Quad Sli / Quad CrossfireX

[Morris123]

Hi,

It might be me, but i seem to have the greatest trouble finding a list of all the graphics cards capable of Quad Sli or Quad CrossfireX. I have tried googling all sorts of search terms to no avail. Perhaps some of you guys here know of such a list? Thanks in advance,

Morris

 

[4745454b]

They would be the "x2" GPUs. Any of the video cards with two GPUs on it. 6990, 7990, 295, etc.

 

[Egitel]

They would be the "x2" GPUs. Any of the video cards with two GPUs on it. 6990, 7990, 295, etc.

What he said. 4-way SLI = 4 separate cards in SLI. Quad SLI = 2 cards, 2 GPUs per card.

 

[4745454b]

Can you SLI 4 separate cards? I thought there weren't enough connectors to do that? (SLI bridges or whatever you call them.)

 

[Egitel]

Yep! http://www.blogcdn.com/www.engadget.com/media/2010/04/4-25-10-4804waysli.jpg

Nvidia doesn't officially support it, from what I understand, though (not sure about ATI). There's some stability problems apparently, but some people do it for benchmarking purposes and because they apparently have a lot more money to throw around than I do.

 

[Morris123]

Yeah, what i was talking about here would indeed be 4 separate cards. I recently purchased a 4k monitor running at 60 fps. Only the most expensive cards would be enough when i use 2 cards. Thats why i'm looking at cheaper/older cards capable of Quad setup. I could possibly purchase these second hand which would save lots of money. And my motherboard is capable of handling quad setups.

Morris

 

[Egitel]

Well the biggest issue is that resolution is going to be memory intensive, and memory doesn't stack in any SLI set up, so unfortunately I think the only viable options are going to be the newer more expensive options, since older cards aren't going to have the VRAM to support 4k. :l

 

[Morris123]

Well the biggest issue is that resolution is going to be memory intensive, and memory doesn't stack in any SLI set up, so unfortunately I think the only viable options are going to be the newer more expensive options, since older cards aren't going to have the VRAM to support 4k. :l

Thnx for this info, i will look into this. I have 2 7850 in crossfire now and their gpu load is at 100% all the time while running a game.

 

[Egitel]

Well the biggest issue is that resolution is going to be memory intensive, and memory doesn't stack in any SLI set up, so unfortunately I think the only viable options are going to be the newer more expensive options, since older cards aren't going to have the VRAM to support 4k. :l

Thnx for this info, i will look into this. I have 2 7850 in crossfire now and their gpu load is at 100% all the time while running a game.

Ah, yeah. I think 4k really likes having 3 GB or even 4 GB of VRAM. The downside about VRAM not stacking, too, is that Nvidia and ATI use a bit of false advertising with this, too. They'll say a dual GPU card for example has 12 GB of VRAM, when it really might "only" be 6 GB effective, because it's 6 GB per card, but the memory doesn't actually stack. So they're just referring to the physical amount of memory total on the card, even though it's only making use of half of it.

 

[Morris123]

Well the biggest issue is that resolution is going to be memory intensive, and memory doesn't stack in any SLI set up, so unfortunately I think the only viable options are going to be the newer more expensive options, since older cards aren't going to have the VRAM to support 4k. :l

Thnx for this info, i will look into this. I have 2 7850 in crossfire now and their gpu load is at 100% all the time while running a game.

Ah, yeah. I think 4k really likes having 3 GB or even 4 GB of VRAM. The downside about VRAM not stacking, too, is that Nvidia and ATI use a bit of false advertising with this, too. They'll say a dual GPU card for example has 12 GB of VRAM, when it really might "only" be 6 GB effective, because it's 6 GB per card, but the memory doesn't actually stack. So they're just referring to the physical amount of memory total on the card, even though it's only making use of half of it.

This is interesting. Are you saying the VRAM never stacks on multi GPU cards or setups? or on most of them?

 

[Egitel]

This is interesting. Are you saying the VRAM never stacks on multi GPU cards or setups? or on most of them?

Never stacks. CUDA cores, and things like that stack, VRAM doesn't. Basically uhh.. has something to do with how SLI/Crossfire work, like.. each GPU renders a frame, so if you've got 2-way SLI, one GPU renders one frame, the other GPU renders the next, and each GPU can only make use of its own VRAM in order to do this. That's also why VRAM must be equal across all the cards, so even though you can use say an MSI GTX 770 in SLI with an ASUS 770, they both have to be either the 2 GB or the 4 GB version, you can't have one 2 GB and one 4 GB.

 

[Morris123]

This is interesting. Are you saying the VRAM never stacks on multi GPU cards or setups? or on most of them?

Never stacks. CUDA cores, and things like that stack, VRAM doesn't. Basically uhh.. has something to do with how SLI/Crossfire work, like.. each GPU renders a frame, so if you've got 2-way SLI, one GPU renders one frame, the other GPU renders the next, and each GPU can only make use of its own VRAM in order to do this. That's also why VRAM must be equal across all the cards, so even though you can use say an MSI GTX 770 in SLI with an ASUS 770, they both have to be either the 2 GB or the 4 GB version, you can't have one 2 GB and one 4 GB.

Thanks, i think this solves the problem. No quad setup for me. I'll start looking for a better single or dual setup.

 

[4745454b]

Ah, forgot about those dual connectors. I'll try to remember. I know AMD is much more forgiving in their setups allowing tri fire. Unless they have changed their stance Nvidia doesn't allow that.

Good info for the OP. If a 7850 CF setup is still hitting 100% load you'll want the 280X at least. 280 maybe.

 

[Egitel]

This is interesting. Are you saying the VRAM never stacks on multi GPU cards or setups? or on most of them?

Never stacks. CUDA cores, and things like that stack, VRAM doesn't. Basically uhh.. has something to do with how SLI/Crossfire work, like.. each GPU renders a frame, so if you've got 2-way SLI, one GPU renders one frame, the other GPU renders the next, and each GPU can only make use of its own VRAM in order to do this. That's also why VRAM must be equal across all the cards, so even though you can use say an MSI GTX 770 in SLI with an ASUS 770, they both have to be either the 2 GB or the 4 GB version, you can't have one 2 GB and one 4 GB.

Thanks, i think this solves the problem. No quad setup for me. I'll start looking for a better single or dual setup.

Honestly that's the best way to do it. Most powerful single card you can afford, and then SLI/Crossfire down the road in lieu of upgrading.

 

[Morris123]

Thanks for the info guys, I think ill be going for the 290X

 

[Egitel]

Thanks for the info guys, I think ill be going for the 290X

Oooh, yep. I've heard good things about that one in 4k. I'm an Nvidia man currently myself so I don't know first-hand, haven't had an ATI since the 5770 was semi-new, but seen plenty of solid benchmarks for the 290x.