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0 pointsdoctorpangloss9y ago0 comments

> stupid way of doing it

I guess it really depends on what the objective is. I'm not talking speculatively, but concretely it seems like a reasonable way to achieve a few images that they show in the press release. They show two relatively flatly rendered lots-of-tubes images. I know SSAO isn't the same, and I get that there's overdraw, but there are a lot of details in the particular objective they want. In one shot, they show a lot of emissive tubes with depth of field, which is harder to achieve. I suppose if they're happy, they're happy.

> interactive performance for all datasets on a regular Intel Xeon processor, which can render images at 20-25 frames per second (FPS)

There's a big difference between interactive performance and a production-quality render. Something tells me it's not producing 25 frames of noise-free render per second. There isn't enough information here.

> and a dual Xeon can match a single top-of-the-line GPU

At what, like 3x-5x the price? At how many watts? And at what I.T. complexity? A GTX 1080, at better performance than a Titan X, is really a phenomenally good deal. Especially considering I can drop it into an existing workstation with all of my existing software installed on it; especially considering I can rent out computation time on Amazon by the hour.

I guess what I'm reacting to is how forced of an example it seems.

0 comments

berkut9y ago

I think the objective is rendering a ridiculous amount of stuff - the fact they talk about "lots and lots of RAM" indicates there's no way a GPU is going to be able to render it efficiently without an aggressive culling step: GDDR5 might be very fast, but you've got to get the data onto the GPU first and probably page data as well. This is very often a significant bottleneck for GPUs, and is another reason GPUs aren't used for VFX rendering (at high-end), as 16 GB isn't anywhere near enough.

Production-quality render implies decent lighting and materials - this stuff has neither, so shading is likely to be negligible, and then you're going to be generally constrained by ray / primitive intersection performance.

No, cheaper (for CPU) : two ~$950 CPU cores vs $3,300 GPU. Granted you need a dual-socket system and twice the RAM to balance and it's easier to stick multiple GPUs in a system than make the jump to 4 sockets, but GPUs aren't really that much of a win... Thermal output and power usage is often worse for GPUs as well.

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