The only way I can really see a benefit is is you have a bottom mounted PSU and a decent amount of airflow up. Remember, the point of airflow is to have a good Intake to Exhaust path that isn't disrupted badly.
Either way, unless your total airflow is rather poor, you probably won't see any decent gains over the standard, in the front and out the back.
Well here's the issue in any respect. You need a "flow" of air. With the exhaust going out, it's taking hot air out of the back of the case. Bringing air in will bring air off of that PSU (heat rises) and back into the CPU. So you're already getting probably above ambient temperature. Now, if you have a proper airflow setup; you'll have crisp ambient air coming in at a rate much greater than if you did that. So weigh the variables here. Is your airflow going to be good enough to keep ambient temperatures in the case within 2C of the ambient air of the room? In my case I have 3 230mm fans, one in the front, one on the side and one on the top. My case temperature is usually exactly the ambient out in the room. So if you have good ventilation like my Thor V2; there is no need. Last but not least, if you're blowing air into the case from the back; it's pushing that hot air from the HSF into the case. So you'll need even more ventilation to compensate.
I hope this helps out. I'd suggest trying it and seeing what happens. But most likely; it's going to cause hotter internal temperatures and have no benefit. But that's the point of trying it you know? How will you ever know if you don't "give it a go"? That's my saying; so give it a shot and see if it does do any good. Just remember to try it both ways and compare under similar circumstances!
right, i see what ur sayin, ill have cool air coming in from the front, rear, and bottom, and exhaust out the top. im not doin any cf or sli and ill have room in the case... ill have cool air coming str8 in for the cpu and right up and out with the top exhaust and bottom fan pushin up
It might do some good and it might not. Remember, since the PSU is mounted on the bottom it's going to exhaust out of the back and it's going to rise to that vent spot. If that air is colder than what's in the case; it "could" be beneficial. If it's not; then it's going to be counter productive. Either way; like I said. Experimentation is what leads to new ideas and methods! So experiment at little and see what you can come up with. Though the generic setup is usually the best on the average case just so you know.