Why are blower cooling bad ?

Discussion in 'Video Cards' started by honegod, Aug 4, 2019.

  1. honegod

    honegod [H]ardness Supreme

    Messages:
    6,556
    Joined:
    Aug 31, 2000
    It seems to me that cooling a high powered card would work best by taking a suction on case internal air and expelling the heated air directly out of the case.

    Yet the concensus I see is that having 3 fans recirculating the heated air inside the case and using other fans to expell the heated case air is better.

    Why is this ?

    Is the blower fan woefully unable to move enough air through the heatsink,
    Or is the heatsink itself ineffectual at heating the air ?

    What is it ?
     
  2. ChadD

    ChadD 2[H]4U

    Messages:
    4,067
    Joined:
    Feb 8, 2016
    In general the smaller the fan the faster it needs to spin to move the same volume of air. This is why big massive CPU cooling towers have big massive fans. They don't need to spin as fast, to move a higher volume of air... so they tend to be quite.

    Bigger fan more air movement with less RPM = less noise. Also many blower housings tend to amplify the fan noise. (AMD claims that silly bend in their 5700xts reduces that)

    You are correct that the air needs to be vented. This is why AMD choose blower for their reference 5700s... and in the past NV has done the same. Non enthusiast PC folk can't be trusted to properly vent their cases. In general 2-3 fan vender boards get returned due to throttling and poor performance because of it... where as blowers tend to get returned as under load they can sometimes sound like jet engines.
     
  3. Archaea

    Archaea [H]ardForum Junkie

    Messages:
    9,262
    Joined:
    Oct 19, 2004
    It’s primarily about the noise.

    Expelling hot air outside the case is important of course, but case fans are generally reasonably silent these days and expel the heat without spinning up like a small hair dryer. The case fans do the job for the aftermarket double and triple fan cards.

    AMD blower cards are loud. There’s not much vent room on the back of the card with the 4-6 video card output connections and the blower fans spin up to high RPM without conscience. I had a rack of 12 1070 cards mining and just a single reference Vega 56 blower card under load was louder than all 12 triple fan PNY XLR8 1070 cards under load.
     
  4. chameleoneel

    chameleoneel 2[H]4U

    Messages:
    3,003
    Joined:
    Aug 15, 2005
    Blower style coolers often have smaller heatsinks and always have smaller fans
     
  5. matt167

    matt167 Gawd

    Messages:
    775
    Joined:
    Dec 18, 2016
    blower cards work very, very well. The problem is that squirrel cage blowers are very loud. They need to spin faster... On my spare T3500, I had 2 retired mining OEM Dell R9 270X cards crossfired. The fan on the top card had to be running over 70%-100% under load because of the very slight space between them. I just ran the same curve for both and it never got hot. But it sounded like it wanted to take off and fly across the room once those fans spooled up
     
    IdiotInCharge and Sulphademus like this.
  6. Archaea

    Archaea [H]ardForum Junkie

    Messages:
    9,262
    Joined:
    Oct 19, 2004
    AMD engineers are always seeking to get the most out of their reference card blowers. Here they are testing...

     
    DrezKill, nEo717, Bankie and 6 others like this.
  7. Dayaks

    Dayaks [H]ardness Supreme

    Messages:
    6,928
    Joined:
    Feb 22, 2012
    Like others said it basically comes down to surface area. I always wished someone would make a three slot blower. I’d buy that, but a two slot, given the exhaust area which is quite small you can only cool around 200W before things get loud. +/- 50W based on the quality of the blower.
     
    Armenius likes this.
  8. Tsumi

    Tsumi [H]ardForum Junkie

    Messages:
    13,007
    Joined:
    Mar 18, 2010
    Yep... would be nice if more motherboard manufacturers used the XL-ATX size and spacing for 3 slot blowers... alas multi-GPU is (mostly) dead, and the trend is towards smaller and more compact systems.
     
    Dayaks likes this.
  9. Snowdog

    Snowdog [H]ardForum Junkie

    Messages:
    8,979
    Joined:
    Apr 22, 2006
    Really we need some industry heavy hitters to get together and move beyond ATX standard. It was defined when you needed multiple cards in most PCs and none of them used much power. Today extra cards beyond GPU are more rare, and they now routinely use over 200 watts. It should be moved out of a card cage.

    Maybe have a CPU Cube that is much like an ITX board, in a small cube box, just large enough for 140mm intake and exhaust in a straight flow through line. This is much like what you get with CPU cooling today. It's a decent setup.

    Add two edge connectors on that cube.

    You can add a card cage on one edge connector if you need it, or you can a add a GPU cube, with the same kind of flow through cooling a CPU gets.
     
