Air flow when front fan is not available

I would sooner cut a holes in sidepanel for 120 fan or 2x120 than buy new case...

buying new *** is like being defeated by that stupid case...

If it was 60 C I would worry. 43 C is nothing to worry about.

Its not CPU but south bridge I am worried about... I can't hold finger on it and review of my board ASUS M4A785TD-V EVO mentioned that it could get quite hot on that passive. Thats why I am concerned with overall airflow.

I'll test how it will go with front/back even if it does not have ideal vent holes.

Bump on the hacking cases approach  
Mark the four screwholes for the 120mm, drill them, then either cut a hole out for the fan or drill a gazillion little holes, if you want to make it tidy, get a grill or filter that mounts on the outside of the case to hide them a bit  
Moto

There will be no cutting for now  

I seriously underestimate the power of exhaust fan. I never would imagine such a results, I always thought its logical that blowing cool air inside would be better, but then I browse around here and found thread where people voted which one is more important, "exhaust>intake" won.
So I tried and here are the results.


Prime95 test

---------------------------------------------------------
closed case, back fan as intake, none frontfan
---------------------------------------------------------
20min 30min
---------------------------------------------------------
cpu 61°C 63°C
mobo 47°C 47°C
--------------------------------------------------------

30 minutes of idle, after the test

cpu 38°C
mobo 40°C

--------------------------------------------------------
closed case, back fan exhaust, front fan intake
--------------------------------------------------------
20min 30min
cpu 56°C 57°C
mobo 29°C 29°C

After the test, right now its cpu 35°C and mobo 30°C

The motherboard temperature is kinda puzzling. My guess is that prime does not put any load on it, or something. And that high temperature it got from first measurement is from accumulated hot air? seriously dunno...
It got hotter with a movie more than prime(I am using onboard graphic card for now, so aero in win7 might be the reason)


Anyway results are really surprising to me. Either the air from front gets there much easier than I would thought, or its the pure power of exhaust fan. Can probably test if I disconnect front one, but thats for another time.

I was about to chime in with putting that rear fan , BACK to exhaust. That is the probably the most important fan, next is the top exhaust. The side fans, meh. Its easier and effective to get a flow going front low, rear/top high. It how heat works (obvious), it rises.