Scientific Visualization and GFX cards

[Minotaar]

Hi All,

Long time gamer, long time scientist.

My scientific code has taken many twists and turns over the years, but a consistent aspect of my work includes rendering surfaces with a huge number of triangles. These aren't fancy textured, shaded, etc triangles. It's just a loose bag of triangles.

Such triangles draw badly for a number of reasons; if you really want to push geometry, you need to do triangle strips and fans and other things in order to save memory bandwidth to the card. I've coded openGL for ages, and I know this, but I'm in a situation where I don't have control of the code. I only have control of the hardware.

So here's my question - what video card can I get that will push gajillions of simple triangles fast as hell without framerate drops, given my limited PCIE bus bandwidth? I fully realize that the answer might be "nothing - you are limited by the PCIE bus, and your performance plateaus for all modern gfx cards, sorry". I've explored a lot of midrange gaming cards (e.g. gtx x65 stuff; never tried anything high end though) but I was wondering if I would get more out of a higher level gtx or a titan? As I understand it, sli makes no difference because that's mostly about fill power and doing lots and lots of passes, and less about geometry, but please correct me if I'm wrong.

 

[thecoolnessrune]

If your requirements are extremely high, and all you are doing is computations, have you considered renting space on one of the smaller supercomputers? Especially if this is more for a one-time thing

 

[MathMan]

Do the triangles fit into GPU memory? In OpenGL, you can give hints to an object buffer about how the data is used. With the right hints, the driver may place the triangles in GPU memory and you won't be limited by PCIe bandwidth.

Of course, if your application sends triangles to the GPU in the old fashioned way:

glBegin
glVertex
glVertex
glVertex
glEnd

... then you're probably going to be out of luck.

Still a Quadro driver may be smarter about packing openGL data before sending it to the GPU than a GeForce driver. It's probably worth a try? Maybe you could start with a low cost Quadro card and see how it performs compared to a GeForce card with the same silicon. If the Quadro card is way faster than the GeForce, a beefier Quadro will probably faster as well.

 

[Minotaar]

Yup, thats exactly how I'm sending triangles.

I thought the quadro was the same as the gtx etc, except iwth different driver support? I'll have to look into it.

Brian

Do the triangles fit into GPU memory? In OpenGL, you can give hints to an object buffer about how the data is used. With the right hints, the driver may place the triangles in GPU memory and you won't be limited by PCIe bandwidth.

Of course, if your application sends triangles to the GPU in the old fashioned way:

glBegin
glVertex
glVertex
glVertex
glEnd

... then you're probably going to be out of luck.

Still a Quadro driver may be smarter about packing openGL data before sending it to the GPU than a GeForce driver. It's probably worth a try? Maybe you could start with a low cost Quadro card and see how it performs compared to a GeForce card with the same silicon. If the Quadro card is way faster than the GeForce, a beefier Quadro will probably faster as well.

 

[NTMBK]

The OpenGL drivers for Quadro are massively better than the ones for Geforce.

 

[Minotaar]

The OpenGL drivers for Quadro are massively better than the ones for Geforce.

The Geforce market is more competitive. It's basically the same hardware. Why would they give up driver performance on the consumer level?

 

[mv2devnull]

Basically.

There was a time, when a hacked Geforce driver believed that a Geforce card was a Quadro card, and enabled Quadro-only stereo mode. That was short-lived; Nvidia soon made sure in hardware that simple software hacks could not undermine their market segmentation.

There are still features, such as quad-buffered OpenGL stereo, that are enabled with Quadro, but not with Geforce. It makes no sense, but it probably makes money.

Why would a consumer use OpenGL? "All" games use DirectX, and Microsoft has been "expectedly" biased on what it supports.
Why would professionals use DirectX? "All" pro applications use OpenGL.
The segmentation is rather strong, despite the apparently non-existent differences.

 

[Minotaar]

Thanks for the insights, all.