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For the same task, why is the execution time of GPU much longer than that of FPGA

HYB
Beginner
1,139 Views

For the same task, if the device is changed from FPGA to GPU, the task execution time increases from 3 to 73.The code is in the attachment. Please help me analyze the reason.

 

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6 Replies
AlekhyaV_Intel
Moderator
1,121 Views

Hi,


Thank you for posting in Intel Communities. Unfortunately, we couldn't find any code attached. Could you please re-attach it and share all the steps you've done?


Regards,

Alekhya


HYB
Beginner
1,108 Views

build.sh 

dpcpp -DFPGA_EMULATOR gpu.cpp \-c -o gpu.o
dpcpp -DFPGA_EMULATOR gpu.o -o test

 

run.sh

./test

 

qsub -l nodes=1:gpu:ppn=2 -d . build.sh
qsub -l nodes=1:gpu:ppn=2 -d . run.sh

cat run.sh.o.xxxxxxx

GRN2
Employee
1,084 Views

FPGA emulator is not real FPGA. Actually it's CPU binary.

AlekhyaV_Intel
Moderator
956 Views

Hi,

 

We reproduced your issue from our end and we could observe that you've used -DFPGA_EMULATOR flag while compiling the code. By doing this, FPGA emulator executes the dpc++ device code on the CPU. The FPGA emulator device supports FPGA extensions such as FPGA pipes and fpga_reg but doesn't compile your code on FPGA hardware. The FPGA emulator's timing behavior is not correlated to that of the physical FPGA hardware. For example, an optimization that yields a 100x performance improvement on the FPGA may show no impact on the emulator performance. The emulator might show an unrelated increase or decrease. For more information on types of DPC++ FPGA compilation, please refer: https://www.intel.com/content/www/us/en/develop/documentation/oneapi-programming-guide/top/programmi...

If the above information resolves your issue, make sure to accept this as a solution. This would help others with similar issue. Thank you!

 

Regards,

Alekhya

 

AlekhyaV_Intel
Moderator
875 Views

Hi,


Has the solution provided helped? Could you please give us an update regarding this issue?


Regards,

Alekhya


AlekhyaV_Intel
Moderator
802 Views

Hi,


We assume that your issue is resolved. If you need any additional information, please post a new question as this thread will no longer be monitored by Intel.


Regards,

Alekhya


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