Eyefinity vs Surround, And a new GPU?

[bystander]

Sorry, not exactly what i meant, I believe I am wrong. What I meant was that the GPUs work together. They do not render alternate screens like suggested(1 card works 2 screens and one card works one). This isnt correct. 2 2gb cards in SLI/CF would operate similarly to a 4gb card because they render only half the amount of frames, using half the amount of memory each. For example if a game uses 2gb, each GPU will probably use around 1gb. I am correct right?

You got that backwards, sort of.

Because each GPU renders alternating frames, they each must have all the same data loaded into their VRAM. They need a full frame buffer, as they are rendering a complete image, no matter how many screens it is being delivered to. The cards do not share any data between them. In this case (99.9% of the time now), there is nothing the 2nd cards VRAM brings to the table in terms of what their VRAM can do.

Back in the day, there were other methods of SLI/Crossfire, where one card would render half the screen, and the other card would work on the other half. In this case, both cards still need all the same textures and what not loaded, but they only had to have half a frame buffer, as they only rendered half the screen. In this case, the 2nd cards VRAM adds a little benefit beyond what it does for its own screen, but not today, not with AFR.

But what about in the case of the radeon 7990 and 690 that have one unified memory pool?

Seems you got caught with marketing mis-info.

The 7990 and 690 do not have unified memory, but they usually add up the VRAM in their marketing. However, a 7990 6GB behaves as two 7970 3GB Crossfire, and the 690 4GB behaves like 680 2GB SLI.

 

[kirilmatthew]

Sorry, not exactly what i meant, I believe I am wrong. What I meant was that the GPUs work together. They do not render alternate screens like suggested(1 card works 2 screens and one card works one). This isnt correct. 2 2gb cards in SLI/CF would operate similarly to a 4gb card because they render only half the amount of frames, using half the amount of memory each. For example if a game uses 2gb, each GPU will probably use around 1gb. I am correct right?

You got that backwards, sort of.

Because each GPU renders alternating frames, they each must have all the same data loaded into their VRAM. They need a full frame buffer, as they are rendering a complete image, no matter how many screens it is being delivered to. The cards do not share any data between them. In this case (99.9% of the time now), there is nothing the 2nd cards VRAM brings to the table in terms of what their VRAM can do.

Back in the day, there were other methods of SLI/Crossfire, where one card would render half the screen, and the other card would work on the other half. In this case, both cards still need all the same textures and what not loaded, but they only had to have half a frame buffer, as they only rendered half the screen. In this case, the 2nd cards VRAM adds a little benefit beyond what it does for its own screen, but not today, not with AFR.

But what about in the case of the radeon 7990 and 690 that have one unified memory pool?

Seems you got caught with marketing mis-info.

The 7990 and 690 do not have unified memory, but they usually add up the VRAM in their marketing. However, a 7990 6GB behaves as two 7970 3GB Crossfire, and the 690 4GB behaves like 680 2GB SLI.

So essentially each GPU takes half of the vram for itself, makes sense!

 

[cindylo]

Yea. Also when I meant is in SLI/CFX you normally plug 1 monitor into 1 card then 2 into the main. Or if you are running a triple SLI/CFX setup you just do 1 per card.

 

[bystander]

Yea. Also when I meant is in SLI/CFX you normally plug 1 monitor into 1 card then 2 into the main. Or if you are running a triple SLI/CFX setup you just do 1 per card.

That isn't possible with Crossfire. SLI allows you to do this, but Crossfire only lets you use the 1st card for monitors.

 

[kirilmatthew]

Yea. Also when I meant is in SLI/CFX you normally plug 1 monitor into 1 card then 2 into the main. Or if you are running a triple SLI/CFX setup you just do 1 per card.

Right, but the one you plug it in to doesn't affect which card is used to power the monitors. All GPUs are used to power all monitors.

 

[bystander]

Yea. Also when I meant is in SLI/CFX you normally plug 1 monitor into 1 card then 2 into the main. Or if you are running a triple SLI/CFX setup you just do 1 per card.

