So far about several months about, I decided to do something I have never done before with nvidia cards. I have done tri-way xfire with ati cards years back but never more then 2 cards with nvidia. My first hand experience with 4-Way Sli is better then I originally expected. Cards used: 4 Gtx 970 Windforce(Gigabyte) I can not stress this enough, The heat will be your primary issue here if its not watercooled, I was looking into the kraken aio but cost is to much for an old card so I decided to stick with the stock heatsink, price of the kraken is like the price of a good used gtx 970, absolutely not worth it so I passed. used Thermal Grizzly Kyronaut paste, Upgraded thermal pads. I have one 140mm fan on the left most of the card helping cooling the VRM's, other 120mm(110cfm) fan blowing from the right side of the cards, and a table fan blowing into the case. I get about 70 to low 80C on all first 3 cards, the last about is in the 60 C. I strongly recommend doing this outside the case but I didn't feel like taking everything part and doing it outside so I increased the cooling by putting fans,etc.(UPDATE: CHANGED to 4 110cfm+ fans in front, 2 fans on side of the Gpu's for extra cooling +Spacers.) Working from 2-way sli to 4-way, Is no joke, hardcore tuning both bits and in-game settings is a MUST. All these were tested at 4k(2400p): GAMES NOT LISTED HERE TO DUE THE AMOUNT OF SPACE I CAN TYPE, SO CHECK OTHER PAGES, THANKS. GHOST RECON: WILDLANDS(DECENT TO GOOD SCALING/SOME FLICKERING INVOLVED - SEE PG. 5 - FINAL - (7/23/19). DRAGON QUEST XI: Decent - (UPDATED ON 6/21/19) - (CHECK PG. 5 for updates) GHOST OF A TALE: Decent 3DMARK-FIRESTRIKE ULTRA: So So HEAVY RAIN: Tuning Sensitivity = WORST(game on hold). STAR WARS BATTLEFRONT(2015): Decent A PLAGUE TALE: INNOCENCE: Very good Scaling/Some Flickering - (See pg. 4 for rundown) BF 1: Eh to Decent(Depending on what you are doing in the game) COD - GHOST: Not really, have to use Nvidia inspector SGSSAA Injection to make better scaling, even then, eh. CRYSIS 2 + MALDO MOD: Excellent - Check page 4. CRYSIS 3: Decent to Very good ECHO: Very good/Excellent Scaling(Pg. 13-16 for rundown) WITCHER 3: Scaling seems Great but tons of graphic flickering, and a whole bunch of other things, as of right now, only 2 way as of now. UNIGINE: SUPERPOSITION: Beautiful Scaling! DARK SOULS 2(DX9 API): Since the game is capped at 60 fps, I had to use 8xMsaa +8xSGSSAA to further stress the card down to its knees and make scaling much better, I would say not really, there is certain parts like if your viewing the waterfall in the beginning, it drops down to 15 fps per card, but soon as I use 4, I get 60 fps, so scaling is good depending on what your looking at, but the game overall while playing, I get constant 60 fps with basically 3-way like scaling. YAKUZA KIWAMI 2 - EXCELLENT(Except for Scaling drag issues(certain Spots) during 3-way and 4-way Sli/Check pg. 10-13. BATTLETECH(Updated - 7/29/19 - Lots to cover - check pg. 6-7) DYING LIGHT: Very good scaling, only problem is the blood splatter on the screen flickers alot, other then that, great scaling. REMNANT: BEYOND THE ASHES: Despite differences from 3 gpu's to 4 gpu's, 4 gpu performance is like 3 gpu's, check pg 8. KINGDOM COME: DELIVERANCE (5/16/19): Check pg. 4 for final rundown - FINAL - FFXII - THE ZODIAC AGE(WITH 60FPS CAPPED REMOVED): EXCELLENT SCALING!!! and best of all Absolutely no flickering, no hitchin, hang, nothing, absolutely perfect, only one drawback if the fps cap is removed, the game moves incredibly fast, like in fast motion. GRID AUTOSPORT - Have to use Sparsegrid injection otherwise the scaling is to weak, and the scaling after Sgssaa, I would say eh to so so.. LOST PLANET 1 - (DX10 API): Game is capped at 120 fps, so I had to use Sparsegrid aa to further push the