TechSpot

GTX 670 SLI

By Alpha Gamer
Jun 6, 2013
Post New Reply
  1. JC713

    JC713 TS Evangelist Posts: 6,982   +909

    Yeah it is off topic, but one more comment. Why would the memory controller need to be built in? Sorry Alpha Gamer for taking your thread off topic a bit.
     
  2. dividebyzero

    dividebyzero trainee n00b Posts: 4,869   +697

    An external MC (or multiple MC's in a GPU's case) adds complexity in production (cost, data and power) and adds latency (distance between MC's and caches etc). Neither are particularly desirable.
     
  3. Alpha Gamer

    Alpha Gamer TS Booster Topic Starter Posts: 249   +45

    Not a problem at all, I enjoy reading all sorts of subject derived from my question. Thank you for coming back :)
     
  4. JC713

    JC713 TS Evangelist Posts: 6,982   +909

    Very interesting. Thanks.
     
  5. Alpha Gamer

    Alpha Gamer TS Booster Topic Starter Posts: 249   +45

    Guys, I'm back with more questions, if you allow me.

    I've read a couple of reviews on SLIed gtx 670s running on 1080p systems and according o them, those twins rock the house. But there's something I'm SUPER worried about: micro stutter. I don't know if I got it right but I understood it's a problem caused by (inconsistent/high?) frame latency. And it would be more likely to happen on a dual gpu setup than in a single one.

    Those were the reviews I read 1 and 2.
    Number two mentions the frame times issue.

    But, according the graphs throughout this review, the gtx 660 ti SLI frame times rival the titan's. So I would expect something similar, or even better from gtx 670 SLI.
    Can anyone shed some light on this subject?
    If I'm misunderstanding some very clear information about this matter, please forgive me. English is not my native language and more than often I get lost when reading long technical information.

    On a side note: I won't deny I'm itching to get a 2nd card, but I'm very sensitive regarding microstutering, deep frame-rate dips and the like. And I know it would ruin my gaming sessions, even though the framerate would be higher. Me and a friend, we both own twin systems, we assembled them together. And I always play my games at lower settings than his, just so I won't have too much framerate inconsistency. And the funny thing is he plays with astronomical levels of anti-aliasing cause he can't stand the "horrible edges" I won't even notice. Guess people are different...
     
  6. JC713

    JC713 TS Evangelist Posts: 6,982   +909

    dividebyzero can explain latency issues very well :). I thought you already knew about those issues so I never mentioned them. Micostuttering is not the only issue you can expect to occur with SLI/xfire setups. You can expect to recieve driver issues sometimes. Also, you will need updated profiles every time a game is released (I am not 100% sure what they are for, so I do not want to tell you the wrong info). Modern engines/drivers have greatly improved multi-GPU scaling, but some games still dont scale well. You can read on multi-GPU issues here: http://www.tomshardware.com/reviews/amd-crossfire-nvidia-sli-multi-gpu,2678.html
     
    Alpha Gamer likes this.
  7. dividebyzero

    dividebyzero trainee n00b Posts: 4,869   +697

    The bad news is microstutter is real, the good news is that Nvidia's Kepler based cards implement adaptive V-sync and their frame metering is improving pretty well.
    The issue is the same for all multi-GPU setups where AFR (alternate frame rendering) is used. One GPU rendering at a faster rate than the second, third etc. Basically what happens is that the second card renders its frame and the data is transferred to the first cards memory. Delays in getting the transfer done, as well as unequal card performance then lead to stutter where the cards aren't delivering their frames at the same rate. Adaptive V-sync smooths out the time interval, and unlike traditional V-sync doesn't have such an issue with input lag.
    If you're very sensitive to microstutter I'd steer clear of multi-card setups of any variety (although the GTX 690 seems to be the exception that proves the rule in most cases). The issue might not be across the board, but it could occur in enough games to make you have second thoughts about buying the second card. At least you can disable SLI and nominate the secondary card for an overqualified PhysX card I suppose.
    I'd recommend reading through Scott Wasson's and Ryan Shout's methodology for measuring frame latency/metering and microstutter. Remember that this is an on going process so information becomes outdated very quickly as frame latency becomes an important metric for comparative benchmarking.
    This series gives a comprehensive overview of the situation at the present time
    Yes. depending on the SLI scaling of the game involved which can run from zero to 100%.
    Any game that offers an additional ~45-50% increase is on par with a Titan in raw framerate (for intents and purposes GTX 670 OC SLI is equivalent to GTX 680 SLI or a GTX 690). The Titan is still going to benefit from its large framebuffer when taking into account antialiasing and post process image enhancements though.
     