Right, but the one you plug it in to doesn't affect which card is used to power the monitors. All GPUs are used to power all monitors.

True, though with Crossfire, the top card is the only one that accepts monitors. The 2nd card gets treated as a slave, and even powers off when not used. It's more difficult to setup, though it does save power.

 

[kirilmatthew]

Yea. Also when I meant is in SLI/CFX you normally plug 1 monitor into 1 card then 2 into the main. Or if you are running a triple SLI/CFX setup you just do 1 per card.

Right, but the one you plug it in to doesn't affect which card is used to power the monitors. All GPUs are used to power all monitors.

True, though with Crossfire, the top card is the only one that accepts monitors. The 2nd card gets treated as a slave, and even powers off when not used. It's more difficult to setup, though it does save power.

Yeah, I'd rather take the power savings though, keeps everything cooler.

 

[cindylo]

I'll just take the GTX 660 then probably. Seems to be easier for SLI and such later down the road. I don't really care about saving power at the moment. I'm not going to be buying a new gaming GPU for its power saving features

 

[bystander]

I'll just take the GTX 660 then probably. Seems to be easier for SLI and such later down the road. I don't really care about saving power at the moment. I'm not going to be buying a new gaming GPU for its power saving features

Powerwise, Nvidia single cards save more already, for the most part. In multi-GPU setups, AMD's save a little during idle. While gaming it still favors Nvidia. That is with this generation, and when comparing similar cards.

 

[kirilmatthew]

I'll just take the GTX 660 then probably. Seems to be easier for SLI and such later down the road. I don't really care about saving power at the moment. I'm not going to be buying a new gaming GPU for its power saving features

Okay! Some games will not do as great because of the lower vram on surround but it should work decently, especially without AA.

 

[cindylo]

I will probably get the 3GB version of the 660 To prevent that issue.

 

[kirilmatthew]

I will probably get the 3GB version of the 660 To prevent that issue.

Good plan!

 

[bystander]

I doubt that will ever be the case, but it doesn't hurt to be prepared. It takes some insane settings to be able to use all the 2GB of Vram, and with a single 660, that is highly unlikely to be playable on 3 screens regardless of the vram.

 

[kirilmatthew]

I doubt that will ever be the case, but it doesn't hurt to be prepared. It takes some insane settings to be able to use all the 2GB of Vram, and with a single 660, that is highly unlikely to be playable on 3 screens regardless of the vram.

A single monitor 1080p maxed out on everything only uses 1-2Gb generally. For an SLI setup though, the 3Gb would help.

 

[cindylo]

Actually on some newer games with the settings maxed on 5670x1080 it will go to 2.5GB. That's not including AA which will take up another 1GB if cranked up all the way.

 

[kirilmatthew]

Actually on some newer games with the settings maxed on 5670x1080 it will go to 2.5GB. That's not including AA which will take up another 1GB if cranked up all the way.

For SLI 3Gb per card is what you need.

 

[bystander]

Actually on some newer games with the settings maxed on 5670x1080 it will go to 2.5GB. That's not including AA which will take up another 1GB if cranked up all the way.

On newer games, with everything maxed, a single 660 won't come anywhere close to playable, even with 6gb of vram.

Also, many of those newer games that may show up to 2.5gb used, are perfectly fine at 2gb. Just because they load that extra .5gb of stuff, doesn't mean it needs to be there. It is just a matter of preloading stuff if they can.

The only time I've seen reviews done that run into issues are with 690's, or 680 SLI, and they are running FPS that are marginal at best, even with the extra vram.

 

[kirilmatthew]

Actually on some newer games with the settings maxed on 5670x1080 it will go to 2.5GB. That's not including AA which will take up another 1GB if cranked up all the way.

On newer games, with everything maxed, a single 660 won't come anywhere close to playable, even with 6gb of vram.

Also, many of those newer games that may show up to 2.5gb used, are perfectly fine at 2gb. Just because they load that extra .5gb of stuff, doesn't mean it needs to be there. It is just a matter of preloading stuff if they can.

