haqqaton said:
I know the difference between primary (RAM) and secondary (HDD, SSD, etc.) memories. What I'm trying to tell you is that is possible to build a computer with only a SSD, for example. I mean, without RAM or any other memory. A Turing Machine is just that, actually. The memory hierarchy in a computer is there only because of speed's differences. Your HDD can be used as RAM and.. it is! That is called swap area: when you're low on RAM it is used to store the least used pages (paging). So yeah, you can build a custom computer (or console, it's the same) that has no RAM at all. So.. The RAM is only necessary because disks are too slow. The RAM memory is, roughly speaking, a cache for the slow disk. "Terms for data being missing from a higher level and needing to be fetched from a lower level are, respectively: register spilling (due to register pressure: register to cache), cache miss (cache to main memory), and (hard) page fault (main memory to disk)." Source: https://en.wikipedia.org/wiki/Memory_hierarchy By the way, your Battlefield 1 example can't be used here because it's a "generic" built to run on any PC. It's not like a game built to run only on console X or Y. Consoles have fixed hardware. ------- From now on, MB = Mebabyte and Mb = Megabit MB/s = 8 x 10^6 bytes per second Mb/s or Mbps = 10^6 bytes per second ------- Backing to our main point, I'll use a very simple example this time: Let's say I'm a game developer and I want to make a very neat pause menu screen for my game but I want to play an animation everytime it is called. To make things harder, I want to choose the animation out of other six different possible animations (random) to be played every time the player pushes START. So, I have six animations in total and every anymation is S megabytes in size. For this example, let's compare a console using discs (D) with another using cartridges (C). D uses a Blu-Ray in 2x and can read up to 72Mbps, which is 'good'. But let's not forget that it can take a LOT (a LOT LOT, really) of time to move the laser to the right position of reading (sequential memory - slow) C uses cartridges and can read up to 70 MB/s. OK, so C can read the same data 10 times faster than D from the media (considering the time for moving the laser). Let's say that it takes 0.001 second to load the S megabytes for my animation from the RAM instead of 1 second from the Blu-Ray. Now, in D I would pre-load all my animations (8 * S) on the RAM to use it when the player calls the menu as I don't know yet which animation will be used in the next pause screen. If I try to load it on demand from the Blu-Ray, my pause screen would take too long to load and my game would receive bad reviews for it. Look, I'm using RAM as a cache!! Now, let's say that it takes 0.1 second to C to load my animation from the cartridge (it's 10x times faster anyway). I don't really need - but I could if I wanted - to use the RAM as a cache anymore. I can load my animation on demand from the cartridge because it is fast enough to not get bad reviews for my sluggish pause screen. Now my game is using less RAM while executing the same game. Can you understand what I'm trying to say? The speed of the media takes to different usages of the RAM. When using a slow speed media, I must use more RAM as a cache than when using a faster media. In that case, I would need to pre-load thing more often. So, again... The RAM has to do with the media. =) p.s: I really like that Dumb and Dumber scene. It's motivational. |
This is kind of a no shit sherlock... yes, in theory you can build a machine without RAM, it just won't be a gaming machine.
So why exactly bring it up when we are discussing something as specific as a console?
It would be too long of a post to go through every minutia, so let's just get the short version...
Your example of the media being loaded off the cd is pretty much invalid as every modern console will install the game into the drive for quick access to the game assets. That goes exactly into my previous point of having a faster hard drive having a benefit on LOADING TIMES. That is it and that is all.
If any game developer is reading this, please feel free to correct me in case I'm saying something wrong, but the RAM needs to hold the most immediate resources for what current level of the game is being played are. If the game needs to go back to the storage (hard drive, sd card, bluray, etc) to pick up new resources the game either will stop to load those same resources into the RAM or just simply glitch out.
There is simply no way in hell you can give the tasks of the RAM to the storage media unless you ran out of RAM. The developer would simply program the game around the RAM limitation and make sure they will only load exactly as many resources as they are absolutely needed in order for the game to play. This can simply mean lower resolution textures, fewer objects, etc.
So please let's stop with theoretical scenarios and just look at things realistically. And that means, no, having a faster ssd/sd card, will not compensate for some lack of RAM while running a modern game.
