FPS is too high (3870) in train.logs for SVTR tiny

[Ashish0091]

In train.logs the fps is 3870 for SVTR-tiny . How it is calculated and why it is too high. I calculate FPS image wise and avg FPS is coming around 34.

I tried to calculate FPS something like this:
import time
t1 = time.time()
pred = model(img) # model inference (only for example)
t2 = time.time()
print('FPS is',1/(t2-t1))