cards down since without sgssaa, the card is using like 60% usage or so and caps at 120 fps, after testing with 8xMsaa + 8xSgssaa = Great scaling. DEUS EX - MANKIND DIVIDED: Overall prettie good scaling, certain things have to be shut off, Like Taa cause the edges of buildings,etc creates annoying haze like over it, best to turn it off, certain settings needs to be toned down a bit otherwise you will have problems, like motion blur and texture set to high. DISHONERED 2: Decent but certain things needs to be toned down due to 3.5-4gb vram on the video card or it can be other certain settings that could cause the 4-way sli to react abnormal). GREEDFALL: WORK IN PROGRESS(CHECK PG 19.) MASS EFFECT ANDROMEDA: If your in buildings,etc it acts like 3 way, but when your outside, decent scaling, inside areas NAH. (UPDATE ON 1/2/20, RE-TUNING GAME/WORK IN PROGRESS,CHECK PG 19). MASS EFFECT 1: Used Texture mods and modified .ini file. Have to use Nvidia Inspector AA injection to further stress the cards down a bit to see good use of scaling, overall scaling good, mainly the only problem of hitching is in Presidum, But I have found a way to reduce the hitching effect, its still there but its quite bit better now. VANISHING OF ETHAN CARTER(UE4 VERSION): 2 thumbs up/PAGE 16-18 FOR RUNDOWN - FINAL - RESIDENT EVIL 2(2019): Very good scaling but I can not get rid of the massive flickering and other major graphical problems like texture disappearing, and other things, NOT Recommended. (UPDATE 10/13-19): Re-tuning bits, fixed alot of stuff, on hold for now) BF 3: Great Scaling! Check pg 3. RISE OF TOMB RAIDER - (3/29/19): Before, the scaling ran eh to so so if only use smaa, now if you use SSAx2, the scaling is very good. I did however did another change in the sli hack bits, now with SMAA, the Scaling is an absolute beast but needs work around it, can't just turn on game then play, absolutely not. Please read later on this thread, it describes the vastly improved scaling I discovered, Highly recommended.. - UPDATED ON - (6/12/19) - (Check PG. 5 - FINAL -) SHADOW OF TOMB RAIDER: Very good overall scaling. 2 Profiles were custom made, one performance profile(some flickering involded) and the other a normal one(no flickering) - See page 5 for complete rundown - FINAL - (7/1/19). DEAD SPACE 1 - (6/3/2019): EXCELLENT SCALING - (CHECK PAGE 4 FOR RUNDOWN). ELDER SCROLLS V: SKYRIM(SE): Some graphic problems here and there, overall scaling ok to decent. CATZILLA BENCH: Very good to Excellent Scaling. One thing I need to point out about this benchmark, Best time to do this bench mark is on a clean install because soon as you install your Chipset drivers, It will NOT launch at all, you will get an error screen, I already confirmed this months back, Intel Chipset drivers is the root of cause, I have c612 chipset, so it may work with other chipset, just heads up. HITMAN: ABSOLUTION(ENHANCED) - UPDATE ON (6/5/2019): EXCELLENT, Check page 4 for rundown. HELLBLADE - Acts like 3 way, although 2 way works perfectly but certain things needs to be changed in the configuration folder, TAA needs to be turned off and other things needs to be shut off, otherwise Tons of graphical problems, Overall experience with this game in 4 way = Pass. I'll see what I can do to make it work but at this time, PASS. - FINAL UPDATE ON HELL BLADE UNDER 4-WAY CONFIGURATION - (6/25/19) - SEE PAGE 5 FOR MORE). LORDS OF FALLEN = DAMN GOOD! - (UPDATE 9/25/19) - CHECK PAGE 9/10 MGSV: THE PHANTOM PAIN = X FARCRY V = X DMC IV BENCH: Perfect Scaling! ALIEN ISOLATION: Seems I only get like up to 3 way performance, I have figured out how to use TAA under Sli and it works but despite the gpu usage all saying 96-98%, performance scaling is like 2-3 times over a single card. More testing is needed on this game. GOW 1: Very good