Training time of MAISI VAE

Hi, I am trying to train the MAISI VAE from scratch using my dataset. 
I wonder how long it takes to train on such a large dataset? 

When I use 30k CT scans, it takes nearly 20 hours for 1 epoch on two A100. Is it correct? I use DDP, but I found it was even slower when I increased the GPU number.

If so, is there any method to accelerate the training process?
