PC, PS4 comparison Unreal Engine 4

[sieanr]

ethomaz said:

sieanr said:

And the GPUs VRAM is the only thing being used to draw what you see on screen. Thats it, 2gb for all those textures, lights, particles, ect.

The main RAM in a computer is used by the CPU, and only the CPU. To give you some point of reference, crysis 2 uses about 800mb of system ram., ie what the CPU is using.

Battlefield uses ~1400MB... now get the PS4 4GB RAM unified and remove the OS part (1GB?) and you have 3GB for the game.

I'm pretty sure the Elemental Demo uses more than 3GB RAM (GPU + CPU).

What are you not understanding about this.

VRAM, that is attached to the GPU, is what the GPU is using to draw everything you see on the screen. Literally everything; every texture, model, particle, ect and the frame buffer. In the case of the GTX 680 that is 2gb, which means the most that it can be using for every assest you see on screen is 2gb.

Now how much system RAM is being used is who knows how much. You cited battlefield at 1400mb, and I'm going to assume you are referring to BF3. In that case, BF3 is using around 1400mb in VRAM. Hey, what you are saying is ture this time! sorta.. This is not system ram but the VRAM on the GPU, and BF3 uses around 700-800mb of system RAM attached to the CPU. Get it? Thisgives you a total memory usage of around 2gb, 1.4gb on VRAM and .8gb on system ram.

I'd be shocked if a demo, which may very well be using all 2gb of VRAM is using over a gig of system RAM when a complex full featured game like BF3 comes nowhere close.

 

But again RAM is going to mean jack when the PS4 is playing a demo like this. Fill rate, pixel shader rate, ect are the bottlenecks rather then ram, and there is nothing you can do to magically get around those fillrate limits.