特斯拉P4 ffmpeg性能不佳

大家好，
我们在带有Tesla P4的dell R740服务器中使用linux。
我们正在使用GPU对ffmpeg进行一些测试，没有使用GPU，我们得到了相当多的FPS，我们觉得很奇怪。
没有GPU
ffmpeg -i Samsung_UHD_Soccer_Barcelona_Atletico_Madrid.ts -threads 0 -map 0：0 -b 500k -c：v libx264 -s 320x240 -y test.h264
frame = 1068 fps = 77 q = -1.0 Lsize = 1282kB time = 00：00：21.32 bitrate = 492.5kbits / s speed = 1.53x
用GPU
ffmpeg -hwaccel cuvid -c：v hevc_cuvid -i Samsung_UHD_Soccer_Barcelona_Atletico_Madrid.ts -map 0：0 -b：v 500k -c：v h264_nvenc -pixel_format yuv420p -r 25 -vf scale_npp = 320：240 -y test1.h264
frame = 415 fps = 66 q = 39.0 Lsize = 1044kB time = 00：00：16.60 bitrate = 515.4kbits / s dup = 0 drop = 411 speed = 2.62x
另一个奇怪的事情是，即使我同时运行不同的进程，GPU的使用总是相同的....大约9％
utilization.gpu [％]
9％
utilization.gpu [％]
10％
utilization.gpu [％]
9％
utilization.gpu [％]
10％
utilization.gpu [％]
有没有人有ffmpeg来解释这个？
最好的问候和提前感谢



以下为原文

Hi all,

We are using linux in a dell R740 server with a Tesla P4. We are doing some test with ffmpeg using the GPU and without, we get quite much FPS without using the GPU, what we find weird.



Without GPU

ffmpeg -i Samsung_UHD_Soccer_Barcelona_Atletico_Madrid.ts -threads 0 -map 0:0 -b 500k -c:v libx264 -s 320x240 -y test.h264

frame= 1068 fps= 77 q=-1.0 Lsize=    1282kB time=00:00:21.32 bitrate= 492.5kbits/s speed=1.53x

with GPU

ffmpeg -hwaccel cuvid -c:v hevc_cuvid -i Samsung_UHD_Soccer_Barcelona_Atletico_Madrid.ts -map 0:0 -b:v 500k -c:v h264_nvenc -pixel_format yuv420p -r 25 -vf scale_npp=320:240 -y test1.h264

frame=  415 fps= 66 q=39.0 Lsize=    1044kB time=00:00:16.60 bitrate= 515.4kbits/s dup=0 drop=411 speed=2.62x




The other strange thing is that even if i put to run different processes at the same time, the GPU usage is always the same.... around 9%

utilization.gpu [%]
9 %
utilization.gpu [%]
10 %
utilization.gpu [%]
9 %
utilization.gpu [%]
10 %
utilization.gpu [%]


Anybody has experience with ffmpeg to explain this?

Best regards and thanks in advance