Nvidia's SLI Best Practices Guide has a couple of recommendations that may improve rf 2.0 performance. 1. Disable "Flush Previous Frame" in the PLR file if you have this enabled (disabled by default). ISI already recommends against this in the release notes of Build 60 "GPU sync is a UI element for the PLR’s “Flush Previous Frame” setting. This setting is not recommended for SLI." From the NVidia Guide: One of the worst ways to eliminate input lag is to force a flush at the end of every frame. Doing so stalls the CPU, flushes all buffers, then stalls the GPU. In this situation you are not only eliminating any performance benefit from SLI, but you are also incurring a performance penalty on single GPU systems since you are reducing parallelism between the CPU and GPU. This technique should be avoided wherever possible. 2. Set the number of frames buffered to the number of physical GPUs in the system. Default setting in the Nvidia driver is three. Set to two if 2 GPUs are present, three if 3 GPUs, four if 4 GPUs. From the NVidia Guide: Ideally, you want to buffer at least one frame per GPU on the system. This technique offers a good compromise of minimizing input lag, while also achieving better performance on both SLI-enabled systems and single-GPU systems. One additional detail worth noting is that while frame throughput is the same on SLI systems as it is on non-SLI systems, frame latency is reduced due to parallelism. For example, if a typical frame takes 30ms to render, the effective latency of those frames is only ~15ms (assuming an SLI system with two GPUs). Thus, increasing the number of frames buffered in SLI does not linearly increase input lag as one might expect. Actual results will depend on how well your application is scaling in SLI.
I did as you said and it does seem a bit smoother. I've been watching FPS before this and it looks to be like 3 to 5 FPS gain.
Bump. It's 2014 and rF2 is still giving me 1/2 of FPS when I dare to turn SLI on! How can we explain that? Most of games are 40 - 60% more FPS with SLI on, even rF1 (25% of gain) but rF2 cut my FPS to the half. Tried everything, researched this forum and read all possible suggests, all in vain. Am I missing something or rF2 will never be SLI capable?
it will be sli capable, but is nividia doing anything on there drivers for rf2 ?????????? i have not seen a thing personally. maybe that would help sli users more if they did.
I wonder where and who says that SLI don`t work and turning it off gives better fps. Joe Campana wrote this in may 2014: " 04-05-14, 08:27 PM Joe Campana This is nonsense, guys. Our multiGPU performance is as good, or better, than anyone and has been for a while. I have tested it extensively and consistently get 90% GPU util on both GPUs, AMD and nVidia. On my test systems, AC multiGPU does not work worth a spit. pCars is OK, iRacing works very well. Perhaps you need to add some SLI bits with inspector, although I thought the current profile handled this fine. So, do not generalize your specific HW problem to rF2 overall, because it's just not the case. " Maybe you can find some help here : http://isiforums.net/f/showthread.php/21081-SLI-is-working-SLI-Multiview-HDR
Ari sry m8 didnt mean to sound like i sli my system. just want to see nvidia help out with rfactor2 it might help us all
Yes I know you don`t. Problem with SLI is not that it don`t work, but it is huge task to make working profile to rFactor2 and it is so easy to get lost with all SLI bits and other settings
Hi folks not sure if everbody knows this thread maybe it is usefull for some of you. http://isiforums.net/f/showthread.php?t=20394 Last I want to say IMO the only solution would be ISI should made a request by nvidia for a specific SLI profile for rF2. From here a little bit offtopic (sorry about that) Personally I gave up with this topic (for now) I've changed my both GTX 670 with 2 R290x OC (1040 Mhz). I can run now full settings with triple multiview and all maxed out. Maybe this would also possible with the GTX 780 but the price difference between this both cards is huge because of this I decided to change to AMD. Yesterday I found a tool called RadeOnPro which is similar to nvidia inspector. In the meantime all my other games I use (ARMA3, AC, BF4) run flawless. It is sad that this was the only possible solution but after days of testing posting and fiddeling with this fu&@! SLI bits and no response from ISI to this topic I'm done with it. Thx ISI for your "great support". It remember me to this bird which is put his head in the sand.
