Gadgetory

hey everyone i am steve from gamers nexus nada and today we're looking at the gtx 980ti video cards in sli that's two of them i found out we had a second one so we did an SLI test and I tested these in SLI against two gtx 980 s at titan x of course and then a whole suite of other video cards we didn't include some of the lower end cards because they're out of the price range of this so for SLI testing we're mostly looking at the 980 TI is of course and the 980 s and the price drop of $50 brings the 980 down to 500 dollars for a single card it's $1000 for SLI in this case there's six fifty each so that's thirteen hundred dollars for SLI and the Titan X is a single video card solution at about $1000 flat betting on who you buy from and the type max we already talked about is sort of invalidated as a value by card and this is because the 980ti is $350 cheaper and gives about the same performance in most games so the only place you're buying to type nice at this point is if you're planning to do SLI of those because that would give you a tremendous performance output that you don't get from some of these other solutions so to quickly recap the specs of the gtx 980ti it's got 28 16 cuda cores the titan max has 30 72 the nine 80s a little bit lower than both of those and the base clock of the 980ti is a thousand megahertz so we ran these tests at the 1,000 megahertz base clock and bruised is 1075 or something like that I've got an overclocking video already on the channel check out the channel if you're curious how the 980ti overclocks it was pretty good it was about a 40% OC in terms of clock rate so about 20% game so that's the recap of that we've done SLI testing a few times on the channel now but let's just quickly recap how SLI works SLI is an invidious form of a multi GPU solution it uses a scalable link interface bridge or sli bridge to connect two or more video cards for sharing and processing power and things like that and these solution is called crossfire on paper they perform pretty similarly in terms of how they interact with the bridges do but in practice it's really down to drivers and game implementations to dictate how SLI crossfire whatever multi-gpu solutions actually perform in game SLI bridges the video card so they share pixel processing power and other processing power they do not share video ram so vram does not stack we don't get 12 gigabytes because we've got 6 & 6 in this case GTA 5 is an interesting game and that it shows your vram consumption as a slider bar and this is actually a pretty cool thing but it's a little bit wrong in that it shows the stacked video RAM value so if you've got two cards at 6 gigabytes each it'll show 12 it's not really how it works you don't get to use 12 gigabytes just because you've got two sets of six in your solution but with DirectX 12 things are changing and that's because of a couple of things dx12 is introducing a lot of stuff like split frame rendering instead of alternate frame rendering which is what we use right now and it's also going to allow sharing the video RAM between solutions and further it'll allow using non the same brand video cards for SLR crossfire configurations and in theory you could combine AM D and Nvidia in a single multi-gpu solution with DirectX 12 whether this will work is sort of a question of drivers and game optimizations but on paper it as possible the current AFR alternate frame rendering version of SLI introduces some low 1% and 0.1% frame rate outputs for gaming so this is a question of frame times the 99th 99.9% I'll frames are sometimes lower in performance than a single GTX 980 or 98 TI for instance and this is because of CPU overhead DirectX API overhead which we've done a video on and other inefficiencies in the pipeline a lot of which will be resolved with dx12 but dx12 isn't a magic bullet we've got bottlenecks elsewhere like lane availability with Haswell the non eversion has well they're only 16 PCIe lanes on the CPU and eight on the PCH platform controller hub also known as the chipset the current line series chipsets by Intel the h 97 and z97 chipset offer eight lanes so we've got a total of 24 16 CPU a chipset and that's not enough to do by 16 by 16 x16 x16 if you want to call it that GPU configurations for multi GPUs and this is something that's a bit curious so you've seen some motherboards like our gigabyte z97 X board we bought for testing will actually list x16 x16 as a possible configuration for multi GPUs and you're honoring how this is possible when there aren't 32 lanes available it's because of multiplexing so you can have Apex chip on the board and that's this is what it looks like it's made by plx and pecks multiplexing is basically taking multiple erotic signals converging on one point and it outputs a single signal and then does what's called switching so in the device manager you'll see PCI downstream switch ports these are the device manager representation for what's going on when you're multiplexing your lanes and multiplexing lanes basically means that you're optimizing the land division between multiple ports for multiple devices so if one device is more heavily loaded than another the multiplexing chip will divert some of the lane availability to the more heavily loaded device and take away from another device that is less heavily loaded and this is just an optimization technique that doesn't create more lanes so if all devices are under full load it's not going to help you there but it does effectively artificially produce more lanes strictly in the fact that it optimizes where the lanes are divided between devices depending on which board you're using it's questionable how much of a performance gain this gives you and depending on what gq-- you're using because if you're loading all of your GPUs it doesn't do anything for you but it is a technology that we use in our test motherboard because we've found that it actually does allow for like four-way SLI configurations on z97 without too much of a performance hit let's talk about the benchmarks now for the 980ti is in sli so these benches were run in comparison to our previous 980ti single solution and 980 sli solution in our testing sli generally saw a rough sixteen to twenty percent increase in performance over to a gtx 980 non ti sli and it's a noteworthy game but values still questionable because it's at $1,300 the TI versions raise a thousand for the sli 980 s one thing that does become clear though is that a single Titan X has really pretty poor value right now with the launch of the 980 TI and the price drop of the 980 but multiple Titan X's would offer unachievable performance elsewhere so if you're looking at that as a solution it's still valid it wouldn't be great value but you get the performance and at that point you really don't care about value if your SLI in Titan maxes it's not a thing you're concerned about in some of these charts you'll notice that sli 980 s and sli 980 TI s perform effectively identically and this is strange on paper it's likely due to CP bottlenecking on a 4790k Seaview or software side bottlenecking in the games but most games sans Metro have 1440p and grid at 4k show a healthy difference in performance upwards of about 20% as I said you can view the full article link in the description below on the website where we have all the charts test methodology things like that we explain the 1% immerse point one percent frames and now it's just a matter of value so is it worth it with 980 TI is in sli you're spending $1300 versus 980 s in SLI at $1000 the Titan X we sort of rule out at this point because a single GPU solution if you're buying just one of them it's not good value even against a single 980ti which is $350 cheaper and performs pretty close just has half the vram a 20% gain for $300 is questionable I think for a lot of system builders but if it's not for you that it's a good solution you're gaining about point zero six percent per dollar if you look at it that way and although the value is questionable at $300 gained over 980 is in sli that's really up to you to decide if that's worth it one thing I will say is that for the first time in my benchmarking history far cry 4 was actually producing a fluid and playable framerate without the odd stuttering and hiccuping that we normally get a 4k testing so that was thanks to the ti SLI version 9 80s and SLI are pretty similar but you have to drop a few settings to get what I'm talking about and then single GPU solutions really kind of struggle at 4k in Far Cry 4 so that is our 980ti sli benchmark you can check the link in the description below for the full article thanks for watching as always a huge - icon Greg and Rob for being our first three patreon backers it's a big help to have the support of the viewers and community so we can rely more on you guys and less on advertising which is pretty important because we do post a lot of critical videos so that is all for this content if you like this type of stuff check the channel for more 980ti information sorry I'm a bit nasally I'm pretty sick right now but that is all for this time I will see you all next time you