A shed load... I google searched and found this...: http://www.hardocp.com/article/2015/03/10/dying_light_video_card_performance_review/10#.VqvElLIrK70How much Vram does Dying Light use maxed out?
@ 2560x1440 it maxed out the 4GB on a GTX 980.
In the table above you will see all of the video cards we tested today and the maximum utilized VRAM capacity in Dying Light at said resolution with maximum game settings. By maximum game settings we mean "Best Quality" global option and then raising Shadow Map Size to "Very High" and View Distance to maximum.
In all cases above you will note all video cards are hitting maximum capacities possible. The GeForce GTX 970 maxed out at 3.6GB, we could not get it to run above this, even at 4K. However, as we indicated, Dying Light was playable at 1440p without stutter. Specific optimizations have gone into this game for the GeForce GTX 970 as of the 1.3.0 patch.
The issue to focus on however is that all of these video cards are hitting the maximum capacities in Dying Light. This game demands high VRAM capacities to alleviate stutter. We found that in VRAM limited situations the game would stutter when being grabbed by zombies, or having to combat zombies. There would be a hang, or pause, or freeze if the resolution was too high for the video card.
For example, at 4K this happened on the GTX 980 and R9 290X, the 4GB of VRAM wasn't enough at 4K. On the 2GB video cards trying to run them at high setting sat 1080p also caused stuttering. That's right, even 2GB video cards had limitations at 1080p when trying to run higher settings.
Our recommendations, based on our experiences, lead us to recommend these VRAM capacities for the best enjoyment of Dying Light.
1080p - 3GB VRAM Video Cards
1440p - 4GB VRAM Video Cards
4K - 6GB+ VRAM Video Cards
This is a huge open world, there is a lot of detail in Dying Light. Running "High" textures, and "Very High" Shadow Map with "Maximum" View Distance will eat into your VRAM big-time.