Upgrading GPU Confusions

[TheOrune]

Hey guys,

I wanted to ask if it would be a good idea to upgrade a single EVGA 970 SC to a two way SLI, in the light of Windows 10 and DX12 ( which can enable the doubling instead of mirroring the VRAM from 3.5gb to 7gb)? I'm all about future proofing my rig and i just got a 32" 1440p monitor and want to continue gaming AAA titles on ultra ....... and I'm all about dose numbas   (sorry).

If a similar post exists please link me to it because I couldn't find it.

[Arty]

Hey guys,

I wanted to ask if it would be a good idea to upgrade a single EVGA 970 SC to a two way SLI, in the light of Windows 10 and DX12 ( which can enable the doubling instead of mirroring the VRAM from 3.5gb to 7gb)? I'm all about future proofing my rig and i just got a 32" 1440p monitor and want to continue gaming AAA titles on ultra ....... and I'm all about dose numbas   (sorry).

If a similar post exists please link me to it because I couldn't find it.

You Shall Be Fine, Ethier Way

and it would be 6gbs of vram not 7

[TheOrune]

You Shall Be Fine, Ethier Way

and it would be 6gbs of vram not 7

If the 3.5gb came together wouldn't it be 7gb or is the problem because the last gb it split into parts?

I have an opening for a 970 on the cheap that's why I'm considering.

.....Sorry about the apparent lack of knowledge... still learning.

[Arty]

If the 3.5gb came together wouldn't it be 7gb or is the problem because the last gb it split into parts?

I have an opening for a 970 on the cheap that's why I'm considering.

.....Sorry about the apparent lack of knowledge... still learning.

You DiDn't know about that whole last .5 gb being slow Scandal Thing?

so yes its 7 but after 6gbs of usage (which You will Never hit unless you like dual 4k) it will slow down

[TheOrune]

You DiDn't know about that whole last .5 gb being slow Scandal Thing?

so yes its 7 but after 6gbs of usage (which You will Never hit unless you like dual 4k) it will slow down

But wasn't the scandal about .5gb of the original 4gb being waaay slower than the "primary" 3.5gb? 

[ThE_MarD]

Heyyo,

 

 

You DiDn't know about that whole last .5 gb being slow Scandal Thing?

so yes its 7 but after 6gbs of usage (which You will Never hit unless you like dual 4k) it will slow down

.... math ftw, lol.

 

GTX 970 = 3.5GB + 0.5GB...

 

3.5 x 2 = 7GB of faster access VRAM....

0.5 x 2 = 1GB slower access VRAM

 

7GB fast.. the last 1GB slow... so 8GB total.

 

Where'd you get 6GB from? lol.

[Arty]

Heyyo,

 

 

.... math ftw, lol.

 

GTX 970 = 3.5GB + 0.5GB...

 

3.5 x 2 = 7GB of faster access VRAM....

5 x 2 = 1GB slower access VRAM

 

7GB fast.. the last 1GB slow... so 8GB total.

 

Where'd you get 6GB from? lol.

i thought 970's came with 3.5gbs of ram not 4 lol

[TheOrune]

@The_MarD do you consider the VRAM merging in Windows 10 and DX12 is an actual possibility?

[Najuno]

i thought 970's came with 3.5gbs of ram not 4 lol

But it´s always important to tell people how scandalous all that is but you don´t even know the facts...

 

The GTX970 2way SLI is fine for 1440p. A friend of mine has a 1080p Surround and that´s more pixels to drive than 1 single 1440p monitor. No problems and all games maxed out unless we talk about a shitty game code like WatchDogs or AC:U.

[D2ultima]

Summarization:

Yes it'd be 7GB of fast memory

Yes it'd work fine

No it shouldn't be a problem

Please remember that non-DX12 games will still mirror vRAM

Please note that windows vRAM usage functions is currently unknown. If Windows requires 800MB (I've seen Windows 8.1 do this) it's possible it will do this mirrored across cards, and the vRAM adding will only count for the "free" memory available to the game itself. There's a lot of variables and different ways this can take place; including a DX12 backbone meaning that vRAM required by windows is in fact split across cards instead of copied; thus lowering Windows' memory footprint, etc. We can't say exactly what will be like until we use a lot of windows 10 and people who delve into the nitty gritty about usage/etc (like I do) figure out what's really going on. 

[ThE_MarD]

Heyyo,

@The_MarD do you consider the VRAM merging in Windows 10 and DX12 is an actual possibility?

