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[reggyj]

Hi, there. I need help getting double precision working in my openCL application on the GPU.

Double precision works fine on the CPU, but when I try to run it on the GPU it fails.

My Graphics Cards is  ATI Radeon HD5850 which is as far as I can tell, should work http://en.wikipedia.org/wiki/Comparison_of_AMD_graphics_processing_units#Evergreen_.28HD_5xxx.29_ser...

It tells me it can't enable cl_khr_fp64 or cl_amd_fp64, but since my graphics card should be able to run 64bit, I'm at loss for why.

I'm using the 13_1 drivers for my graphics card, and I have version 2.8 of the SDK.

Specs:

Windows 7 64 bit

ATI Radeon HD5850

Visual Studio 2010 Professional

13_1 mobility Graphics drivers.

AMD APP SDK 2.8

Thanks in advance, any help is appreciated.

[nou]

Do you have desktop GPU. Because AFAIK there is no mobility radeon GPU which support DP.

[reggyj]

I am working from a laptop. Does that mean, I'm screwed? I thought the graphics card would be what's important.

[Bdot · Accepted solution]

The mobility numbers are higher than what is actually in it. If you search the page you linked for "Mobility Radeon HD 5850" you'll see that it is actually a "Juniper", which in desktop terms is the 57xx series that does not offer DP.

Some of the newer mobility devices (HD77xxM - HD79xxM) are based on GCN and should support DP.

[reggyj]

Well, that's confusing and dumb.

Thanks for your help.

[himanshu_gautam]

Try running "clinfo". This will list the support extensions as well as other device specific information.

Therein , you can check if cl_khr_fp64 (or) cl_amd_fp64 is enabled for your device.

btw.. You should be able to find this programatically as well.