Utilisation of OpenGL GPGPU techniques?

NickK · Post by **NickK** » Thu Feb 19, 2009 2:40 pm

There's a technique used in GPGPU to perform the maths on GPUs rather than use the CPU - this called GPGPU. Rather than process each object seperately, parallel techniques are used to process all at maths for a set of object in parallel.

It's possible to use OpenGL todo this using a texture and a fragment, the final rendered and processed texture is then read as the result.

This is also supported as OpenCL under snow leopard in a better form but if you want to run big calculations on a large number of objects then GPGPU may be of interest to you.

Website · Post by **DaddyHoggy** » Thu Feb 19, 2009 3:00 pm

Welcome NickK!

come across GPGPU before - in fact I worked with a Polish student who showed me an application that he'd written that used the GPU of his 8800GTX to do some horribly complicated physics calculations four times faster than the PhysX card he had installed on the same PC. It was quite an eye-opener

(Of course now PhysX is incorporated into the latest nVidia cards anyway, but this was quite a few years ago).

JensAyton · Post by **JensAyton** » Mon Feb 23, 2009 10:33 am

No. This would take a lot of work, provide little benefit (not much of Oolite is maths-intensive), and would be of no use for our low-end users.

NickK · Post by **NickK** » Mon Feb 23, 2009 11:29 am

Ahruman wrote:
No. This would take a lot of work, provide little benefit (not much of Oolite is maths-intensive), and would be of no use for our low-end users.

True- however a decoupling and then increased support for intensity could allow a busier universe.. but it's true the game has a low horsepower requirement as it stands.

Screet · Post by **Screet** » Mon Feb 23, 2009 3:12 pm

NickK wrote:
Ahruman wrote:
No. This would take a lot of work, provide little benefit (not much of Oolite is maths-intensive), and would be of no use for our low-end users.
True- however a decoupling and then increased support for intensity could allow a busier universe.. but it's true the game has a low horsepower requirement as it stands.

According to the AMD/ATI forum, GPGPU support has been removed from ATI drivers. Not sure wether that's a bug or a feature, but users wrote that the new drivers explicitly remove that feature without replacing it by something similar.

I agree that the game does not require much horsepower. Sadly, the ATI 4870x2 Chipset performs quite bad, slowdowns to like 1fps. Not because the CPU or GPU would be busy - both are idle. Appears to be a driver issue using systems slow memory for rendering instead of the cards 2GiB DDR5. Reports about such speed problems have been reported by ATI users with many different cards and with many different OpenGL apps in the AMD/ATI forum, however, ATI does nothing about it. Asus plainly claims that the memory would be used and missing OpenGL acceleration claims would be baseless, yet they fail to explain why I experience such a slowdown and why the slowdown is reduced on machines with onboard memory faster than 1000 MHz.

Any good german lawyers around? I'm really fed up with advertised, but missing properties.

Screet