Crytek: 8GB RAM Can Be Easily Filled Up, Will Surely Be Limiting Factor on PS4/Xbox One

[VanceIX]

zarx said:

VanceIX said:

There is something called "latency". You cannot instantly call everything from the RAM, it still takes time to do the request.

Latency has nothing to do with how full the RAM is. Again the point of RAm is that the latency is the same regardless of how the memory is ordered. The latency of a memory access will alwayse be roughly the same.

Unless you are talking about badwidth, which I guess given your "instantly call everything from the RAM" comment you are actually referring too. Of course reading 5GB of data from memory will take longer than reading 5MB. That is decided by memory bandwidth which for the PS4 for example is 176 GB/s which means each second you could read all 8GB of RAM 22 times every second. Of course having more data stored in RAM at once doesn't actually mean you have to use more bandwidth, it's actually the opposite. If you are using paging and swapping stuff into and out of memory constantly that consumes bandwidth. If however you fill all available RAM with data you don't have to swap out as much because more is pre-loaded. And for example for each room in a game if you only keep the lets say 1GB of textures and models etc you need in memory and then for the next frame you unload the lets say 100MB of textures you don't need and load in 200MB of new assets you need that takes extra time and bandwidth that you could be using for other things like say frame buffer effects, however if you pre load all 5GB (both consoles reserve around 3GB for the system so games only get around 5) of assets for the entire building you then don't have to waste bandwidth loading and unloading assets each time you move to a new room. And boom you have made your game more optimised by eliminating redundant asset loading and filled up all available RAM.

Just loading an asset requires capturing it from the hard drive, which is another background process that is happening. In massive open world games, it is very hard to pinpoint exactly what the user will do, you can't just preload the next room and hope it's enough. Like I said, it may be a viable strategy in linear games, but with any games that give you a choice it is a poor use of resources, as calling in the 5gb of information still requires sorting through the hard drive to find it and load it to the ram for fast use later.