Scaling, check pg 3. F1 2014: Sparsegrid Injection has to be used in order to scale well, overall = EH. RESIDENT EVIL 6 BENCH: some parts scales very well, some places no. UNIGINE HEAVEN 4.0 AND VALLEY: Prettie good. PREY(2017) = X MIRROR'S EDGE CATALYST = X(May go back in the future) ACE COMBAT 7: Terrific scaling potential, major flickering(Will go back on later time). COD: INFINITE WARFARE: Never had Sli implementation to begin with, even if it does scale, like 10% if that, Not recommended even with 2 way at this time. (UPDATE ON 1/2/20 - GAME IS NOW BEING RE-TUNED, EXCELLENT SCALING, WORK IN PROGRESS, CHECK PG 19). NIER AUTOMATA: Very good scaling. METRO 2033 REDUX(DX10): I tried doing 4k without SSA = eh scaling, then I tried 4k with SSAX2 scaling is decent but takes to much of a hit in performance, so what I did is I tried @ 2560X1600 resolution with ssaX2 or X4, scaling is alot better, overall good @ 1600p + SSA. NIOH : Excellent(3-Way Only/60 fps cap)/Working on stability/check pg 13). RYSE: SON OF ROME: Behaves more like 3 way, I'll do more tuning on this game later, more then likely = X - (UPDATED ON 6-13-19 - pg. 5 - FINAL - CASTLEVANIA: LORDS OF SHADOWS: Very good scaling, but make sure you inject SGSSAA to make better use of the scaling. BATTLEFIELD IV: EXCELLENT! CHECK PG 3. MIDDLE EARTH: SHADOWS OVER MORDOR: So So to decent. QUANTUM BREAK = X DOOM: Not really, best to use 2 way at this point. THE DIVISION = X ASSASSINS CREED ORIGINS: Scaling seems good but Massive flicker, I can not get rid of it, Not recommended at this time. (UPDATE: 9/3/19 - Check page 16(Game on hold). FARCRY PRIMAL: Up to 3-way only, check pg 5. MASS EFFECT 2: (3/23/19): Mass Effect 2 - with Alot texture mod, modified .ini file. Very Very good scaling here. For some odd reason or reasons, Sparsegrid AA does NOT work above my native resolution, wether through custom resolution or through DSR. I tried different sli bits, aa bits = no go Either one card or sli mode, doesn't matter however, I did override AA with 2x2 Supersampling and it works great, confirm it works. MASS EFFECT 3: (3/19/19): Mass Effect 3: With Alot texture mods, and tons of other mods + modified .ini file. For some reason, It only scales from 50% to mid 70% on all 4 gpu's. I even tried to inject 2x2 SS or X4 Sgssaa + 4xMsaa = no go. I tried doing some stuff to the .ini = Same Results. I tried many different variations within nvidia inspector SLI Dx9 Broadcast and Sli Dx9 Hack bits and changing many different sli profiles = same results. I literally gave up on this, kinda funny where I got ME1 and ME2 to scale very very well and this don't scale worth crap, if any, more like X 2.5 scaling over single gpu. I literally tried many variations, just gave up on it, worth trying though. I also tried to turn on through nvidia control panel, Compute Performance to ON, made it worse, infact, that particular settings can make many games lose performance so watch out, the only game that benefit this from what I have tried is The Division(in 2-way sli). Also tried to change it to 4-way sli alternate frame rendering 2 through control panel = same results. Also tried doing SFR = X. Tried doing SFR/AFR Combo = X If anything changes within this game, will give heads up, as it stands = X(Not recommended for 4-way sli, I would stick with normal 2 way sli for this game. (SEE PAGE 6 FOR FINAL UPDATE ON SCALING). YAKUZA KIWAMI 1 - DECENT, check page 3 for rundown. GTA V: Very good to EXCELLENT/check pg 19. - FINAL - UPDATE ON FARCRY 4(4/23/19): I will be needing more further testing on this, but early testing on this game, the scaling isn't all that good, scales like up to 60%+ on all gpu's, and initial testing shows and just like crysis3, If I use TXAA, the gpu scaling gets worse, I have to turn it off or use SMAA. Also, Farcry 4(Uplay), I