Powerful graphic card for MacPro 2010

zanroversi's picture

Hello,

For the needs of a show : "Meduse" with Vincent Glowinski, I run a QC-Cocoa application on a good MacPro (10.7 - 2010).

An effect in this software displays several images (with a iterator and "add-blended" sprites) from an large image queue which stores the 400 last images from the HD camera. A sort of video-delay.

You can have a look here : http://vimeo.com/81827116 (the process I talk about starts around 1:40). (see also attached demo).

Performances and more annoying : stability, are getting bad if I try to iterate more than 16 pictures. The VRAM is full, fps is falling down, and the whole app can crash at any time...

Could anybody give me an advice to be more comfortable with that ? I suppose, a bigger graphic card should be a good idea, but I can't figure what model should be good.

Thanks by advance for your enlightenments, any help will be greatly appreciated !

Best.

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gtoledo3's picture
Re: Powerful graphic card for MacPro 2010

There's an example of this in the developer compositions supplied by apple when you go to their site and read up on QC, or look at the old developer install. I can't remember the name of the composition though.

The concept is basically that the images get resized as they are loaded, and then I think they're all put into a queue.

Basically, people tend to hold gigantic images in memory instead of converting them to the size that they'll take up on screen.

I believe also, that passing them through a "render in image" patch, shifts where the images live to "vram", which is also done in the composition I speak of.

zanroversi's picture
Re: Powerful graphic card for MacPro 2010

Hello, thank you,

Resizing down images before storing them in the queue was my first idea to speed-up. But, beyond the loss of image quality, it didn't worked, neither for fps improvement nor crashes.

By monitoring VRAM with OpenGL Driver Monitor, I saw that images are stored into VRAM even if no render in image is in use. I tried also the opposite : force storing images in RAM (with a custom plugin I made on this purpose, in order to improve stability rather than FPS). But I reached the limits of my skills.

I checked in the old examples provided by Apple, and didn't found something I consider to be similar. Maybe Video-feedback.qtz, I'll study that.

The better thing I can do today is decrease the qty of images under 300. The software is far more stable, i can display 16 images simultaneously. But I need to have more delay between two displayed images, and dream of a 600 images queue, even if I only display 16 sprites... That's why I thought about a new graphic card. Is it a bad reasoning ?

Greetings.

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Alexander Mitchell's picture
Re: Powerful graphic card for MacPro 2010

I agree 100% with gtoledo3.

My GPU is a AMD 7970, and this works 100% with the newest quartz. (and also all OpenCL apps!)

When you are running a live show, its a matter of optimising and overkill with hardware as far as I am concerned. Even with a backup system its best to use the most extreme hardware at the time.

Just my 2 cents.

Cheers, Alex