  10. ManofGod

    ManofGod [H]ardForum Junkie

    Messages:
    10,650
    Joined:
    Oct 4, 2007
    Their not bad, not even that R9 290 one, as long as you actually have the airflow needed to cool them off. The big issue with the R9 290 is they did produce a lot of heat and therefore, although they ran just fine with one reference card, using 2 of them together just produced more heat than most cases could handle. (I know, I tried that in an Fractal Design R3 case and one card, it was great but 2 cards, the case became very hot to the touch. (Not burning hot but you could definitely feel it.)

    Once again, proper airflow is the key.
     
    threehundredsixftw likes this.
  11. Tsumi

    Tsumi [H]ardForum Junkie

    Messages:
    13,007
    Joined:
    Mar 18, 2010
    That's an idea. Just use PCI-E risers integrated into the case or something like that.
     
  12. Dayaks

    Dayaks [H]ardness Supreme

    Messages:
    6,928
    Joined:
    Feb 22, 2012
    Oh crap - almost missed my chance to post my favorite video.

    Problem with blowers, especially on power hungry cards, is they are super loud/hot. As mentioned before the surface area on the exhaust just isn’t there. 290x ran at 95C and had failure rates above 10% IIRC.

     
  13. jeremyshaw

    jeremyshaw [H]ardForum Junkie

    Messages:
    12,055
    Joined:
    Aug 26, 2009
    To some extent, isn't that what Nvidia's mezzanine form factor for some GV100 and Tesla cards, and now that OAM form factor, is doing? Basically treating a small GPU-PCB like a socketed CPU. PCB is a something like MXM, but with all of the connectors on the bottom in pins/lands. The DGX-2 uses this form factor extensively.
     
    IdiotInCharge likes this.
  14. mnewxcv

    mnewxcv [H]ardness Supreme

    Messages:
    6,440
    Joined:
    Mar 4, 2007
    It was posted a few posts into this thread my man.
     
    DrezKill and Armenius like this.
  15. ManofGod

    ManofGod [H]ardForum Junkie

    Messages:
    10,650
    Joined:
    Oct 4, 2007

    Nah, in the Design R3 case I used to have, the reference cooler worked fine and it was not loud, since the case was designed with sound deadening material on it. Now, when I tried 2 cards at once, well, lets just say that was an experiment that did not last long at all.
     
    IdiotInCharge likes this.
  16. viivo

    viivo [H]ard|Gawd

    Messages:
    1,188
    Joined:
    Sep 7, 2005
    Blower designs are really bad for we OCD folks who can't comfortably game knowing temps are in the high 70s. With a blower there's no good compromise of noise and heat when you want max temperatures in the 50s, low noise, and maximum performance.
     
  17. N4CR

    N4CR 2[H]4U

    Messages:
    3,784
    Joined:
    Oct 17, 2011
    If you undervolt or set a custom fan curve they're fine.

    If you overclock, good luck. I only managed 40% oc on a 7970 ref.

    Tldr blowers suck because amd still offers them and no one cares about 720p raytracing. Hence blowers you're hearing about bcoz le amd suxx.
    Next launch hopefully they offer both reference founder Pioneer shareholder editions.
     
    Legendary Gamer likes this.
  18. honegod

    honegod [H]ardness Supreme

    Messages:
    6,556
    Joined:
    Aug 31, 2000
    So since the shape of the overall package is dictated by the ATX standard the fan must be tiny, and the limited exaust area requires high pressure, the tiny impeller must spin really fast which makes it really loud.

    Since my case positions the MB flat the card fan is pointed at the side panel, where I could put a Noctua 12-25 ducted directly into the card intake.
    Which would increase the air pressure, I am thinking increase significantly.

    Now I am thinking about how to increase the exaust area without using up all 4 expansion slots (matx case), there is a likely looking area above the slots that's not being used for anything so far.

    Thoughts ?
     
    threehundredsixftw and Gamer X like this.
  19. jeremyshaw

    jeremyshaw [H]ardForum Junkie

    Messages:
    12,055
    Joined:
    Aug 26, 2009
    I feel that is not strictly the case, since Nvidia (and probably AMD) have released cards that exceed the ATX physical specs, even all the way back to the 8800 Ultra (at least).
    https://www.geforce.com/hardware/desktop-gpus/geforce-8800-ultra/product-images

    Now, it's not a particularly effective breach of ATX form factor, but partner AIBs have definitely taken the lead on that.

    Since I seriously doubt there are many fullsize (even OEM) cases that really require an extremely strict adherence to ATX height spec, there should be a reasonable extension of the height for blower cards. That being said, I know a large (or not insignificant) portion of the blower market is for 3U rackmount servers, where that vertical height is somewhat tight.

    Even so, the power pigtail is often oriented incorrectly for such a setup, so this exists:

    https://www.servethehome.com/asrock-rack-3u8g-c612-8-way-gpu-server-review/

    Either way, I hope (if reasonably beneficial), we can get some more interesting blower cards in the future.


