4 ms·

I've always wondered why motherboards aren't placed at a slight angle like the wing of a car so that the air moving over it has a higher angle of incidence, hig

I've always wondered why motherboards aren't placed at a slight angle like the wing of a car so that the air moving over it has a higher angle of incidence, higher pressure, and higher thermal capacity. With the angle, you can also place cable connectors and whatnot on the bottom of the board so they don't obstruct airflow as much. Basically, optimize PV = nRT inside the computer case at no extra cost other than a redesign.

SketchySeaBeast 4y ago
I would assume because the things with the greatest heat have typically had such a requirement for active cooling that minor optimization wouldn't have helped much and for everything else you really didn't worry about (though my motherboard now has heat-pipes across the VRMs and my RAM and northbridge have got big old heat spreaders).
- CoolGuySteve 4y ago
  Yeah, the way my case is laid out, airflow to the VRM is blocked by the heat spreaders on the RAM and the ATX power connector. AMD systems in particular seem to require better memory thermals. It seems like we're reaching a point where a new ATX standard is required to ensure the memory and GPU can make contact with a large heatsink similar to how the trashcan Mac Pro and XBox Series X are designed. Doing so would also cut down on the ridiculous number of fans an overclocked gaming PC needs these days, my GPU and CPU heatsinks have 5 80mm fans mounted to them. ATX is great but it seems like only minor improvements to power connectors and whatnot have been made since it was introduced in 1995.
  - Macha 4y ago
    Are the trashcan Mac Pro and Xbox Series X considered effecient cooling solutions? I thought the trashcan Pro had issues at higher temperatures which in turn limited their ability to use higher end parts and in turn forced the return of the cheese grater? The series X GPU then is considered equivalent to a desktop 3070, and laptop 3080s exist and are also considered equivalent to a desktop 3070, so don't require anything particularly novel in terms of cooling solutions (3080 laptops are loud under load, but so is the series X). Overclocked components are so heavy in cooling needs as they're being run so far outside their most efficient window to get the maximum performance - which is why datacenters which care more about energy usage than gamers tend to use lower clocked parts.
    - CoolGuySteve 4y ago
      Both systems are a fraction of the size of an ATX case and as efficient as they needed to be to meet their predetermined convective cooling needs. In both cases, profit margin is increased by reducing material and shipping volume requirements. A similar single heatsink design for high end PCs would need to be much larger than either of those designs but considering how much empty space is in an ATX case, I don't think it would be much larger than current PCs. Consider that the best PC cooling solutions all look like this: https://assets1.ignimgs.com/2018/01/18/cpucooler-1280-1496174542219-1516305067126.jpg https://assets1.ignimgs.com/2018/01/18/cpucooler-1280-149617... Or pass liquid through a radiator with comparable volume, standardizing the contact points for a single block heatsink with larger fans would make computers more efficient and quiet.
picture 4y ago
It won't be a simple redesign to tilt boards "slightly" because manufacturing processes that are already honed in need to be completely retooled, with likely more complexity (man different length of standoffs per board?) And additionally, there are only a few key components of a motherboard that need cooling. Most of the passive components like the many many decoupling capacitors don't generate significant heat. The components that do require access to cool air are already fitted with finned heat sinks and even additional fans. They interact with air enough to where a slight tilt cannot make a meaningful difference. Basically just adding a small piece of aluminum to key areas will work better than angling the whole board
saltcured 4y ago
I'm struggling slightly to envision the effect you are seeking. My motherboards don't tend to be flying through the air and so lack a well-defined angle of attack... :-) There already exist horizontal and vertical motherboard mounts in different computer cases, including ones that could be stood either way to suit the desktop. In my experience, this doesn't affect cooling that much. I think the fan, internal baffle, and vent positions dominate the airflow conditions inside the case. So, rather than tilting a motherboard, wouldn't you get whatever you are after with just a slight change in these surrounding structures?
- CoolGuySteve 4y ago
  You seem to be ignoring that all the punch through connectors on a board are currently on the side that air must pass over. Furthermore, I've never seen a case, either desktop or rackmount, that allows one to angle the fans at anything other than a 90 degree angle or parallel to the board. None of this makes sense in terms of fluid dynamics.
  - saltcured 4y ago
    Having a smooth board seems at odds with having a large surface area for heat transfer, doesn't it? And wouldn't laminar flow also have less movement near the surface? For optimal cooling, would you actually want turbulence to mix the layers? Instead of mounting fans at different angles, add some vanes or even duct work to aim and accelerate the flow where it needs to transfer heat. But, given that boards do not have completely standardized layouts, it seems like you eventually need to assume a forest of independent heat sinks sticking up in the air. You lose the commodity market if everything has to be tailor made, like the integrated heat sink and heat pipe systems in laptops.
kllrnohj 4y ago
You don't really need to pass any air over the PCB, though. Anything that needs cooling sticks up above it. Also the airflow through a case isn't perfectly parallel to the motherboard PCB anyway. GPU fans throw the air in all sorts of directions, including straight down into the motherboard. And so do CPU coolers. Cables also don't really obstruct the airflow like at all.
dtgriscom 4y ago
Car wings are angled because you're stuck with the direction the wind goes relative to the car (assuming you're driving with all wheels on a surface). Inside a computer, designers have a lot of freedom in where they direct the air flow. So, they plan the layout with space efficiency in mind, taking into account the needs of cooling.

