Looking ata few late 2011 MBPs but I have a question.
Is VRAM used primarily for screen draw stuff etc? I will be using this machine to do some moderate 3Dmodeling and rendering, but won't CPU speed and RAM have a bigger impact on that than VRAM? I know the GPU can help with open cl interactive rendering but I am not sure how much of a part VRAM actually plays in that.
Close to pulling the trigger on one but I can keep looking if the GPU VRAM is critical to my usage. Otherwise this thing is stacked with SSD and 16GB RAM and anti glare screen
VRAM these days is a generic technical term to refer to the memory that is directly coupled to the graphics processor, usually through some high bandwidth channel. A portion is always used for the frame buffers - xRes*yRes*4bytes for 32bit colour * number of buffers - but while that is critical the vast majority of VRAM is spent on 3D functions (storing textures, vertex info, AA processing, etc).
Basically, it's like an "L0" cache - it's the fastest memory for the processor to work with. If you run out of VRAM, the processor needs to start swapping data in and out from main memory (the 8-16GB DDR3 RAM) which is slower both because of the bandwidth and the fact that there are other, non-graphics aspects using it constantly. Some game consoles go even a step further, building large on-chip caches (when on chip you latency goes up and bandwidth goes down) in addition to whatever VRAM they use, simply because having enough fast, local memory is so important.
tl;dr it's hugely important for 3D but not super important for daily use...though it's probably more important as screen resolution goes up and screen rendering performance goes down.
...all of that being said if you're doing modelling there are a variety of situations that stress different aspects of your machine. If you want faster real-time rendering, you'll like more VRAM. But if you're not using openCL or playing more intensive games, then the CPU comes into play more. It depends on the app and what you use it for...
