I like the picture of the 100+ SPARCstation render farm for the first Toy Story
https://mobile.twitter.com/benedictevans/status/766822192197...
Pixar's Render Farm
21–30 of 323 posts
Re: Pixar's Render Farm
#22My understanding (I am not an authority) is that for a long time, it has taken Pixar roughly an equal amount of time to render one frame of film. Something on the order of 24 hours. I don’t know what the real units are though (core-hours? machine-hours? simple wall clock?) I am not surprised that they “make the film fit the box”, because managing compute expenditures is such a big deal! (Edit: When I say "simple wall…
Well it can't just be one frame total every 24 hours, because an hour-long film would take 200+ years to render ;)
They almost certainly render two frames at a time. Thus bringing the render time down to only 100+ years per film.
Re: Pixar's Render Farm
#23It's good to know they care about optimization. I had the assumption that all CGI is a rather wasteful practice where you just throw more hardware at the problem.
In the end it’s still more profitable to hire performance engineers than hardware. For the last decade I’ve heard the “toss more HW” argument. It hasn’t held because the amount of compute and storage goes up too.
In reality it’s never as simple as a single soundbite. If you are a startup with $1k/mo AWS bills, throwing more hardware at the problem can be orders of magnitude cheaper. If you are running resource-intensive workloads then at some point efficiency work becomes ROI-positive.
The reason the rule of thumb is to throw more hardware at the problem is that most (good) engineers bias towards wanting to make things performant, in my experience often beyond the point where it’s ROI positive. But of course you should not take that rule of thumb as a universal law, rather it’s another reminder of a cognitive bias to keep an eye on.
Re: Pixar's Render Farm
#24Earlier quoted context omitted.
I’m going to guess they have more than one computer rendering frames at the same time.
Yeah, I was just (semi-facetiously) pointing out the obvious that it can't be simple wall-clock time
Why can’t it be simple wall-clock time? Each frame takes 24 hours of real wall-clock time to render start to finish. But they render multiple frames at the same time. Doing so does not change the wall-clock time of each frame.
Re: Pixar's Render Farm
#25My understanding (I am not an authority) is that for a long time, it has taken Pixar roughly an equal amount of time to render one frame of film. Something on the order of 24 hours. I don’t know what the real units are though (core-hours? machine-hours? simple wall clock?) I am not surprised that they “make the film fit the box”, because managing compute expenditures is such a big deal! (Edit: When I say "simple wall…
Well it can't just be one frame total every 24 hours, because an hour-long film would take 200+ years to render ;)
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Re: Pixar's Render Farm
#26Earlier quoted context omitted.
In the end it’s still more profitable to hire performance engineers than hardware. For the last decade I’ve heard the “toss more HW” argument. It hasn’t held because the amount of compute and storage goes up too.
That’s very much an exaggeration. Pixar/Google etc can’t run on a single desktop CPU and spends a lot of money on hardware. The best estimate I have seen is it’s scale dependent. At small budgets your generally spending most of that on people, but as the budget increase the ratio tends to shift to ever more hardware.
It is absolutely about scale.... an employee costs $x of dollars regardless of how many servers they are managing, and might improve performance y%..... that only becomes worth it if y% of your hardware costs is greater than the $x for the employee.
Re: Pixar's Render Farm
#27Earlier quoted context omitted.
I’m going to guess they have more than one computer rendering frames at the same time.
Yeah, I was just (semi-facetiously) pointing out the obvious that it can't be simple wall-clock time
It could still be wallclock per-frame, but you can render each frame independently.
Re: Pixar's Render Farm
#28My understanding (I am not an authority) is that for a long time, it has taken Pixar roughly an equal amount of time to render one frame of film. Something on the order of 24 hours. I don’t know what the real units are though (core-hours? machine-hours? simple wall clock?) I am not surprised that they “make the film fit the box”, because managing compute expenditures is such a big deal! (Edit: When I say "simple wall…
Wait, what? 24 hours per frame?! At the standard 24fps it takes you 24 days per film second which works out to 473 years for the average 2 hour long film which can't be right.
It's definitely not 24 hours per frame outside of gargantuan shots, at least by wall time. If you're going by core time, then it assumes you're serial which is never the case.
That also doesn't include rendering multiple shots at once. It's all about parallelism.
Finally, those frame counts for a film only assume final render. There's a whole slew of work in progress renders too, so a given shot may be rendered 10-20 times. Often they'll render every other frame to spot check and render at lower resolutions to get it back quick.
Re: Pixar's Render Farm
#29Earlier quoted context omitted.
Yeah, I was just (semi-facetiously) pointing out the obvious that it can't be simple wall-clock time
Why can’t it be simple wall-clock time? Each frame takes 24 hours of real wall-clock time to render start to finish. But they render multiple frames at the same time. Doing so does not change the wall-clock time of each frame.
In my (hobbyist) experience, path-tracing and rendering in general are enormously parallelizable. So if you can render X frames in parallel such that they all finish in 24 hours, that's roughly equivalent to saying you can render one of those frames in 24h/X.
Of course I'm sure things like I/O and art-team-workflow hugely complicate the story at this scale, but I still doubt there's a meaningful concept of "wall-clock time for one frame" that doesn't change with the number of available cores.
Re: Pixar's Render Farm
#30It's good to know they care about optimization. I had the assumption that all CGI is a rather wasteful practice where you just throw more hardware at the problem.
CGI is heavily about optimization. I recommend checking out SIGGRAPH ACM papers , and there's a great collection by them on production renderers.
Every second spent rendering or processing, is time an artist is not working on a shot. Any savings in optimizations add up to incredible cost savings.