3 ms·

I do light baking in Unreal Engine 4 using a program called 'Swarm' https://docs.unrealengine.com/en-US/Engine/Rendering/LightingAndShadows/Lightmass/UnrealSwar

by mentos 7y ago

I do light baking in Unreal Engine 4 using a program called 'Swarm' https://docs.unrealengine.com/en-US/Engine/Rendering/LightingAndShadows/Lightmass/UnrealSwarmOverview/index.html https://docs.unrealengine.com/en-US/Engine/Rendering/Lightin... Swarm only uses CPU power so you cannot take advantage of GPUs to bake lighting. I wonder if I could get 100 RPi4's to run Windows + Swarm and create a render farm for $3500...?

beckler 7y ago
Probably cost much more than that once you figure in the power and networking equipment. If I had the expertise, I would make large clusters with a bunch of the RPi CM3+.
- avian 7y ago
  Even with CM3+ I don't think the numbers add up. The 8GB CM3+ is $30, so after buying a hundred you're left with just additional $5 per board for power, interconnect and cooling (just like R.Pi 3, the compute module without additional cooling gets thermally throttled really quick). Since you can't run CM3 standalone, you'll be making custom hardware. Even if you don't count your development time, my gut feeling says that $5 is not enough to cover even just BOM costs for such a project.
cr0sh 7y ago
If I were doing this, there'd be a number of questions to ask yourself before you dumped a lot of money into it: 1. Is there a version of Windows for the RasPi (I think this is true, but it's been a while)? 2. Will Swarm and any other software you'd need for the cluster also run on the RasPi version of Windows? 3. How well does a single instance run on the RasPi? At that point, assuming #3 looks good - you could take it to the next level. Try two RasPi systems connected via a gigabit switch (cheap 5 port), and see how the performance scales vs a single instance. Then try four RasPi systems. At that point you should have enough data to determine how well a large render farm would run, compared to your desktop or whatever else you could come up with (would it be cheaper to spin up virtual servers as needed on AWS or similar?). Also realize that $3500 (approx) will only cover the RasPi systems; you'll need even more money for the power supply(s), cooling fans, switches, networking cables, power cabling, "enclosure" (even if just stacked using standoffs, you should still figure out how much all that will cost), etc. $4500 might be a more realistic figure. Even so - if it worked, and worked well - that dollar amount might not be that big a deal. Worst case, you could get a HN article out of it (whether as triumph or post-mortem - it would still be an interesting read).
robocat 7y ago
Bitscope is making a new edition of relatively cheap mounting hardware to make clusters of RPi 4 (current blade versions are compatible with RPi 4 but power supply limits kick in): https://bitscope.com/blog/JK/?p=JK34A https://bitscope.com/blog/JK/?p=JK34A For USD2850 you can get 3 rack mounts that can power 90 RPi 4's: http://my.bitscope.com/store/?p=view&i=item+7 http://my.bitscope.com/store/?p=view&i=item+7 The clusters can get pretty big: https://www.bitscope.com/blog/FM/?p=GF13L https://www.bitscope.com/blog/FM/?p=GF13L
imtringued 7y ago
Those clusters never made any economical sense. If you want to build a render farm then base it on a cheap 8 core chip like the Ryzen 2700 which retails for $200. Add $250 for a cheap motherboard, case, SSD, PSU, RAM. If your budget really was just $3500 then the Ryzen cluster would absolutely destroy the 100 core cluster but then there is also the fact that the $3500 only buy you bare SBCs. You still need a power supply, a case to mount 100 raspberry pis, a custom cooling solution, storage, a big switch or a huge amount of smaller switches. The total costs will be at least twice as high.

by mentos 7y ago

beckler 7y ago

Probably cost much more than that once you figure in the power and networking equipment. If I had the expertise, I would make large clusters with a bunch of the RPi CM3+.

avian 7y ago
Even with CM3+ I don't think the numbers add up. The 8GB CM3+ is $30, so after buying a hundred you're left with just additional $5 per board for power, interconnect and cooling (just like R.Pi 3, the compute module without additional cooling gets thermally throttled really quick). Since you can't run CM3 standalone, you'll be making custom hardware. Even if you don't count your development time, my gut feeling says that $5 is not enough to cover even just BOM costs for such a project.

cr0sh 7y ago

If I were doing this, there'd be a number of questions to ask yourself before you dumped a lot of money into it: 1. Is there a version of Windows for the RasPi (I think this is true, but it's been a while)? 2. Will Swarm and any other software you'd need for the cluster also run on the RasPi version of Windows? 3. How well does a single instance run on the RasPi? At that point, assuming #3 looks good - you could take it to the next level. Try two RasPi systems connected via a gigabit switch (cheap 5 port), and see how the performance scales vs a single instance. Then try four RasPi systems. At that point you should have enough data to determine how well a large render farm would run, compared to your desktop or whatever else you could come up with (would it be cheaper to spin up virtual servers as needed on AWS or similar?). Also realize that $3500 (approx) will only cover the RasPi systems; you'll need even more money for the power supply(s), cooling fans, switches, networking cables, power cabling, "enclosure" (even if just stacked using standoffs, you should still figure out how much all that will cost), etc. $4500 might be a more realistic figure. Even so - if it worked, and worked well - that dollar amount might not be that big a deal. Worst case, you could get a HN article out of it (whether as triumph or post-mortem - it would still be an interesting read).

robocat 7y ago

Bitscope is making a new edition of relatively cheap mounting hardware to make clusters of RPi 4 (current blade versions are compatible with RPi 4 but power supply limits kick in): https://bitscope.com/blog/JK/?p=JK34A https://bitscope.com/blog/JK/?p=JK34A For USD2850 you can get 3 rack mounts that can power 90 RPi 4's: http://my.bitscope.com/store/?p=view&i=item+7 http://my.bitscope.com/store/?p=view&i=item+7 The clusters can get pretty big: https://www.bitscope.com/blog/FM/?p=GF13L https://www.bitscope.com/blog/FM/?p=GF13L

imtringued 7y ago

Those clusters never made any economical sense. If you want to build a render farm then base it on a cheap 8 core chip like the Ryzen 2700 which retails for $200. Add $250 for a cheap motherboard, case, SSD, PSU, RAM. If your budget really was just $3500 then the Ryzen cluster would absolutely destroy the 100 core cluster but then there is also the fact that the $3500 only buy you bare SBCs. You still need a power supply, a case to mount 100 raspberry pis, a custom cooling solution, storage, a big switch or a huge amount of smaller switches. The total costs will be at least twice as high.