    Either that, or mezzanine/OAM style cards, like the GV100 mezzanine.
     
    Armenius and IdiotInCharge like this.
  20. Snowdog

    Snowdog [H]ardForum Junkie

    Messages:
    8,979
    Joined:
    Apr 22, 2006
    Until it is actually some kind of official form factor, there won't be good cooling solutions for it.

    With the Power they are consuming, GPU's should have cooling solutions comparable to CPU solutions.

    People have hacked CPU coolers on GPUs:
    GPU_Cooler.jpg

    But then it's a hack, and you probably can't make it fit in the case. Ideally you a new high performance gaming form factor would have a the GPU in it's own area, just like the CPU with a nice exhaust fan because getting rid of heat is a huge part of the issue, a blower has the right philosophy, just the wrong execution. You need a nice upright 120mm fan cooling that GPU and another one exhausting heat.
     
    jfreund likes this.
  21. Gamer X

    Gamer X Limp Gawd

    Messages:
    270
    Joined:
    Jul 5, 2019

    The Concept of blowers is not a bad one, it is the limited space and noise of fan speed on a Video card.. that is the hinderance. Matter of fact, a blower design is superior for your over-all system, because it directly moves heat out of your case. Again, there is nothing wrong with a blower design and if you wanted you could spin those fans up like a blower drying and cool your GPU.... but the noise!

    If they started making triple-slot blowers, with more than one fan.. it would be a win/win.
     
    Armenius and KATEKATEKATE like this.
  22. ManofGod

    ManofGod [H]ardForum Junkie

    Messages:
    10,650
    Joined:
    Oct 4, 2007
    Not so much with the R9 290 Blower fans though. It worked fine with one but when 2 were combined, the heat would completely overwhelm whatever system they were installed in.
     
    IdiotInCharge and Gamer X like this.
  23. Gamer X

    Gamer X Limp Gawd

    Messages:
    270
    Joined:
    Jul 5, 2019
    I am talking in concept and theory. There has not been a proper "blower" design GPU card made yet.
    Years ago, you could buy Blower cards... that sat directly above, or below you GPU.. that help suck radiant heat out of your case, thus away from the system. Deltas & ambients were much better.

    Understand, both designs cool the GPU, but only one style (blower), removes that heat from the case. While Axial Fan Video Cards are great for localized heat dissipation & OC, they just spin that hot air around the case.



    The win/win comes from having two blower fans in a triple-slot design, because you have equal thermals and lower sound. But that becomes expensive to make.

    As such, It is much cheaper for AIBs just to make two axial fans blowing down on heatpipe & fins, than to design a unique blower solution. Mostly because AIO water cooling is too damn cheap (relatively speaking) and solves all 3 problems. GPU water blocks for something like NAVI are going to be ultra-common in just 2 years time.


    ed:
    In the winter, I know people who use double water pumps chilling long runs of tubing through the snow... to Fold/Mine. Not to mention a massive bump in FPS...
     
    Last edited: Aug 5, 2019
  24. purple_monster

    purple_monster Limp Gawd

    Messages:
    455
    Joined:
    Jun 1, 2018
    Why are blower cooling bad ?
     
    DrezKill, Armenius and GoldenTiger like this.
  25. honegod

    honegod [H]ardness Supreme

    Messages:
    6,556
    Joined:
    Aug 31, 2000
    Got YOUR attention, Aye. ;)
     
  26. doubletake

    doubletake Gawd

    Messages:
    540
    Joined:
    Apr 27, 2013
    Armenius and IdiotInCharge like this.
  27. cjcox

    cjcox [H]ard|Gawd

    Messages:
    1,180
    Joined:
    Jun 7, 2004
    The 'big boys" (and others) design some really compact units that don't really have reasonable other ways to help with cooling, and assume a "blower" style. To put a non-blower card in some of those units (which might not fit even) would result in overheat.

    It's just a thing. So, depending, a blower card might be your only sane choice.

    DIY folks usually have bigger cases with air flow that allows for the non-blower type boards.
     
  28. honegod

    honegod [H]ardness Supreme

    Messages:
    6,556
    Joined:
    Aug 31, 2000
    How would the two impellers be mounted ?

    I can see how triple slot thickness would allow the impeller to be taller for more air volume, and allow the fins to be taller both allowing lower pressure, AND allowing more fin surface.
    Also allowing the exaust area to be larger, reducing pressure requirement.

    But how would the second impeller work ?
     
    Armenius and Snowdog like this.
  29. Furious_Styles

    Furious_Styles [H]ard|Gawd

    Messages:
    1,330
    Joined:
    Jan 16, 2013
    IS it though?
     
