2x VRAM on SLI Not fake?

[stavrosmast]

So, I have read on thousands of forums that when you SLI 2 cards you dont get double performance but in numerous vids on youtube with SLI configs playing gta in the graphics menu it says the double memory not just the one's card. How is this possible?

Example:http://i.imgur.com/HS4mENi.png

 

[stavrosmast]

* https://www.youtube.com/watch?v=Hw9KSuEhfzE

 

[bgunner]

You do not get double teh performance, this is true. you get around 50% more performance.

Yes you do get double the VRam this is because each card has there own Ram and soem programs read it as all in 1 and not separated.

THe performance not being doubled have very little to do with the VRam amount.

 

[stavrosmast]

I mean that its possible to use settings which use 7,9gb and the frames look like every card had 8gb?

 

[RCFProd]

GTA V shows it incorrectly, and that is known. VRAM does not stack.

And other specs matter than just 8GB VRAM. If you have an R9 390 8GB, it does not mean settings with over 6+ GB will run all that smoothly with 60 fps and all that.

 

[stavrosmast]

Yes i know that about 390 but he doesnt have bad fps so his ram is stacked rihgt?

 

[RCFProd]

Yes i know that about 390 but he doesnt have bad fps so his ram is stacked rihgt?

No, the higher VRAM usage in games than the amount of VRAM available does not mean bad fps. You can have a GTX 960 2GB use 2.5GB of memory and still sit at 60 fps consistently.

Anyways there is no application that shows the VRAM usage accurately. We don't know how much VRAM is ever used I think.

 

[bgunner]

Yes i know that about 390 but he doesnt have bad fps so his ram is stacked rihgt?

No, the higher VRAM usage in games than the amount of VRAM available does not mean bad fps. You can have a GTX 960 2GB use 2.5GB of memory and still sit at 60 fps consistently.

Anyways there is no application that shows the VRAM usage accurately. We don't know how much VRAM is ever used I think.

MSI Afterburner does a good job of showing the Vram usage of cards. and is able to be displayed on screen in DX games.

 

[sizzling]

You do not get double teh performance, this is true. you get around 50% more performance.

Yes you do get double the VRam this is because each card has there own Ram and soem programs read it as all in 1 and not separated.

THe performance not being doubled have very little to do with the VRam amount.

What? You don't get double the performance but its usually much more of an increase than 50%, it can be up to 90% depending on game and driver. Also vram never doubles, it is claimed it might when games start using DX12 but at the moment vram does not add, both cards store the exact same information and can't see the data stored in the vram of the other card

 

[bgunner]

you get double the Vram but it is not counted as doubled because each card has a process sent to it and it uses it's own ram. I did not say it stacks. I said you get double the ram that some games read as all in 1.

As for performance the worst games coded for SLI/Crossfire get only 50 % and never 100%. You even said this. So performance is not doubled.

THe way most sli setups work is on card works on one frame while the other card works on the next. Each card uses it's own ram and that ram is never shared between the cards, at this point.

Yes I do know what I am talking about but you just didn't under stand what I was trying to say.

 

[RCFProd]

They say even MSI Afterburner does not read VRAM usage correctly. There was an argument on it recently.

 

[bgunner]

They say even MSI Afterburner does not read VRAM usage correctly. There was an argument on it recently.

because the VRam usage is always changing so much depending on where your looking and what happens in the Frame I can see where it is hard to accurately state the exact amount used but when you have 4GB of ram and the game uses around 2.4 to 2.7GB is it really all that important to have the exact number down to the exact MB? 100-200MB difference will usually not effect you that much unless the game needs more than what your card/cards have.

 

[sizzling]

you get double the Vram but it is not counted as doubled because each card has a process sent to it and it uses it's own ram. I did not say it stacks. I said you get double the ram that some games read as all in 1.

As for performance the worst games coded for SLI/Crossfire get only 50 % and never 100%. You even said this. So performance is not doubled.

THe way most sli setups work is on card works on one frame while the other card works on the next. Each card uses it's own ram and that ram is never shared between the cards, at this point.

Yes I do know what I am talking about but you just didn't under stand what I was trying to say.

I'm sorry but that means your earlier post is so poorly written it contradicts what you are now saying. You said "you get around 50% more performance" which is wrong, the average must be around 70% - 80% when sli is supported, you also said "Yes you do get double the VRam this is because each card has there own Ram and soem programs read it as all in 1 and not separated." which is just wrong

 

[bgunner]

you get double the Vram but it is not counted as doubled because each card has a process sent to it and it uses it's own ram. I did not say it stacks. I said you get double the ram that some games read as all in 1.

As for performance the worst games coded for SLI/Crossfire get only 50 % and never 100%. You even said this. So performance is not doubled.

THe way most sli setups work is on card works on one frame while the other card works on the next. Each card uses it's own ram and that ram is never shared between the cards, at this point.

Yes I do know what I am talking about but you just didn't under stand what I was trying to say.

I'm sorry but that means your earlier post is so poorly written it contradicts what you are now saying. You said "you get around 50% more performance" which is wrong, the average must be around 70% - 80% when sli is supported, you also said "Yes you do get double the VRam this is because each card has there own Ram and soem programs read it as all in 1 and not separated." which is just wrong

And conversation over, the only thing you have done is come into this post and criticize and not add to better the thread.

Yes at time I do poorly write posts. But hear is some 1st grader math for ya, 3+3=6. Not how it is used, but 2 cards with 3 GB of ram equals 6 GB total but because it only get used on there cards its self and not STACKED the usable total is 3 for the game. Have a good time criticizing the next person with a disability pal.

 

[sizzling]

you get double the Vram but it is not counted as doubled because each card has a process sent to it and it uses it's own ram. I did not say it stacks. I said you get double the ram that some games read as all in 1.

As for performance the worst games coded for SLI/Crossfire get only 50 % and never 100%. You even said this. So performance is not doubled.

THe way most sli setups work is on card works on one frame while the other card works on the next. Each card uses it's own ram and that ram is never shared between the cards, at this point.

Yes I do know what I am talking about but you just didn't under stand what I was trying to say.

I'm sorry but that means your earlier post is so poorly written it contradicts what you are now saying. You said "you get around 50% more performance" which is wrong, the average must be around 70% - 80% when sli is supported, you also said "Yes you do get double the VRam this is because each card has there own Ram and soem programs read it as all in 1 and not separated." which is just wrong

And conversation over, the only thing you have done is come into this post and criticize and not add to better the thread.

Yes at time I do poorly write posts. But hear is some 1st grader math for ya, 3+3=6. Not how it is used, but 2 cards with 3 GB of ram equals 6 GB total but because it only get used on there cards its self and not STACKED the usable total is 3 for the game. Have a good time criticizing the next person with a disability pal.

Well actually I helped more than you, I at least stopped the OP going away with the wrong understanding.

As for the second part of your statement, well what a childish load of waffle which you know is not what the OP was asking about and is a poor attempt to salvage something from your first post. You would have been better off just saying you made a mistake, we all do that from time to time.

 

[stavrosmast]

Lets dont turn this into a fight just discussion. Yes I was writing a bit fast I meant double VRAM. Ok I got it it doesnt get doubled stop arguing