Why slow cards don't use much memory

[cst1992]

Hey, everyone.
I was just looking at the reviews of a 660 on newegg, and the guy said the card has 2 GB of RAM, but doesn't efficiently use it. It goes above 1.5 GB of RAM, but gets choppy.

So I was thinking that guys here say don't get slow cards with too much memory(eg. a Geforce 210 with 1 GB or a GTS450 with 4 GB). Is this because of the memory bit width? The guy on newegg says it doesn't use the last 512MB as it only has a 192bit bus and 3 memory controllers, and the last controller has 1 GB memory on it instead of 512MB.

 

[JimF_35]

I hardly look at memory any more. The memory is the Frame Buffer that buffers the data that is being worked on. Different cards are going to use the memory differently so the sales person could be correct in that a 660 can't use all of the buffer depending on which resolution you are using. I think the last 512 M is usable by the 660 just at a slower rate.

This might help.

http://www.anandtech.com/show/6159/the-geforce-gtx-660-ti-review/2
http://www.youtube.com/watch?v=q0VNiWtQqb4

 

[unknownofprob]

the memory bus does a bit but not a lot, firstly, It depends on the GPU, the Vram doesn't barely help your game performance but multiple monitors (3GB-4GB-6GB), not saying Vram isn't needed at all because it is, just not when you have a single display with over 2GB (depends on the game also). These GPU's will only use all it's vram if it needs to, this means multiple monitors or high resolutions, but with low/mid end GPU's, the core itself will be struggling if you even get to using the extra Vram in the extra dedicated Vram models. So it will use most of it's vram under the right circumstances, otherwise your looking at a pointless card. For example; You need to see if it is DDR3 or GDDR5, there are huge differences between the memory speed, but there is no comparison between a GT 610 4GB DDR3 and a GTX 660 2GB as the core and Vram itself is completely different. the more Vram you have, the only difference it will make is if your GPU can handle the game in the first place, which if it is a low/mid end GPU trying to power multi screens/high resolutions these Vram figures are meaningless.