What does RAM on a GPU do?

[Ezra]

What the title stated.

I'm considering buying an ASUS GTX 770 and one of them has 2GB and another has 4GB but I have no idea what they do for the card or how it affects the games I'll be playing. Can someone explain this to me?

[Ezra]

Can you explain how it gets a bit more in depth? I'd like to know a lot of details about this before I make up my mind on what I should buy.

My resolution is 1920 x 1080, so the 4GB would perform much better from what you're saying, does that mean I should get it?

[Titanicium]

Can you explain how it gets a bit more in depth? I'd like to know a lot of details about this before I make up my mind on what I should buy.

My resolution is 1920 x 1080, so the 4GB would perform much better from what you're saying, does that mean I should get it?

 

1) For 1080p you will really not need anymore then 2GB. It simply just win´t that many textures to "store". Same principle as you will never need more then 8 GB of system RAM if you are just gaming (no tabs or programs in the background) because the game doesn't have enough to store

 

2) More VRAM doesn't automatically mean more performance. It's the same principles as system RAM again. Without it everything you run will be F-ed, but too much doesn't increase performance.

 

3) The 770 doesn't have a big enough memory bus to support the 4 GB so the 4 GB of the card is just to lure people to buy it (cheap from Nvidia's side indeed). Memory bus is very much like the frequency of system RAM. If you need to transport a lot of data in a short amount of time you need more MHz, but if you don' then you will be fine with less

 

In order to support 4 GB effectively you will in theory need a memory bus of 512 Bit while the 770 got a 256 GB bus. Ergo: it can only effectively support 2 GB which is what the card natively comes with So yeah: Don´t buy the 4 GB version.

 

If you need more info then please say, but I am in class (teacher thinks I am working like mad on the short story we are supposed to write ) now so it might take a while for me to write some more… Hope I helped never the less

[Guest Gazzer96]

Its like ordinary RAM; it allows the GPU to quickly access all the data it needs to make the image on your screen, but if it runs out of RAM it start taking things right out of the hard drive causing the game to lag A LOT because hard drives are slow compared to RAM. 2GB of VRAM is not really advisable anymore, so maybe you should get the 4GB version if you plan on having high detail from the next gen games.

[voaz]

More vRam (4gb vs 2gb) is only a must when you game on 1440p+

[Bloodyvalley]

The more vram = the higher you can put AA.

Also if you play on a high res, it is beneficial. But remember: the memory bus cannot bottleneck it. Think of it as a highway. If you have a 256 bit bus, that means you have 256 lanes. The more lanes there are, the faster your data is transferred.

[xToFxREAPER]

everyone explained pretty well. i will note though that if your planning to play skyrim with a lot of mods its really easy to need more then 2gb vram at 1080p.. i hit 2.5gb vram usage almost all the time sometimes way more

[Ezra]

Hmm okay so the amount of GB in a GPU is just used store textures? What if I play in an open world setting like Skyrim or something, wouldn't I benefit from having more GB to store more textures that are in the game?

[CwGoh]

Hmm okay so the amount of GB in a GPU is just used store textures? What if I play in an open world setting like Skyrim or something, wouldn't I benefit from having more GB to store more textures that are in the game?

If the textures are higher quality, have more AA, they will take up more space. But you will only see performance drops when you fill up the card past 2GBs, as the system will write to your OS drive, which is much slower than the GPU's VRAM.

[Hoppa]

When you start a game, the loading screen you see takes things like texture files, 3d objects and holds them in the vram.

And because vram is clocked a lot faster than standard ram, also physically closer and easier to access....  it makes it more efficient and quicker to show you the things on the screen.

 

Let's just say you're playing stock standard skyrim, and the majority of texture files are a 1024x1024 image. But then you download a high res texture pack and all the texture files become 2048x2048 images.

The vram had to hold the same number of textures but since the new textures are 4 times the size, it's going to take 4 times the amount of room on your vram.

And sometimes that surpasses the vram capacity. So when that happens, the gpu has to grab the texture file from the HDD to display on screen.

Although it may start storing it in your system ram, not fully sure on that one.

 

Having a higher resolution on your screen doesn't make the textures on objects higher quality. The textures will remain the same resolution.

The problem is that the gpu has to render a lot more pixels for every frame it creates.

 

These days, games are starting to more gpu intensive, even at 1080p resolutions.

This means that a 2gb card is starting to become not enough for some games.

So I'd say now that 3gb for a gaming gpu should be the standard (assuming you want to play games on max settings)

But you could still have a good gaming experience with a 2gb gpu.

 

Just my 2 cents.