The only time I've seen reviews done that run into issues are with 690's, or 680 SLI, and they are running FPS that are marginal at best, even with the extra vram.

For a single one for sure 2Gb is fine. For SLI surround I would get 3Gb.

 

[bystander]

I won't argue that in SLI setups, you might want more vram, but people act like 2GB's isn't enough, when it is almost unheard of to actually cause a problem. You'll see reviews done using settings that drop FPS to less than 30, and show the 2gb card at 10 and say how it was limited by vram, when the settings used were unplayable regardless.

The extra vram is for those who want the security to know they won't run short of vram. It isn't really a requirement.

 

[cindylo]

I also plan to mod games(like skyirm and GTA4). ANd I know the more ram the better with those. Yes I know most the time the 660 won't have enough power to make the extra 1Gb matter but in the future it will and for SLI it will.

 

[bystander]

I also plan to mod games(like skyirm and GTA4). ANd I know the more ram the better with those. Yes I know most the time the 660 won't have enough power to make the extra 1Gb matter but in the future it will and for SLI it will.

SLI doesn't require extra VRAM (2Gb is enough, 99.9% of the time). The only reason people mention SLI, is it would take a ton of horsepower to get to a point that you could turn up settings enough to have any game ever hit the VRAM ceiling (not that you'd want to play at those settings).

That said, you plan to mod the heck out of Skyrim, you'll need more VRAM.

 

[cindylo]

Yea I know. For GTA 4 also. I know some of the really hirez textures packs for skyrim recommend 1gb+ vram. So I figure give it 3gb. For all 3 displays and the mods. GTA4 is also known to just eat vram as well. And I know the new games like BF4 and watch dogs are not going to be light either. Especially not when you start cranking up those details(want to have SLI by that time maybe). There are quite a few games that come to mind actually that could use 2gb+ of vram that are coming up.

 

[bystander]

Yea I know. For GTA 4 also. I know some of the really hirez textures packs for skyrim recommend 1gb+ vram. So I figure give it 3gb. For all 3 displays and the mods. GTA4 is also known to just eat vram as well. And I know the new games like BF4 and watch dogs are not going to be light either. Especially not when you start cranking up those details(want to have SLI by that time maybe). There are quite a few games that come to mind actually that could use 2gb+ of vram that are coming up.

From the benchmarks I've seen of the BF4 alpha/beta, it will not require more than 2GB. They rain 5760x1080 just fine with 2gb. Mods are about the only way people run into issues with playable FPS. You plan to mod, so go for 4GB, I'm just trying to make it clear that currently, and the near future, 2GB is fine. People make way to much noise about this after reading a review with 680/770 SLI using the most ultimate settings, and getting less than 30 FPS, even on 7970 Crossfire (which as 3Gb). Generally speaking, to push higher Vram limits, you usually have to have more horsepower than the cards have currently.

 

[cindylo]

Actually you are wrong there. I mean yes the BF4 alpha bench was optimized but its still something interesting to see. http://puu.sh/49HrA.jpg
Its also may have just been barely hitting 2GB on some of those resolutions, but its never a good idea to have the exact amount for vram. Because if its hits the ceiling er geta within a few mb your FPS will drop like a rock. I know it will go down but still. For triple monitor games (newer) and modding games you will need and use the 3-4GB. People were saying 3 yrs ago that you would never need more than 1GB of vram for games. And look at how much they use now. Crysis 2-3 will use 2.5+ so will BF3,skyrim and also a few others.

 

[bystander]

Again, you are assuming because it shows it uses more than 2GB, it needs more than 2GB. Preloading of textures takes extra memory, but preloading of textures isn't needed.

Take a look at the page you got your link from. This is with the same settings as the graph you showed: http://www.bf4blog.com/battlefield-4-alpha-gpu-and-cpu-benchmarks/

You should notice a couple things here:
1) The 2gb 680 and 3g 7970 perform similarly, minimums and average are actually higher on the 680 2gb. Even when you go up to the 690 and 7990.
2) You'll notice that the settings used to hit those numbers were unplayable already, meaning, as you turn down settings, you'll need even less vram.