Fan size fail

Oh.... and while you are at it.
Any preferences on which fan to pick?


Another thing I'd like to say:

I have read some discussions about the akasa exhaust being junk. NO fing way! I got a ~10°C drop on my GPU.

A simple tape measure will show you the diameter of your fan (side to side) is 80mm, it may be that you need a 92mm fan or 120mm, some cases have screw points for all three sizes at the rear mesh
Moto

Uploaded with ImageShack.us

I did that. I measured it. You do not understand me:
The green line, and the red line are different. Which measurement is correct?
Don't get me wrong, I COULD get up, and walk to my garage, get a tape measure, walk back, and check whether the diameter (green line) matches one of the standarts, and walk all the way back to the garage, and get back here......

Buuuuuuut:

Which line is the one I have to look at when buying a fan? Since 80mm (red one) was too small, I am guessing the diameter (green line) is the one fan size means.

The redline is the measurement you are concerned with as that is the diameter of the circle, if you want an 80mm fan, that is the measurement that should be 80mm, on an 80mm fan the greenline measures 110mm btw
Moto

The green line in a square would be a√2. Considering that my a is 80mm, that would than be 80√2 which is not 110mm.

it would be 113mm *sigh* Ur right, I'm wrong. Srry, never mind that.

Instead tell me how can my fan than be too small? It is 80mm, but looking at the green line (diameter) it lacks like 1,5cm.

your green line is about 100mm?
in that case I think its a cpu fan that should sit on a standard sized heatsink, mines slightly smaller than the 80mm fan I have mounted on top of it so I think the redline on mine would be about 76mm, those fans wont fit into an 80mm case hole, put it over your cpu fan (if you have standard heatsink ofc) just to doublecheck its same size or not.
Moto

It does indeed fit the stock CPU fan size. But the shop said it was 80mm.

So, tell me, what size should I now take?

Go back to shop with the fan and any packaging you kept/dig out of the bin, beat assistant over head with said fan until he/she replaces it with the correct size for you.
take your tape measure to be certain cause you know now which measurement you want and explain to them how frustrating this has been for you, might get a bit of discount if your lucky  
**Edit, the fan you want is 80mm side to side (Red line) and 110mm ish on the diagonal (Green line)**
Moto

Well, I don't want to take the fan back, because I have just spent the last 2 hours raging and berserking over my PC case, with a hammer, 3 screws and a big plier. You don't even want to know how I got the fan into place. But it is there now.

And I rather doubt it will come out again. -like, ever.

But! I still haven't put my tools away, and I think a hit with a hammer/plier would be much more effective, don't you?

With a bit of luck, I'll get one for free!

HAHAHAHA!! You went viking style on your pc. Totally badass!

But it is true, what the other guy said, I used just to kick my old pc which didn't work. No cure like 3 hard kicks! It worked like a charm than, for the next hour or so. XD

Best answer selected by iZver.

Glad you like it   and thank you for B.a.
Moto

Cheers