have to set both of my cores to 2, so this means 4 cores, 8 threads, otherwise the game WILL NOT LAUNCH. Assassins Creed: Unity is the same thing but If I remembered Correctly, that game can go only high as 16 core, 32 threads, Otherwise the game WILL NOT LAUNCH, either 8 core or 16 core, I forgot but I will be testing that game later. The only time it scales like 98% on all gpu's, is at the title screen or while viewing the option window, other then that = X. Much more further testing is needed for farcry4, Will defin't give heads up later but initial testing = DUD. UPDATE ON FARCRY 4 - (4/24/19): Some scaling seems ok when your looking at ceiling, or in small rooms but when you start to move, at a certain point, it acts up, I changed some of my settings, the AA is causing some of the weak scaling, so I turned it off. I changed Both Sli hack and broadcast bits, changed sli dx11 profiles, did some workaround, = X. When you venture outside, it behaves like 2-way sli, in closed area, you might get up to like 3-way scaling. Also, you can inject Sgssaa in this game with enhance AA through nvidia inspector and use X2msaa ingame BUT it don't work when you use sli, single mode works perfect with Sgssaa. For 4-way sli = NOT RECOMMEND. UPDATE ON FARCRY 4 AGAIN ON (4/25/19): For the most part, I have gotten 4 way sli to work, However you MUST use SGSSAA+ingame MSAA to keep the scaling packed down, otherwise just straight 4k with no AA or just smaa, Scaling doesn't keep up well. How does it scale now??? I would say all in all, Decent to Prettie darn good, But it depends what your doing and looking at in the game, its not constant good scaling, some areas are Very good scaling, actually almost perfect scaling, others areas and situation are Decent. One card, while playing in one area, I get 16-17 fps, with 4 card doing the same situation = like mid 50's to low 60's. In one area I was looking at the hill side, I got like perfect scaling. Remember This is @ 4k(2400p) With x2 SGSSAA + ingame x2MSAA, so there will be performance hit here. There were Couple instances where the game just went black screen, and I has to do hard system reset, I changed certain settings within nvidia inspector and change the voltage slider a bit within afterburner, seems to run alot better now, and yes I have gotten SGSSAA + MSAA to work under SLI, All in All, Do I recommend using it with 4-way sli = Yes, Give it a try. Yes I have Confirm that SGSSAA + MSAA is working under 4-way SLI. Overall, alright experience. BLACK MIRROR IV = X ASSASSINS CREED UNITY - UPDATE ON (3/26/19): Game Tested @ 2560X1600 resolution. Tried alot for this game. It only scales up to 3 way if possible, barely even using the 4th card if any. One thing I found out that If you inject through nvidia inspector SGSSAA+MSAA = Gpu usage fluctuate or behaves very abnormal, to fix this, use only enhance the aa within inspector and use SGSSAA only instead, then use ingame AA of your wish, try to stick with like within inspector for example, 4xSGSSAA then in the game, X4msaa, I confirm it does work, you can even enhance with ingame TXAA with SGSSAA within nvidia inspector, it works. Gpu usage is like up to 70's if lucky. I already got a baseline with one gpu, like 15 FPS(x4 SGSSAA + ingame TXAA), with 4 cards it gives me like 41-43 fps. I even just tried with ingame X4 msaa = no go. Just for added kicks, used Compute perfomance to on, = no change, did 4 way alternate frame rendering through nvidia control panel = no change. I even change the quality settings under advanced to see if the scaling is affected by any of these settings, nope, all good. Tried tons of variations with Sli hack and Broadcast bits, Tried many different sli dx11 profile, along with my own custom that's not on the list, still = X At this point, I do NOT