Is cards like a gtx 770 4gb vram limited by it's bus speed?

[gasolin]

Came across something to me interesting, i had a amd 3gb gpu, used more then 2gb vram in crysis 3 not shure about bf4 (mis afterburner didn't work in bf 4 64 bit with osd)and skyrim is surpose to use more then 2gb vram ALL IN 1920x1080 so 2gb vram might not be enough for a hand full of games in 1920x1080.

So for my 2560x1080 monitor i need more then 2gb vram, so i first looked at the gtx 760 4gb from msi which is a extremly silent card(2gb version) no one has it, out of stock and i have read the it can't use the whole 4 gb of vram, so i ordered a gigabyte gtx 770 oc 4gb, just to find out some one say even a gtx 770 is not able to use more then 2.5 gb and can't use more vram because of a 256 bit bus limited.

Is gtx 770 4gb and other similar cards limited to how much vram it can use,utilize by it's bus speed (256bit), not shure if i need more then 2.5 gb vram (don't surgest me to get a amd card i am going from amd to nvidia)

If that is true why is there so many gtx 660/660 ti 3 gb,gtx 670 4gb,gtx 680 4gb, gtx 760/770 4gb (asus dosn't make 4gb version of the gtx 760/770)

http://linustechtips.com/main/topic/76184-why-not-to-get-the-760770-4gb/

 

[Coal Felpz]

Not quite sure if that is all cards or just the few in your case.
What I can tell you is I am planning on buying an AMD Radeon R9 280x with a dedicated 3GB which can apparently handle BF4 on Ultra at 1080p with all AA and MSAA on max. I believe the R9 290x is also available with more vidmem, if you are looking for something with more performance and GB.

 

[gasolin]

(don't surgest me to get a amd card i am going from amd to nvidia) Not compatible with physx (think it looks a bit better using a gpu then a cpu) and dosn't support g-sync, feel nvidia are a bit more quiet the amd even with the same cooler.