherwise, go stock and see if that fixes the problem. Stock may mean a louder fan - i.e. small cooler die combined with a high-flow fan. The engineers at Supermicro evidently expected my motherboard to be fitted inside a trans-sonic windtunnel at NASA.

Ah, yes I see that now...Might have to look at a stock cooler as, even after three tries I couldn't get the fourth pin to lock down.

Danger Will Robinson! If the CPU die and the cooler HX surface are not aligned properly, then you cannot expect the cooler to function properly. At best, you may be getting a good contact for part of the die while other parts are still thick with paste. If the pins don't fit, get a better-fitting cooler - see my comment above - i.e. find something that someone has tested with your particular motherboard / CPU holder.

 

[calgarychris]

Yeah, unfortunately after three tries (cleaning the paste off each time) there is one pin that consistently doesn't lock in (or at least, I don't hear it). I apply even pressure across the two diametrically opposed pins but it just doesn't seem to want to go (works for the other two). I've used as much force as I feel comfortable doing as I don't want to crack the board. I've also tried swapping the holes that pin goes into but it doesn't make a difference unfortunately.

I've cleaned the die and cooler with Arctic Clean - probably could've stuck with isopropyl but now I've got a lifetime supply of CPU thermal paste cleaner, so there is that (lol). I watched videos on how much paste to apply and followed Noctua's guidelines for small dies, so I'm reasonably happy I didn't overdo it (and besides, I had three tries!). I'll keep the stock cooler on for now and see about potentially getting something else - it means a more complete disassembly though as I can't get to the back of the motherboard to put any back plates on without completely dismantling the machine.

With aftermarket coolers - some are bloody huge - is there an issue with it in a tower case with it mounted? It seems like a big chunky cooler hanging off the side of a motherboard would put some stress on it, no?

Cheers

 

[spiceygas]

You should be worried if the cooler is not screwed down correctly on all corners. That's just tempting fate.

The aftermarket coolers that are oversized usually correlate with better heat dissipation. It's not exactly 1:1, but in general, bigger (from a good brand) means cooler temps. You're right, though, that they can get pretty big. Depending on size and shape you need to think about:

• Overall height (is it too tall?)
• Airflow obstruction (depending on fan orientation, if the fan is next to a wall in your case then it'll choke)
• Hitting your RAM, especially if you have RAM with tall heat spreaders
• Hitting VRMs heatsinks (rare, but some motherboards have big heatsinks that can get in the way)

Most products have at least the total height listed, so get out a measuring tape and check that before you buy it.

 

[pschatz100]

Glad to hear that replacing the thermal past helped. But keep in mind that, if all four pins are not secure then the cooler will not be seated properly.

I run a stock cooler on my FreeNAS, but on another machine that used for video encoding, I use a Coolermaster Hyper 212 Evo. It was reasonably priced, straightforward to install, and works well. Just double-check all your clearances as it is a rather tall unit.

 

[ornias]

Glad to hear that replacing the thermal past helped. But keep in mind that, if all four pins are not secure then the cooler will not be seated properly.

I run a stock cooler on my FreeNAS, but on another machine that used for video encoding, I use a Coolermaster Hyper 212 Evo. It was reasonably priced, straightforward to install, and works well. Just double-check all your clearances as it is a rather tall unit.

I'm really sad they made the U12S only a few mm's too big to fit a 4U case :'(