Ok, where: here / who = I I removed all rF2 data and reinstall from very scratch, only ISI original material, no add-ons . SLI on is actually one third FPS than SLI off. Why would I make this of? 2 X GTX 770 OC (Gigabyte) Clio @ Lime Rock, sunny wheather, SLI OFF = 100 FPS avg Clio @ Lime Rock, sunny wheather, SLI ON = 30 FPS avg 2 X GTX 780 ti Clio @ Lime Rock, sunny wheather, SLI OFF = 131 FPS avg Clio @ Lime Rock, sunny wheather, SLI ON = 41 FPS avg Edit: Added additional test with another computer SLI setting.
Yeah, it's amazing that after years this issue lasts. Funny thing is, most of titles where SLI is well known not-working, there's no FPS decreasing, at most inducing of stuttering and other non desired effects, but not FPS cap, let alone 2/3 loss. So, what's happening in SLI x rFactor2 situation is something else.
About this, it sounds me like a joke: Who would call this as a "help"? The statement "our mutiGPU performance is good" doesn't mean anything, as "you need to add some SLI bits", if devs have so good performance why not to share the "bits" they're using? This sort of devs return, totally subjective and technically empty is what makes a lot of users angry and disappointing about ISI sometimes.
When I first read this posting, I thought it was new but realized I had read this all before. My 2-GTX 670 4GB's in SLI works really good in rFactor2 until I activate the FXAA and/or the HDR. Then I have a 30fps slideshow no matter what I run or how many. I did try the nVidia Inspector "bits" but nothing got better. All still the same.
SLI GPU load is +90% with both cards, 2-way SLI works fine and to claim that somebody gets 41fps with 2x GTX 780 ti makes me to laugh. My reply is done early on this morning, my thought was to PM you my NVIDIA Inspector profile after I am home from the work but with that attitude you reply to me you don`t deserve any better fps , you can do it like I did to get my system to work , it is just to read 100`s of pages documentation from NVIDIA and learn it the hard way. I agree about lack of support from ISI also and it seems that site leaders/devs don`t read forums at all. THE END
Antero, you don't need to get angry, don't take it personal because it isn't. My dissatisfaction is related to support that we have (or, better saying, we don't have) for a so old issue. I forgot to mention, in addition to Ropcart44 post, in fact the FPS results I posted include FXAA and HDR enable (for my taste, it's the minimum requirement to obtain a minimally decent graphics) and yes, SLI on = slideshow. I'm going to test without post effects and HDR tonight just to check this technical aspect of issue, but it's not an alternative to me because rF2 raw graphics are eyes-hurting.
Ari Antero, Are there settings that would free up the FPS when I use FXAA and HDR? It would be great to use HDR again so I can brighten up the tracks. If there are settings, I will try again. You are right about one thing, it does take a long time to not only learn the settings but to spend time tweaking them back and forth. I always hoped that ISI would make it easier to get the same results. Thanks.
Try settings made by aplha-bravo : http://isiforums.net/f/showthread.p...I-Is-this-inte?p=295180&viewfull=1#post295180 You can also try this topic, #1 : http://isiforums.net/f/showthread.php/21081-SLI-is-working-SLI-Multiview-HDR player.JSON , remeber to edit this line : "Max Framerate":60, "Max Framerate#":"0 to disable (note: positive numbers only, we always use the 'alternate' method now)",
LOL... one of Alpha-Bravo's SLI settings is "turn of SLI", in other words. Performance with SLI on or off is exactly the same because of "force one GPU render" or something like this in Nvidia Inspector. It'd be good to avoid spread wrong info.
@santangoss Would you be so kind to tell us which setting you mean exactly ^^ ? IF you mean SFR = Splitframe Rendering. This means a image is split into two parts and every half part will be rendered on one gpu. I measured always the GPU utilization and both GPU's was utilized between 97 - 100%. 2. I have pointed more then one time that the one or other setting is useless. Fact is this settings gave me on my system (at the timepoint of my posting, in the meantime I own two R290x) the best compromise between image quality and FPS. 3. You are welcome to post better settings. It sounds as you have the final solution found so please enlighten us and post your SLI setting solution here. 3, I have still my two GTX 670 and I can give back my two R290x. So I would be happy if you can tell me/us a solution and I can save the money for the both AMD cards. 4. I'm on vacating but I will try check this thread as often as possible because I spend so much time in this topic and finally a knowing is appeared. Great thx alex
