There have been rumors that 980ti will have more vram. Then there is rumors that 980ti will have 4gb and a new version of 980 will have 8gb.

Normally manufacturers are not allowed to make custom vrama amounts.

NVIDIA does allow AIB partners to add more memory to their GPU's, usually at least a month or more after launch. The decision is based on what NVIDIA will permit/what the GPU will support.
 
The real question though is, what do you really gain with more memory?, when NVIDIA/AMD launch their cards, they put the maximum amount of memory on board before depreciating returns kicks in. Think of it like this, would a GTX 750 TI do better with 4GB or 6GB of ram?, I don't think so. About the only thing that "extra" memory does is allow games to have larger frame buffers/textures, but again that's on a per game basis and not on what the GPU can do, basically in situations like that, the graphics card runs out of GPU horsepower before it runs out of memory.
 
Something to keep in mind is that depending on the GPU used and its memory configuration (how many chips are on the board) will determine how much memory.
Ex, GTX 980/970 have 8 chips totaling 4GB, but there are clearly space left open for additional memory, so these could have 8GB with the same memory, just using all the "empty slots". But again, if the GPU doesnt have the horsepower to fully take advantage of that extra memory, its really just for fluff. Similar to how OEM's attach relatively huge amounts of memory to low end cards to make the numbers look better.
 
I personally do think we will see cards start to have more and more memory, pushed because of consoles, game dev's are using all the memory on the consoles (8GB on PS4/XBO), so I think we will start to see 6/8 GB become the norm really quickly. If you want a example of this, just Google some of the upcoming AAA games, and look at their minimum specs, most of which are saying 4GB MINIMUM video card memory, and 6GB recommended.
 

hawk269
I have a 4k display and I current have original 6gb Titan's right now and have played a lot of games that break through the 4gb use on my Titans, so that is why I am asking. 

 
Just because a program is allocating more than 4 GB of VRAM, that doesn't mean that it's actively using it.

My gut says that before the end of the year we'll get a 6GB 980 ti or a Titan MAX

I do remember reading an article that said there would be 8GB 980's coming out. Hang on let me have a rummage ... ahh yes here it is EDIT: Nope link got removed. It was an OCUK guy saying:
 

980 / 970 4GB reference cards with 8GB coming at a later date with custom coolers. Can’t say any more but don’t expect a huge leap in performance over current single GPU stuff.
Performance wise, my lips are sealed on how it compares to 780Ti, but of course 980 is quicker than 780 for sure!

 
He was of course wrong about the speeds though. Its a quote attributed to seminal UK Clockers, OCUK. It may be wrong, but I hope it isn't. My desire for more VRAM comes from wanting to run a triple monitor setup, or 5760 x 3240. I'd like to step up from the 4Gb to the 8 so I am wondering if OCUK were right (even if they may have been wrong to say it... depending on your POV...)
 
EDIT: And as if by magic, the WCCF site (from 15 hours ago) is carrying an 'authentic' sources' confirmation rumour (  )of 8GB versions in November. Would post link but I am guessing the forum eats them. Nom.

BabtridgeVonJoystick
I do remember reading an article that said there would be 8GB 980's coming out. Hang on let me have a rummage ... ahh yes here it is EDIT: Nope link got removed. It was an OCUK guy saying:
 

980 / 970 4GB reference cards with 8GB coming at a later date with custom coolers. Can’t say any more but don’t expect a huge leap in performance over current single GPU stuff.
Performance wise, my lips are sealed on how it compares to 780Ti, but of course 980 is quicker than 780 for sure!

 
He was of course wrong about the speeds though. Its a quote attributed to seminal UK Clockers, OCUK. It may be wrong, but I hope it isn't. My desire for more VRAM comes from wanting to run a triple monitor setup, or 5760 x 3240. I'd like to step up from the 4Gb to the 8 so I am wondering if OCUK were right (even if they may have been wrong to say it... depending on your POV...)
 
EDIT: And as if by magic, the WCCF site (from 15 hours ago) is carrying an 'authentic' sources' confirmation rumour (  )of 8GB versions in November. Would post link but I am guessing the forum eats them. Nom.

You could post them if you remove the http or www. at the beginning :) and then we can just add them back at the moment of searching. I'd love to read these articles, because I haven't purchased my 900 series cards yet, and this is exciting "news" (rumors).