Double precision performance of consumer graphics card

Discussion created by kugeleck on May 15, 2011
Latest reply on May 15, 2011 by kugeleck
OpenCL with a 64bit real-time Linux kernel


NVIDIA limits the double precision performance of their consumer graphics cards to 25% of the possible performance. The GeForce GTX 550 Ti has 691.2 GFLOPs [1] and therefore would be capable of 345.6G double precision floating point operations per second. It is limited to 86.4G though. So for Fermi-based consumer cards the double precision performance is 1/8 of the single precision performance.

Does AMD also limit the double precision performance?

According to what I red double precision performance is 1/5 of single precision performance with AMD GPUs. This means that the Radeon HD 5850 has a double precision performance of 417.6G which is 20% of 2088 GFLOPs [2] .

I want to use OpenCL with a 64bit Linux real-time kernel. The NVIDIA driver supports this but as far as I know the AMD one does not? Is real-time support planned? I found information online on how to use the AMD driver in a real-time environment. That requires quite a few code changes though. Then again with the AMD card I would get almost a 400% performance increase.

Taking all of the above into account would it be better to buy a Radeon HD 5850 for OpenCL programming since it costs the same and also supports OpenCL1.1?

[1] http://en.wikipedia.org/wiki/GeForce_500_Series#GeForce_500_Series

[2] http://en.wikipedia.org/wiki/Comparison_of_ATI_graphics_processing_units#PCIe_.28HD_5xxx.29