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[m4tr1x]

crossfire support on linux

hi,

i read about disable crossfire support for some issue unfixed.

http://code.google.com/p/pyrit/issues/detail?id=167

What's the problem with opencl/crossfire development?

With crossfire enable must be use master device when initializing opencl engine?

Thanks

[davibu]

Originally posted by: m4tr1x

What's the problem with opencl/crossfire development?

In my experience, crossfire must be always disabled before to run any OpenCL application. This is true not only for Linux but for Windows too.

[m4tr1x]

In my experience, crossfire must be always disabled before to run any OpenCL application. This is true not only for Linux but for Windows too.

Some moderator could explain why?

[empty_knapsack]

Because it's the way ATI do things.

... I'm way too angry to see that support for 5970 broken for 3 months already and for Windows there no easy way (or no way at all?) to disable crossfire for 5970.

[m4tr1x]

This way is documented somewhere?

[empty_knapsack]

It isn't documented because it's a bug, CAL/IL/OpenCL should work with crossfired GPUs. It just not fixed by ATI because <insert any reason here, like 3 months development cycle or anything else>.

[afo]

Hi,

To enable/disable crossfire in windows, you need at least two physical video boards. With this configuration the crossfire menu will be enabled in ccc and you will be able to disable it.

HTH

Alfonso

[m4tr1x]

Originally posted by: afo Hi,

To enable/disable crossfire in windows, you need at least two physical video boards. With this configuration the crossfire menu will be enabled in ccc and you will be able to disable it.

HTH

Alfonso

Windows ? No thanks

empty_knapsack : waiting for new sdk release ?

[empty_knapsack]

New SDK won't fix it, it's error at CAL layer ~= driver level. So it'll either be fixed with Catalyst 10.7 or it'll still broken. May be forever .

afo, of course there no problem to disable crossfire when two physical boards presents but for internal 5970's crossfire it isn't the case.

[davibu]

BTW, there has been a nasty bug introduced with driver 10.5 under Linux/Ubuntu 10.04, leading to Xserver crash in case of the presence of multiple GPUs. It is a known bug but it has not been fixed in driver 10.6.

There is a known workaround (consisting in deleting  /dev/vga_adapter  by hand) however it a bit disappointing to see how AMD/ATI seems to not care about a such HUGE bug (most people writting/using GPGPU software uses multiple GPUs).

[m4tr1x]

Originally posted by: davibu BTW, there has been a nasty bug introduced with driver 10.5 under Linux/Ubuntu 10.04, leading to Xserver crash in case of the presence of multiple GPUs. It is a known bug but it has not been fixed in driver 10.6.

I'm on ubuntu lucid (10.04), catalyst 10.6 and sdk 2.1, multiple gpu and no X crash.

Update all and reconfigure xorg

Originally posted by: davibu

There is a known workaround (consisting in deleting  /dev/vga_adapter  by hand) however it a bit disappointing to see how AMD/ATI seems to not care about a such HUGE bug (most people writting/using GPGPU software uses multiple GPUs).

What's your kernel version ?

With last kernel on lucid i not have your problem and /dev/vga_adapter is not present for me

[davibu]

Originally posted by: m4tr1xI'm on ubuntu lucid (10.04), catalyst 10.6 and sdk 2.1, multiple gpu and no X crash. Update all and reconfigure xorg

The bug is even listed in official 10.6 release notes and you can find the details here: http://ati.cchtml.com/show_bug.cgi?id=1828

[afo]

Hi,

The situation is worse than one ever think. HD5970 is shipping since november 2009 (so one could guess that prototypes were available internally for AMD since at least september 2009) but as today the official support in openCl for HD5970 is in single GPU mode only.

I am afraid of what kind of things are the developers doing that justifies the delayed support for this board for 6 months and counting.

frightened,

Afo.