why my net time of demo.py is different from test.py ?

[yujiongzhang]

I run dla_34 ctdet model on t4 and the inference time when I run test.py.

default |############################### | [1054/1056]|Tot: 0:02:09 |ETA: 0:00:01 |tot 0.122 |load 0.068 |pre 0.014 |net 0.038 |dec 0.001 |post 0.001 |merge 0.000
default |################################| [1055/1056]|Tot: 0:02:10 |ETA: 0:00:01 |tot 0.122 |load 0.068 |pre 0.014 |net 0.038 |dec 0.001 |post 0.001 |merge 0.000 

but the net time is different from that in demo.py .

tot 0.153s |load 0.080s |pre 0.018s |net 0.053s |dec 0.001s |post 0.001s |merge 0.000s |
tot 0.152s |load 0.080s |pre 0.018s |net 0.053s |dec 0.001s |post 0.001s |merge 0.000s |

Do you know the reason why thenetin test.py is 0.038, but in demo.py is 0.053?

If I want to test the fps of my model, should i use test.py or demo.py?