recommend at this time with 4-way sli, perhaps with 3 way but not 4 way. If anything changes later, I will give an update but I highly doubt anything would change. ALAN WAKE: Up to 3-way only, check pg 7. FARCRY 3: Blood Dragon DLC - UPDATE ON (4/9/19): Actually this Update is like a almost a week old of testing: Ok far as scaling goes, Certain parts of the game scales extremely well, Certain parts like in the beginning, when your getting near the Garrison Area, man, Scaling weakens BIG TIME. I tried changing all of my settings to the lowest then work myself up to see what is causing the scaling issues. At first, There is a setting for Water, this MUST set to low, other wise, it doesn't matter if your not near water area, The scaling weakens, so this MUST be set to low, no exceptions. In corridor areas, for the most part, scales prettie decent, The chopper part with the gatling gun, in the very beginning, don't scale worth crap, right when you get off the chopper, it scales rather well, it just doesn't scale well when you are getting near the garrison(base) area. Another area scales extremely well is right in the beginning of the a particular cave scene, namely the blood dragons, mission 2 area, that part scales extremely well, soon as you go outside, scaling starts to weaken a bit here and there, when you are getting near the base nearby, the scaling nearly cuts over half or so, there is something in the scene that's causing it to drop, I tried changing all my settings lowest to highest, by each individual settings, NOPE. I tried changing Many Sli broadcast and hackbits, changing sli profile bits(even making my own), Nope. So as it stands, Do I recommend it in a Long run? Nah, for testing purposes yes, but overall scaling at all times, No, only certain areas scales well, certain areas absolutely not, its a toss up, either you can deal with it or not, Do I recommend it at this point? Not really. SEKIRO: SHADOWS DIE TWICE - UPDATE (4/9/19): Actually this update is several day old, just didn't get around of updating it here: For the most part, I have gotten the scaling pack down rather very very well, there is one problem, Flickering can be out of control on the main charc and some textures on the screen, I tried putting all settings to their absolute lowest and fine tuned each setting by themselves, nope, Even tried the old fashion method, Cntrl + ALT + Del, then go back into the game to see flickering goes away, NOPE, Actually at one point I got the flickering to go away completely, I was messing around with the camera with my mouse, moving around a bit, going into water, etc, changing angles, then all the sudden the flickering all went away, ever since then I can not re-create it. Is it playable in 4-way? Absolutely yes, but for most people, the flickering can be an issue, if you can deal with it other then that, it scales extremely well. Also, I tried Changing many Sli hack bits and broadcast bits, sli profiles, the flickering is still present and the only profile that can really push all 4 cards is the Battlefield V profile, I did try using the Dark souls III profile at first, There is no flickering at all BUT scaling on each card is like upper 20's to low 30's, Absolute Trash scaling, mise well be running one card, but BFV profile scaling wise is a Beast. UPDATE ON: 9-24-19, CHECK PG 8/9 - FINAL). UE4 Engine Demo: Infiltrator - UPDATE ON (4/10/19): No matter how hard I try to tune this game, I can get only up to 2-way performance, NOT RECOMMENDED. STRANGE BRIGADE - UPDATE ON (4/10/19): I tried both DX12 and Vulkan API. Vulkan is locked to 2 gpu's while DX12 = X BRIGHT MEMORY(BETA/RELEASE IN 2020): Some part's scaling is wicked, some still needs work on, that being said, game is still early and game is not even done tuning(TUNING ON HOLD/CHECK PG. 8 FOR RUNDOWN).