    GoldenTiger likes this.
  30. honegod

    honegod [H]ardness Supreme

    Messages:
    6,556
    Joined:
    Aug 31, 2000
    Triple recirculaters seem to be all the rage amongst the non water cooling community, not blowers.

    So if not where are the AFTERMARKET blower conversion kits to replace the clearly inferior triple fan setups ?
     
  31. Snowdog

    Snowdog [H]ardForum Junkie

    Messages:
    8,979
    Joined:
    Apr 22, 2006
  32. Unknown-One

    Unknown-One [H]ardForum Junkie

    Messages:
    8,869
    Joined:
    Mar 5, 2005
    I'd like to see MicroATX and ITX boards where there's a right-angle PCIe 16x lot along the bottom edge of the board, so that graphics cards end up mounted parallel to the motherboard.

    This would allow for the use of air coolers similar what we we currently see on CPUs, and should still fit in standard ATX cases (even legacy ones, if the graphics cards are designed with outputs that align to the existing expansion slots)
     
    threehundredsixftw likes this.
  33. M76

    M76 [H]ardForum Junkie

    Messages:
    9,195
    Joined:
    Jun 12, 2012
    Blower type fans have very little surface area where they move the air, so they are unable to move that much air no matter how fast they spin. Of course there are situations where it is more important where the hot air is directed at, than how much air is moved. that's why blowers didn't go the way of the dodo yet, because they work even in badly ventilated cases. That's why reference designs are usually the blower type imo. Because they are not affected by case airflow that much.

    So to sum it up:
    If you have a very small case with bad air circulation a blower is better. In every other scenario regular fans move more air therefore provide better cooling while being significantly less noisy.
     
    Armenius likes this.
  34. Comixbooks

    Comixbooks Ignore Me

    Messages:
    13,202
    Joined:
    Jun 7, 2008
    Noise with the more powerful fans but Nvidia's stock cooler have improved this gen I think. They are good for tight build though were cooling is at a premium in tight spaces.
     
  35. Furious_Styles

    Furious_Styles [H]ard|Gawd

    Messages:
    1,330
    Joined:
    Jan 16, 2013
    Whoosh. hehe :)
     
    GoldenTiger likes this.
  36. purple_monster

    purple_monster Limp Gawd

    Messages:
    455
    Joined:
    Jun 1, 2018
    this is a really bad thread. op won and i know he is slowly reaching inside his sweatpants as he reads all of these comments.

    blower type fans are far superior. in fact my favorite thing to do is put my face right behind the exhaust during a stress test and smell that warm dusty/ozone/electrical smelly smell smell that smells.

     
  37. honegod

    honegod [H]ardness Supreme

    Messages:
    6,556
    Joined:
    Aug 31, 2000
    Do blower cards use heat pipe tech, or just big slabs of aluminium ?

    I thought about heat pipes but I (currently) don't see how to run them.

    I really dislike the heat pipe setup of the
    HIS HD 7870 IceQ Turbo
    .
    imagine then

    Wtf is going on with the font ? Retry.
     
  38. honegod

    honegod [H]ardness Supreme

    Messages:
    6,556
    Joined:
    Aug 31, 2000
    Do blower cards use heat pipe tech, or just big slabs of aluminium ?

    I thought about heat pipes but I (currently) don't see how to run them.

    I really dislike the heat pipe setup of the HIS HD 7870 IceQ Turbo.

    Imagine your hand waving at someone, fingers spread out.
    Like the heat pipes of that big Noctua twin tower. The airflow hits all the pipes at the same time, Like if you blew at your fingers, but if you turn your hand like you are thumbing your nose at the person standing next to the person you waved at and blow at your fingers now your index finger gets ALL the fresh, cool air , your pinky will only see air that has been preheated by all the other fingers.
     
  39. Tsumi

    Tsumi [H]ardForum Junkie

    Messages:
    13,007
    Joined:
    Mar 18, 2010
    Blower type coolers generally do not use heatpipe-based heatsinks; they typically use vapor chambers. Both operate on the same principle, but vapor chambers are more efficient at transporting heat to a physically close heatsink, as is the case with blower coolers.

    Also, the orientation of the heatpipes do not matter. The heatpipes don't do the heat transfer to air, the fins of the heatsink do. Well technically yes they would contribute, the amount of heat dissipated by heatpipe-air transfer is negligible compared to fin-air.
     
  40. honegod

    honegod [H]ardness Supreme

    Messages:
    6,556
    Joined:
    Aug 31, 2000
    I was going for a visual.
    As the air flows along the line of pipes, the part of the fins associated with each pipe are sequentially seeing hotter air and so will not cool the pinky pipe as well as the first pipe which sees cooler air running along it's fin stack area.

    So, I don't like designs that thumb their nose at me, I want each pipe to have the maximum cooling, not just the first one.