SketchySeaBeast 4y ago

I would assume because the things with the greatest heat have typically had such a requirement for active cooling that minor optimization wouldn't have helped much and for everything else you really didn't worry about (though my motherboard now has heat-pipes across the VRMs and my RAM and northbridge have got big old heat spreaders).

CoolGuySteve 4y ago
Yeah, the way my case is laid out, airflow to the VRM is blocked by the heat spreaders on the RAM and the ATX power connector. AMD systems in particular seem to require better memory thermals. It seems like we're reaching a point where a new ATX standard is required to ensure the memory and GPU can make contact with a large heatsink similar to how the trashcan Mac Pro and XBox Series X are designed. Doing so would also cut down on the ridiculous number of fans an overclocked gaming PC needs these days, my GPU and CPU heatsinks have 5 80mm fans mounted to them. ATX is great but it seems like only minor improvements to power connectors and whatnot have been made since it was introduced in 1995.
- Macha 4y ago
  Are the trashcan Mac Pro and Xbox Series X considered effecient cooling solutions? I thought the trashcan Pro had issues at higher temperatures which in turn limited their ability to use higher end parts and in turn forced the return of the cheese grater? The series X GPU then is considered equivalent to a desktop 3070, and laptop 3080s exist and are also considered equivalent to a desktop 3070, so don't require anything particularly novel in terms of cooling solutions (3080 laptops are loud under load, but so is the series X). Overclocked components are so heavy in cooling needs as they're being run so far outside their most efficient window to get the maximum performance - which is why datacenters which care more about energy usage than gamers tend to use lower clocked parts.
  - CoolGuySteve 4y ago
    Both systems are a fraction of the size of an ATX case and as efficient as they needed to be to meet their predetermined convective cooling needs. In both cases, profit margin is increased by reducing material and shipping volume requirements. A similar single heatsink design for high end PCs would need to be much larger than either of those designs but considering how much empty space is in an ATX case, I don't think it would be much larger than current PCs. Consider that the best PC cooling solutions all look like this: https://assets1.ignimgs.com/2018/01/18/cpucooler-1280-1496174542219-1516305067126.jpg https://assets1.ignimgs.com/2018/01/18/cpucooler-1280-149617... Or pass liquid through a radiator with comparable volume, standardizing the contact points for a single block heatsink with larger fans would make computers more efficient and quiet.

picture 4y ago

It won't be a simple redesign to tilt boards "slightly" because manufacturing processes that are already honed in need to be completely retooled, with likely more complexity (man different length of standoffs per board?) And additionally, there are only a few key components of a motherboard that need cooling. Most of the passive components like the many many decoupling capacitors don't generate significant heat. The components that do require access to cool air are already fitted with finned heat sinks and even additional fans. They interact with air enough to where a slight tilt cannot make a meaningful difference. Basically just adding a small piece of aluminum to key areas will work better than angling the whole board

saltcured 4y ago

I'm struggling slightly to envision the effect you are seeking. My motherboards don't tend to be flying through the air and so lack a well-defined angle of attack... :-) There already exist horizontal and vertical motherboard mounts in different computer cases, including ones that could be stood either way to suit the desktop. In my experience, this doesn't affect cooling that much. I think the fan, internal baffle, and vent positions dominate the airflow conditions inside the case. So, rather than tilting a motherboard, wouldn't you get whatever you are after with just a slight change in these surrounding structures?

CoolGuySteve 4y ago
You seem to be ignoring that all the punch through connectors on a board are currently on the side that air must pass over. Furthermore, I've never seen a case, either desktop or rackmount, that allows one to angle the fans at anything other than a 90 degree angle or parallel to the board. None of this makes sense in terms of fluid dynamics.
- saltcured 4y ago
  Having a smooth board seems at odds with having a large surface area for heat transfer, doesn't it? And wouldn't laminar flow also have less movement near the surface? For optimal cooling, would you actually want turbulence to mix the layers? Instead of mounting fans at different angles, add some vanes or even duct work to aim and accelerate the flow where it needs to transfer heat. But, given that boards do not have completely standardized layouts, it seems like you eventually need to assume a forest of independent heat sinks sticking up in the air. You lose the commodity market if everything has to be tailor made, like the integrated heat sink and heat pipe systems in laptops.

kllrnohj 4y ago

You don't really need to pass any air over the PCB, though. Anything that needs cooling sticks up above it. Also the airflow through a case isn't perfectly parallel to the motherboard PCB anyway. GPU fans throw the air in all sorts of directions, including straight down into the motherboard. And so do CPU coolers. Cables also don't really obstruct the airflow like at all.

dtgriscom 4y ago

Car wings are angled because you're stuck with the direction the wind goes relative to the car (assuming you're driving with all wheels on a surface). Inside a computer, designers have a lot of freedom in where they direct the air flow. So, they plan the layout with space efficiency in mind, taking into account the needs of cooling.