Indeed! It's totally possible! The limitation right meow is DirectX 11 and down. Those were built for compatibility so they had no control over the frame buffer memory mapping. Mantle and DirectX 12 solve that issue by allowing better cross-communication between the GPUs. DirectX 12 I'm hoping is everything Microsoft says it is... I still remember being so pumped up about DirectX 10... and then the performance "gains" ended up not being true... so... fuck. lol.

NVIDIA has been touting NVLINK as the next evolution in that step... with direct communication lanes between the GPUs and CPU without the bandwidth limitations of PCI-E. AMD's XDMA is an example of this as we've seen the elimination of the CrossFire bridge on the R9 290 series... BUT, that's only cross-communication between GPUs... will they add the CPU into that mix? I guess we'll have to wait and see.

This is exactly why I'm holding onto my Two-Way GTX 680 setup until NVIDIA unleashes the magic that is NVIDIA's Pascal GPUs onto the market... Imagine the efficiency of current Maxwell cards with more memory and more bandwith... no bottlenecks between the GPU and CPU (constant battle of Multi-GPU systems btw)... wow... 4K @ 144Hz!? Potentially...

 

i thought 970's came with 3.5gbs of ram not 4 lol

Lol no worries. I gave your post a like cause it made me chuckle a little.

 

Summarization:

Yes it'd be 7GB of fast memory

Yes it'd work fine

No it shouldn't be a problem

Please remember that non-DX12 games will still mirror vRAM

Please note that windows vRAM usage functions is currently unknown. If Windows requires 800MB (I've seen Windows 8.1 do this) it's possible it will do this mirrored across cards, and the vRAM adding will only count for the "free" memory available to the game itself. There's a lot of variables and different ways this can take place; including a DX12 backbone meaning that vRAM required by windows is in fact split across cards instead of copied; thus lowering Windows' memory footprint, etc. We can't say exactly what will be like until we use a lot of windows 10 and people who delve into the nitty gritty about usage/etc (like I do) figure out what's really going on.

I agree D2ultima, but for Windows requriing 800MB of VRAM? That's only when not in true fullscreen modes such as Windowed or Borderless Windowed. In those modes? It's rendering the Windows Explorer/Desktop. This is why NVIDIA SLI and AMD CrossFire do not work unless the game is true fullscreen. Look at The Elder Scrolls Online... CF and SLI didn't work for the longest time until Bethesda finally added a true fullscreen mode as the GPUs were constantly trying to do alternate-frame rendering yet Windows Explorer was all "fuck you render me too" and the first GPU was always stuck re-rendering the desktop constantly.

I can run more tests at home with Windows 10 Technical Preview build 9926 (tbh it's the only version of Windows installed on my PC Gaming rig lol) and see what MSI Afterburner spews out if for example I played a 2D game in true fullscreen and see if my memory useage does stay at a minimum of 800MB or so as you've said Windows 8.1 can use (I dunno, I just stuck with Windows 7 since Windows 8/8.1 never had any performance gains for gamers tbh). It's the same thing as seen when playing a 3D game in true fullscreen and alt-tabbing to the desktop. The GPUs will go into idle mode and drop their usage to low values.

[D2ultima]

I agree D2ultima, but for Windows requriing 800MB of VRAM? That's only when not in true fullscreen modes such as Windowed or Borderless Windowed. In those modes? It's rendering the Windows Explorer/Desktop. This is why NVIDIA SLI and AMD CrossFire do not work unless the game is true fullscreen. Look at The Elder Scrolls Online... CF and SLI didn't work for the longest time until Bethesda finally added a true fullscreen mode

Windows 8 requires 256MB minimum and more if having second monitors attached.

nVidia SLI works in any rendering mode. Crossfire is the only option which requires fullscreen.

This is a piece of crap coded by people who can't even find a way to make their games alt-tab without crashing or introducing bugs when modders without mod tools can fix that in a week of launch. That is the ONLY game I am aware of which uses SLI in fullscreen and not in windowed mode or borderless windowed.

 

Anything else I can prove for you?

[ThE_MarD]

Heyyo,

Windows 8 requires 256MB minimum and more if having second monitors attached.

nVidia SLI works in any rendering mode. Crossfire is the only option which requires fullscreen.

This is a piece of crap coded by people who can't even find a way to make their games alt-tab without crashing or introducing bugs when modders without mod tools can fix that in a week of launch. That is the ONLY game I am aware of which uses SLI in fullscreen and not in windowed mode or borderless windowed.

 

Anything else I can prove for you?

Interesting! I guess it does depend on the game's implementation of Multi-GPU for working in borderless windowed. I consider myself corrected. Maybe it is just ESO and a handful of other games that screw up in that sense and/or CrossFire.