Difference between short and long GPUs?

I recently bought an EVGA 660ti

http://www.newegg.com/Product/Product.aspx?Item=N82E16814130837&Tpk=evga%20660ti%20signature%202&IsVirtualParent=1

and my friend bought a Zotac 660ti

http://www.newegg.com/Product/Product.aspx?Item=N82E16814500269

I was wondering what the actual difference was, since mine was significantly longer, yet had very similar (albeit slightly better) specs, the same amount of fans, only $10 price difference, etc... what are the differences in performance? Feel free to criticize the cards too, cause i'd love to know what people think about either, but what i mainly want to know is; does size matter?

No, size does not matter, it all depends on the GPU. 

Size does matter.

1. Bigger die means you need more realistate. The die for the TITAN is huge, thus requiring more space.

2. More complicated dies requirmore realistate. The TITAN has the most complicated single core, that core depends on alot of other components including power phase, for cleaner power, mosfets, various resistors, Vram chips (the titan has some on the back).etc...

3. Potential better cooling having a longer card means that you will have more thermal mass allowing for better cooling, this can be avoided by a watter block though, as the thermal mass it now somewhere else.

Alright! thanks alot! so what im seeing is for the same GPU, the size doesnt affect performance, except for perhaps overclockability because of temperature (maybe). 

good to know :0

Yah, the only thing I can think of is cooling and having the space for a double or triple fan cooler and a bigger heatsink.  Maybe two GPUs on the same PCB but that's not nearly as common as it used to be.