That's normally the way it's done but as I think about it, if the fan is above the level of the GPU it might be a good idea to exaust it since the hot air will rise. If it's below the level of the GPU, keep it intake to feed fresh cool air to the GPU fans.
I totally made that up and no idea if it matters. Can just try it both ways and run benches to see what happens.
I have a CoolerMaster Centurion case, with 650W psu coming along with it. It is kinda 3 years old. But I take care of the system good. No dust lives inside lol. And I have a really good cable management as much as the case lets me in. Since it is oldish it doesnt allow you to take cables behind the mobo but I have lots of space under the top optical drive and stick them there hehe.
I have CM Hyper212X running push-pull, a xigmatek 1500rpm fan 120mm as rear exhaust, coolermaster 1000rpm fan 120mm as side intake, and a 80mm 1000rpm front intake coolermaster too.
I tried intake and exhaust for the side fan, after letting the gpu to cool off and realized that Exhaust is not a good idea. It wasnt reaching 77C before, now it does lol. At least with intake I was barely reaching 75C, usually was staying around 73-74C.
So I'm guessing I'd stick to intake or maybe to remove it ? have no idea actually...
I'm also guessing those double axial fans on gpu work as exhaust yeah (from chipset to bottom of case)? Or they are also intake and push air towards the edges of gpu through the chipset?
any ideas are welcome lol. I have no idea... hehe
With a high flow exhaust in the rear and limited front intake there's a natural negative pressure in the case, a situation made more severe with the side fan as an exhaust (too much out, not enough in) hence the temperature increase with the side fan as an exhaust.
You could try this: Add a high flow 120m.m. front intake fan and disconnect the side fan.
Those graphics card fans blow into the card, down onto the PCB BTW.