Could you share the script run command, I assumed it is just python scripy.py
do I have to use any specific flags or CUDA env variables that need to be set.

I was actually using the exactly same script as shown in that tutorial. It is a .rst instead of a notebook because I don’t know what the hardware spec of our tutorial servers will be. I would like to avoid tuning parameters every time the underlying server hardware changes. I probably should have highlighted in the very beginning saying that the result will be different in different envs, and each env would require efforts to explore configuration space to get the best perf. 
I did that a while back, and my server env should be either this:
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 396.69                 Driver Version: 396.69                    |
|-------------------------------+----------------------+----------------------+
| GPU  Name        Persistence-M| Bus-Id        Disp.A | Volatile Uncorr. ECC |
| Fan  Temp  Perf  Pwr:Usage/Cap|         Memory-Usage | GPU-Util  Compute M. |
|===============================+======================+======================|
|   0  Tesla M40           On   | 00000000:0B:00.0 Off |                    0 |
|  0%   27C    P8    18W / 250W |      0MiB / 11448MiB |      0%      Default |
+-------------------------------+----------------------+----------------------+
|   1  Tesla M40           On   | 00000000:0D:00.0 Off |                    0 |
|  0%   25C    P8    18W / 250W |      0MiB / 11448MiB |      0%      Default |
+-------------------------------+----------------------+----------------------+
                                                                               
+-----------------------------------------------------------------------------+
| Processes:                                                       GPU Memory |
|  GPU       PID   Type   Process name                             Usage      |
|=============================================================================|
|  No running processes found                                                 |
+-----------------------------------------------------------------------------+

        GPU0    GPU1    CPU Affinity
GPU0     X      PIX     0-11,24-35
GPU1    PIX      X      0-11,24-35

or this:
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 418.116.00   Driver Version: 418.116.00   CUDA Version: 10.1     |
|-------------------------------+----------------------+----------------------+
| GPU  Name        Persistence-M| Bus-Id        Disp.A | Volatile Uncorr. ECC |
| Fan  Temp  Perf  Pwr:Usage/Cap|         Memory-Usage | GPU-Util  Compute M. |
|===============================+======================+======================|
|   0  Quadro GP100        On   | 00000000:81:00.0 Off |                    0 |
| 26%   32C    P0    29W / 235W |      1MiB / 16278MiB |      0%      Default |
+-------------------------------+----------------------+----------------------+
|   1  Quadro GP100        On   | 00000000:82:00.0 Off |                    0 |
| 26%   33C    P0    30W / 235W |      1MiB / 16278MiB |      0%      Default |
+-------------------------------+----------------------+----------------------+
                                                                               
+-----------------------------------------------------------------------------+
| Processes:                                                       GPU Memory |
|  GPU       PID   Type   Process name                             Usage      |
|=============================================================================|
|  No running processes found                                                 |
+-----------------------------------------------------------------------------+

	GPU0	GPU1	CPU Affinity
GPU0	 X 	NV4	12-23
GPU1	NV4	 X 	12-23