SG-2440 temp lowered from 46°C to 39°C



  • Greetings!

    Fwiw, this SG-2440 runs dual-WAN, Snort, pfBlockerNG, and IPsec VPN with aplomb.

    I was a little uncomfortable with the reported temperature of 46°C (115°F) tho..

    Check-out my redneck hyperbolic chimney; it lowers the temp to 39°C (102°F)

    Patent pending; to get one today; send $49.95 to … ~grins~


  • Galactic Empire

    Nice! You might have better results if you take the SG-2440 off your switch ;)



  • @ivor:

    Nice! You might have better results if you take the SG-2440 off your switch ;)

    Thanks! But, if so; not much. I've also got pfSense running on a old AMD motherboard open-case PC with a cpu-fan and that runs between 38°C and 39°C. I was pleasantly surprised how much draft I got from this.

    YMMV



  • Try to add small fan on cpu.
    No need to be high speed.
    On my SG-4860 1U with small fan on cpu i have 29~31 C.


  • Netgate Administrator

    "Do NOT remove!"  ;D


  • Banned

    Does it work with KFC's gear? I hate McD… :P



  • @stephenw10:

    "Do NOT remove!"  ;D

    I need to write that higher on the cups too. "Hey, look; someone left their soft drink back there.."

    Before I had the hyperbolic chimney idea, I just wanted to ensure that the grille wasn't covered



  • @doktornotor:

    Does it work with KFC's gear? I hate McD… :P

    KFC? Sure! There may be a better height & shape too. Warm-up the 3-D printer.. :-)



  • Below 50c is plenty fine. SSDs are most sensitive to heat and have a typical max of 50c-60c. CPUs can go much higher. Modern Intel server CPUs don't start to throttle until 110c and shutdown at 120c. I had a GPU that was 103c-108c when gaming and I gamed about 6-10 hours a day. Did that for 6 years before replacing it. I gave it to my brother where he used it for another year before upgrading.

    Cool is better, but below boiling is fine. Except storage, they really don't want to be hot.



  • I didn't want to put a fan on top and chance it failing and blocking the air flow so I got a small 12 volt squirrel cage blower and set it up blowing into the side vents. I'm powering it off a handy USB port on a nearby computer so it runs slow and quiet at 5 volts. If it dies there will be no airflow impact.

    It is happily running at 34C in a 27C room.

    I first tried an 18" chimney setup using some poster board that worked at cooling but failed the spousal approval test.



  • Can somebody explain how that decreases the temperature by such a large margin? I'm looking up hyperbolic chimneys and I'm even more confused because of the way OP set it up



  • I submerge mine in ice water…



  • @Soarin:

    Can somebody explain how that decreases the temperature by such a large margin? I'm looking up hyperbolic chimneys and I'm even more confused because of the way OP set it up

    Physics my friend
    heatsink warms air, this air being lighter is going up to chimney, it creates underpressure in casing, so cold air is sucked.

    In theory longer chimney , this effect will be stronger.
    https://en.wikipedia.org/wiki/Stack_effect



  • @ivor:

    You might have better results if you take the SG-2440 off your switch ;)

    All my desktop gear sits atop these which significantly lowers temperatures. It's also convenient for cable routing. :)

    If you look closely, you can see them in my closet pic here.



  • @Soarin:

    Can somebody explain how that decreases the temperature by such a large margin? I'm looking up hyperbolic chimneys and I'm even more confused because of the way OP set it up

    OP here. Technically, it's just the stack-effect updraft, as nicely documented by NineX. And, taller is better to a point..

    Stan-Gaz made an 18-inch straight chimney using poster board, but didn't say how well that worked. Since my chimney is only 14-inches, I expect he drafted a little better.

    The base diameter is driven by the vent. Diameters above that can be reduced to save material when that's needed, to a point.. The Hyperbolic shape uses the least material between the three desired dimension points; base, waist-line, and outlet.

    http://hvac-talk.com/vbb/showthread.php?135780-What-is-a-good-rule-of-thumb-regarding-duct-velocity says that duct velocity can go up to 600 FPS without turbulence. So, an arbitrary 1.5 inch diameter waist-line should pass up to 7.4 CFM, and I think our convective updraft is well below that.

    Nuclear cooling facilities widen their tops so that the water-vapor does not shoot into the sky like a geyser does. Stack outlet velocity is actually regulated in places too.

    My soda-cup version has a 4.25-inch inlet, 2.9-inch waist-line, and 3.8-inch outlet. There's obviously no benefit of enlarging our dimension above the waist-line here. But those soda-cups were really handy..

    My next version will be a simple 24-inch conical tee-pee made from poster-board; 4.25 inches at the base, with a 1.5 inch opening at the top.  I'll post again when I get around to making that. (it might be a while tho.. ;-)



  • I'm amazed at how people are resistant to add a heat sink sufficient to get things cool because it would mean having a larger case, but they are OK with stacking cups, which is bigger.  I mean if you have it and don't want to change it, ok.  But if you are building or buying, why not just make sure it has great cooling to begin with?  That thing is taking up more space than my mini-itx case.  Sorta defeats the purpose of buying tiny cases right?



  • @kejianshi:

    I'm amazed at how people are resistant to add a heat sink sufficient to get things cool because it would mean having a larger case, but they are OK with stacking cups, which is bigger.  I mean if you have it and don't want to change it, ok.  But if you are building or buying, why not just make sure it has great cooling to begin with?  That thing is taking up more space than my mini-itx case.  Sorta defeats the purpose of buying tiny cases right?

    Talk to Netgate. I taped the first cup over the vent so that it couldn't be accidentally covered. The second cup, and this hyperbolic chimney thread, has been just for fun.  The factory-original 46°C cpu-temp was not that alarming.  I'm just an obsessive/compulsive Engineer with a lot of soda-cups laying around.

    Personally, I'm always amazed how some people will spend gobs of money and tons of time on technical overkill. E.g. a water-cooled Raspberry Pi  https://www.youtube.com/watch?v=RggpIEYh9VU

    Granted tho, I'm overkill here myself, on the cheap, with soda-cups out of the trash-can and poster-board. Would you recommend doing water-cooling instead?  ~grins~


  • Netgate Administrator

    It doesn't need that chimney, sure. But that's kinda missing the point.  ;)

    It gets my vote.  ;D

    Steve



  • haha - OK.  Now I understand how this came to be.  An accident with benifits.


Log in to reply