He means 384 shader processors. (Graphics cards are massively parallel compute devices and he's implying your's only has 384 shaders while his card has 800 of them. It's all those parallel processors all working at the same time on different parts of the 3D image at once that make the generation of complex 3D graphics possible in real time.)
I used the 800 shader card for 18 months to test the closed then open alpha. GTX 650 were constructed with 384 shaders. 650TI and TI Boost were increased to 768. If he had either of the latter he would not be reporting as many issues.
The game has come down to:
Type of Video ram.
Data paths.
Band width.
Number of shader processors.
I have had the opportunity to test the game with a GT 9800, HD 6770, and now a GTX 760.