SLI working well!

[TomWelsh]

As I have spent the past week or so obsessing over the idea of dual GTX 1080 Ti's and finding at best mixed results, generally leaning heavily towards "SLI is redundant", I then bought a second one on eBay anyway as I'm stubborn. Since I've spent all this time wondering what the outcome would be in March 2019, I figured I'd report back my brief findings for anyone else wondering the same as me. 

 

Now, I've only installed the second card this evening and opened up every game I have installed for 10-20 minutes each while watching the GPU usage shown by Nvidia Profile Inspector and glancing over the FPS. This is far from scientific as I'm watching it in real time and can't remember what the FPS was like before hand with most games, but going of the GPU usage, which in theory should be demonstrating the scaling (which offcourse may not translate to actually performance increases in FPS). I'm certain that something will go wrong at some point, I just wanted to get an idea of what works and what doesn't. Aside from future games, my main concern was Kingdom Come (as it's a power hungry little bugger) and Total War, which although FPS is less important to me in that, there can be alot going on at once with 8000+ small people being animated in one field!

 

Anywho, the only game I've tried which hasn't scaled was Resident Evil 2, I did try a little tweak from reading about others getting it to work, but for me, 1 GPU sat around 1-3% usage while the other did all of the work. This does not bother me however as with every setting on max and 4K resolution, I was still hitting around 60 FPS at 55% usage- I am however in the sewer so that is probably a damn sight less demanding than other areas. 

 

Here are the GPU usage percentages from my short trial, these are where my usages settled while running around each game, some more precise than others.

Dying Light: 70-80% both cards

Rainbow Six Siege: 75% both cards 

Witcher 3: 100% both cards (although I'm sure they should only hit 99%?).

Ghost Recon Wildlands: 80-99% both cards (Temporal AA seemed best for performance and seemed to stop a small amount of flickering that appeared when I put everything on Max).

Total War Warhammer 1 & 2:  99% both cards during a custom battle. I did a very small tweak to one or two options in the Profile Inspector

Dark Souls 3: 60% ish both cards

Total War Shogun 2: 80-90% both cards

Metro Last Light Redux: 99% both cards. Also a small tweak to Profile Inspector options (Still needed to turn SSAA down from full which is just silly for dual 11GB cards...).

Kingdom Come Deliverance: around 99% both cards- Also cannot run on Ultra at 4K, I've got mine on Very high and that sits stable around 30-36 fps, not much better than it was before using a mixture of high settings but feels more consistent- another game renown for bad optimising.

 

PC running it:

Motherboard: MSI Z370 Pro Carbon Gaming (only supports x8/x8 SLI)

CPU: i7-8086k at 5Ghz

CPU Cooler: NZXT Kraken x52 water cooler

GPU: GTX 1080 Ti SLI (both blower cards)

RAM: 32GB Corsair Dominator Platinum 3000Mhz

PSU: EVGA 850w (I forget the model)

A Samsung 860 SSD for windows and cheap HDD's for everything else all inside a bloody big glass box. 

 

I highly doubt all of those 99% are actually doubling average or minimum frame rate, but it definitely looks promising! 

 

I'm not suggesting that anyone should bother with or avoid SLI, I am hoping that it will continue to work with Metro Exodus when I buy it and ideally Cyber Punk, but who knows, everyone seems to get varied results. But just trying to give some more up to date information on it. I am running all of these games at 4K (hints why I wanted a second card). Feel free to explain to me if my understanding of GPU usage is incorrect, but after thinking I've been a complete tit all day buying an expensive card, I'm pleasantly surprised to find out nearly everything I have works well. The lowest results are generally on games which were already flawless with settings maxed. 

 

I shall now await the abuse for suggesting that two GPU's might actually work some of the time.... 

[Enderman]

The percent usage on a GPU has nothing to do with how well SLI is scaling the fps.

 

That's like saying that a higher water bill for your house means your little brother is washing his hands more often.

[Jurrunio]

sometimes bad SLI scaling can be two cards spending a lot of time doing unnecessary stuff, so reading usage is meaningless.

[r2724r16]

27 minutes ago, TomWelsh said:

<wall of text>

Thank you Kayne, very cool! Also, this should be a status update.

[SenKa]

You know, I normally don't understand people who post these as threads. But SLI working well on DX12 is news to me.

[Mick Naughty]

Sli always works well if the game isn’t crap. You running into cpu usage issues? My 8700k can’t do it on any game. 

[TomWelsh]

Ah, well I did think it was too good to be true, I am seeing FPS increases though in most games, obviously not double (although Kingdom come did almost that before I upped the settings). I'd heard others say that often both cards would only run at half usage and be pointless, so figured it showed at least the games recognised the 2nd card? Nothing ran badly, even resident evil 2 seemed to just ignore and not have a negative effect if that's normal? 

 

Worth noting I believe every game was using DX11 as I'd heard of issues with 12 and since I don't really know what I'm doing I left it alone for now.  

 

CPU seemed fine, I was watching the temperature for that but not really paying much attention to the rest. 

 

Either way, I'm happy with them working, so thought SLI could do with some positivity. 

[TomWelsh]

Oh, and if I've posted it in the wrong category, my apologies. I don't use any forums so not a clue what should go where.