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[ThomasUCF]

four GPU installed correctly,only one working

   Hi all, I installed two HD 5970s in my computer, that is equal to four HD5870s. When I run the Nbody simulation in the ATI stream sample, only one is working. How can I make them work together? 

   Thanks a lot!

[himanshu_gautam]

ThomasUCF,

In SDK version 2.2 only a few samples run on all available GPUs including SimpleMultiDevice,MandelBrot. All other samples run by default on the 0th device. 

In version 2.3 you will have the option of choosing the gpu(on which you want to run the sample) in multigpu systems.

I hope the doubt is cleared.

[ThomasUCF]

 Thank you so much, it's a great help.

 Here I have another, when I change all device[0] in the sample code  to device[1], it's not working right. Do you have any ideas?

[himanshu_gautam]

ThomasUCF,

Send a test case.

[ThomasUCF]

 Hi Himanshu:

For example, the Nbody problem, when I change device[0] in the sample code to device[1], I can nolonger see all the particles moving, I can only see one particle in the center.

 Any explanations on this?

 Thanks a lot.

Thomas

[nou]

this may be bug related to that second core of 5970 return garbage results. do you have windows? on linux there are posibility that 5970 working correctly.

[himanshu_gautam]

Please post the output of SimpleMultiDevice sample.

[ThomasUCF]

----------------------------------------------------------
CPU + GPU Test 1 : Single context Single Thread
----------------------------------------------------------
Total time : 59.0422
Time of CPU : 54.4086
Time of GPU : 5.24897
----------------------------------------------------------
CPU + GPU Test 2 : Multiple context Single Thread
----------------------------------------------------------
Total time : 59.0422
Time of CPU : 56.7377
Time of GPU : 2.00775
----------------------------------------------------------
CPU + GPU Test 3 : Multiple context Multiple Thread
----------------------------------------------------------
Total time : 59.7269
Time of CPU : 59.2351
Time of GPU : 2.00951
----------------------------------------------------------
Multi GPU Test 1 : Single context Single Thread
----------------------------------------------------------
Total time : 41.9174
Time of GPU0 : 4.61716
Time of GPU1 : 3.12945
Time of GPU2 : 3.16599
Time of GPU3 : 2.01411
----------------------------------------------------------
Multi GPU Test 2 : Multiple context Single Thread
----------------------------------------------------------
Total time : 39.2678
Time of GPU0 : 4.6637
Time of GPU1 : 3.12808
Time of GPU2 : 3.13052
Time of GPU3 : 3.15125
----------------------------------------------------------
Multi GPU Test 3 : Multiple context Multiple Thread
----------------------------------------------------------
Total time : 40.339
Time of GPU0 : 4.57501
Time of GPU1 : 3.20865
Time of GPU2 : 3.12312
Time of GPU3 : 3.17568
Press any key to continue . . .

Above is the test result for SimpleMultiDevice.

My main concern is to use all four GPUs for computing, now I  simply change the "device[0]" to "device[1]" to see if this works. It turns out not working. So here is my question:

1): Is there any driver to combine the four GPUs to make them act as a more powerful one?

2): If not, can you point a way how I should harness them to imporve the computation power?

 Thanks again, I really appreciate it.

Thomas

[himanshu_gautam]

ThomasUCF,

Please run the sample SimpleMultiDevice with -e option. If you get a Pass Message for every GPU,then all your GPUs are working properly.In that case you can definitely use them.

[ThomasUCF]

Hi Humanshu:

  yeah,it says passed. Thanks a lot.

Thomas

[n0thing]

SDK 2.2 Developer release notes -

The ATI Radeon™ HD 5970 GPU is currently supported in single-GPU mode only. It is recommended users only access the first device on an ATI Radeon™ HD 5970 GPU for GPU compute.

[sergey_ilich]

When I can work on second GPU on 5970 ?

I saw test with options  there is veryfying results on gpu0-gpu3, and you say that it is working only device[0]

----------------------------------------------------------
CPU + GPU Test 1 : Single context Single Thread
----------------------------------------------------------
Total time : 63.9546
Time of CPU : 59.64
Time of GPU : 3.22437
Verifying results for CPU : Passed!
Verifying results for GPU : Passed!
----------------------------------------------------------
CPU + GPU Test 2 : Multiple context Single Thread
----------------------------------------------------------
Total time : 63.9546
Time of CPU : 53.0936
Time of GPU : 3.08569
Verifying results for CPU : Passed!
Verifying results for GPU : Passed!
----------------------------------------------------------
CPU + GPU Test 3 : Multiple context Multiple Thread
----------------------------------------------------------
Total time : 51.6011
Time of CPU : 49.377
Time of GPU : 3.06322
Verifying results for CPU : Passed!
Verifying results for GPU : Passed!
----------------------------------------------------------
Multi GPU Test 1 : Single context Single Thread
----------------------------------------------------------
Total time : 27.2769
Time of GPU0 : 3.04458
Time of GPU1 : 2.94096
Time of GPU2 : 3.07542
Time of GPU3 : 3.07895
Verifying results for GPU0 : Passed!
Verifying results for GPU1 : Passed!
Verifying results for GPU2 : Passed!
Verifying results for GPU3 : Passed!
----------------------------------------------------------
Multi GPU Test 2 : Multiple context Single Thread
----------------------------------------------------------
Total time : 30.2896
Time of GPU0 : 3.07658
Time of GPU1 : 2.91558
Time of GPU2 : 3.01686
Time of GPU3 : 3.05854
Verifying results for GPU0 : Passed!
Verifying results for GPU1 : Passed!
Verifying results for GPU2 : Passed!
Verifying results for GPU3 : Passed!
----------------------------------------------------------
Multi GPU Test 3 : Multiple context Multiple Thread
----------------------------------------------------------
Total time : 30.5671
Time of GPU0 : 3.05937
Time of GPU1 : 3.04916
Time of GPU2 : 3.02367
Time of GPU3 : 3.18991
Verifying results for GPU0 : Passed!
Verifying results for GPU1 : Passed!
Verifying results for GPU2 : Passed!
Verifying results for GPU3 : Passed!

[himanshu_gautam]

Currently you cannot use devices other then device[0] for computing.

[ThomasUCF]

 Thanks, yes I am using windows 7. I have two 5970s, so I have device[0],device[1],device[2],device[3], but only device[0] give the right result. Can you explain that?

 Thanks again.