SLI GTX 780ti vs SLI GTX 780 6GB

[Zettman]

First some information about my current setup:

 

CPU: i7-4820K

GPU: 2xGTX 670

Mainboard: GA-X79-UP4

RAM: 16 GB

PSU: 1200W

 

Monitors: 3x Asus VN279QLB (3400x1920 with bezel correction)

 

I want to upgrade my System with two new Graphiccards. I already tried 2xR9 290x but wasn't happy about several (not game related) issues, so I decided to stay with Nvidia.

 

My Question is if some one has a SLI GTX 780 ti setup and can tell me if he is running out of VRAM. I'm not sure if I should go for two GTX 780ti or two GTX 780 6GB. For most games 3GB of VRAM is more than enough and only raw GPU performence is important. But SLI (VRAM is mirrowed) and Triple Monitor Setup is something most internet reviews don't take into account. So I would like to know from someone with a similar setup what is limiting him (VRAM or raw GPU performence).

 

With best regards,

Zettman

 

[FuriousMeow]

SLI does not currently work with BoS. I was contacted by nVidia devs regarding their latest driver's and that it should support BoS with SLI but it does not. I have submitted a video to nVidia's team showing what happens when AFR2 is forced - AFR2 forced is the only way for SLI to work, but it has terrible texture flashing. AFR1 forced is awful performance and nVidia recommended doesn't work for SLI.

 

So don't go SLI for this title just yet. It'll be supported eventually, but it looks to be more of nVidia's side holding the reigns on that.

Edited August 24, 2014 by FuriousMeow

[1PL-Husar-1Esk]

 

 

AFR2 is forced - AFR2 forced is the only way for SLI to work

 

 

FuriousMeow How to force AFR2 with BOS? (i have GTX 590 and use Nvidia 3D vision and wanna check performance when SLI is active). Thanks

[1PL-Husar-1Esk]

OK i found that and force it. And yes there are some black flickering textures. 

[Zettman]

Are you guys sure that with Nvidia Surround enabled (3 Monitors) SLI isn't working by default? Atleast both of my old GTX670 are hitting 100% while playing IL2 BoS on three Monitors.

 

Zettman

[1PL-Husar-1Esk]

Not forcing BOS to use SLI, there are only activity on GPU 1. And when forcing SLI, I found that GPU2 is half used compared to GPU 1. One monitor 120Hz.

[Zettman]

So anyone who plays on 3 Monitors or has a very high resolution can tell me if VRAM is capping him? If I would play on one Monitor only one card and 3GB VRAM would be enough for sure, but Having 3 Monitors and a resolution of 3400x1920 makes me wonder if I would need more than 3GB of VRAM to run this game on highest settings in Nvidia Surround configuration.

 

Zettman

[CisTer-dB-]

Just 1 R9 295x2. Like that you have not to worries about SLI or crossfire support and config and that fucker outperform 2 x GTI780 with more memory, 8GB intead or 6GB and cheaper. 

Edited August 28, 2014 by Decibel_dB

[Zettman]

I wouldn't need to worry about Crossfire, that is right, but I would feel better with Nvidia Cards (the 100€ extra per card don't matter that much). I would really like to know how much VRAM this game needs at high resolutions/triple monitor. If it does not need the 3GB I would go with the GTX 780 Ti any time.

 

Edit: And aren't these just 2x4 GB VRAM on the R9295x2? I thing they are mirrored too, so you wont be able to use 8 GB but just 4 GB (not sure, have not that much experience with AMD/Radeon), with the GTX 780 6GB in SLI I would have 2x6GB VRAM. But yeah 4 GB of VRAM would still be enough.

 

And I just checked the prices, one R9 295x2 costs about 1100€, I can get two GTX 780 6GB for 1000€ (500 each) or two GTX 780 Ti for about 1060-1200€. So the diffrence is not that big.

 

Zettman

Edited August 28, 2014 by Zettman

[CisTer-dB-]

I`ve always been with NVIDIA and I was on the market for a new rig, I was recommended to have a look at it. I did  and with the numbers that was a no brainer for me. More pixel per dollar . That is the only single card that have enough horsepower to drive a 4K resolution which is close to what you have, not to mention that 2 GPU in SLI is never trouble free, some game are not ever supporting it. Google it and have a look for yourself you can ask some questions on the overclock forum http://www.overclock.net there is some very knowledgeable guys who can answer them

 

o7 

 

BTW the ram are not mirrored on the R9 295x2 you have the full 8 GB

Edited August 28, 2014 by Decibel_dB

[Zettman]

After asking some questions on overclock.net, they told me that the R9 295x2 is just like two R9 290x in CF. The VRAM is mirrored, so you will only have 4 GB and you still have all the troubles that come with CF. As this card holds no real advantage to me compared to two GTX 790 Ti, I will stick to Nvidia.

 

Zettman