Hello everyone !
Just sharing my own GTX 1080Ti results for @jeremy “mnist.ipynb” notebook from Lesson 4 (BatchNorm + Dropout + Data Augmentation) he was running on last-gen GTX TITAN X.
In the last 12_epoch run (cell #85), I get 9-10 sec per epoch vs. his 13-14 sec so a basic 30% speed gain.
My rig is a former gaming PC from mid-2015:
- Gigabyte Z97X motherboard with 16Gb DDR3 1866mhz (reused from a 2012 rig ^!^ )
- Intel I5-4690K 3.5Ghz, not overclocked
- Corsair CX 650M PSU
- Samsung SSD Serie 850 EVO -500Gb + WD Purple -3Tb
- Asus GTX 1080Ti Founder Edition
- Corsair Carbide 100r Silent Edition
- Dual-Boot Win10 + Ubuntu 16.04 (for Fast.ai part 1)
Cost of hardware in 2015 + assembly: 1000 euros
GTX 1080Ti: 700 euros
Obviously the RAM is supposed to be sub-par and the CPU is nothing close to an i7-7700K (which shouldn’t be overclocked BTW, dixit Intel now - ouch for the K 
but it still delivers pretty well imho.
Note: it’s crucial to drop the CUDA backend and switch to Gpuarray if you still get the pink warning when loading the notebook.
That alone cut epoch time by more than half (like 24sec down to 10 sec).
Last thought: I prefer the Founder Edition or so-called Aero version of the GTX 1080Ti because its airflow is expelled out of the case via its own rear panel = less work for my case’s exit fan.
At full load (100% GPU and 70% CPU) on several 200sec * 12 epoch, I read 87°c on the GTX 1080ti and 67°c on i5-4690K on Psensor.
Anyone planning multiple GPU’s in one case may want to look into this: if you have gaming GPU’s with their triple 92mm fans running at full speed inside the box for hours, you’ll need some serious airflow to exit the heat and a single 140mm case fan won’t cut it.
Cheers,
EPB
PS: if I was to rebuild this rig today, I would only spend 100€ extra on a motherboard capable 128gb RAM vs. 32gb max, and a stronger Corsair PSU like CX 850W capable of dual GPUs.