    Alpha Gamer likes this.
  8. GhostRyder

    GhostRyder TS Evangelist Posts: 2,223   +528

    Micro-stuttering is a new thing that people are obsessing over, its honestly not near as bad as people make it out to be. Both AMD and Nvidia have made strides in both respects at fixing the issues that people label as "Game Breaking". But honestly, most people overreact and now base everything off of numbers and claims that they see in game. Personally, I run Dual HD 6990s (4 GPU's) and ive never had an issue other than a few times of bad crossfire support. The 670's and such are great in SLI and really don't show any signs of weakness in that respect. Its really an issue added in the last 2 years because of extreme resolution/refresh setups, but has become some world ending issue with cards.

    Honestly, with 2 670's, you wont see any issues and would just have a great gaming experience. I personally don't think you should worry about it.
     
    Alpha Gamer likes this.
  9. Alpha Gamer

    Alpha Gamer TS Booster Topic Starter Posts: 249   +45

    Thanks for the links, I'll take my time to read them.

    Does it mean microstuter is less likely to happen in more modest resolution/refresh setups?
     
  10. GhostRyder

    GhostRyder TS Evangelist Posts: 2,223   +528

    Honestly, the higher the resolution, the more likely you are to get a "Micro-Stutter" effect that people describe. However again, its not as big an issue as some people make it out to be and its very hard to notice unless you run very extreme resolution setups (Mostly because GPU's re just starting to be able to hit those areas).

    Heres the easiest way I can describe what micro-stutter is (FYI Excuse this example, I agree its a weird way of describing this):
    Imagine your in an office stamping papers and you have an assistant running the papers to you at a very consistant pace. Now while your doing this, the assistant trips and falls delaying the next paper to you by one micro second and this happens every 100 papers give or take. Now lets say you add a second assistant to the group and now they both run into eachother/trip every 60 papers or so but the papers are getting to you faster. If you put the person stamping as the monitor and the assistants as GPU's, that's a very basic description of it.

    Ok I know im not the best example maker lol, but anyway like I said its not as big as a lot of people make it out to be and its going to depend on the reviewer and what software is used to measure it, etc. Some sites view it differently than others and some see things as worse than others etc. 2 670's will not be bad for you and you wont see any stutter (It would be so abysmal and small) so you should not worry.

    That's just my two cents on the matter, but theres always different opinions/views that say things are different then I say, so yeah.
     
  11. Alpha Gamer

    Alpha Gamer TS Booster Topic Starter Posts: 249   +45

     
  12. JC713

    JC713 TS Evangelist Posts: 6,982   +909

    Usually drivers can fix micro-stuttering to an extent. You will just have to endure it until it is fixed.
     
  13. Alpha Gamer

    Alpha Gamer TS Booster Topic Starter Posts: 249   +45

    I'd love to learn more about this as well, does anyone know where I can find detailed info about this? Maybe it's in one the links already posted on the thread and I just haven't had the time to read it yet.
    You mean the drivers are released with a particular game in mind or "drivers fix micro-stuttering" in a general way?
     
  14. JC713

    JC713 TS Evangelist Posts: 6,982   +909

    Well, I know they fix latency issues with drivers. They optimize drivers for a game usually, and the next major release after game optimizations is usually a latency optimization.

    This should explain your questions: https://forums.geforce.com/default/...unge/nvidia-multi-gpu-sli-physx-setup-guide-/.
     
  15. GhostRyder

    GhostRyder TS Evangelist Posts: 2,223   +528

    For some good examples of seeing things in action, check out the reviews section on video cards on this site:
    http://www.techspot.com/review/678-gainward-geforce-gtx-770/

    They show how each card performs according to their standards and at 2 resolutions. Each update always improves somthing, and the improvements to Micro stutter gets better each time for all cards.

    Also, if your worried at all, the best way to make sure to avoid as many issues as possible is Vsync, especially on the nvidia cards using their adaptive vsync is real nice. Just set profiles for each game to make sure the adaptive vsync is on and you will get smooth sailing.
     
  16. Dawn1113

    Dawn1113 TS Booster Posts: 375   +64

    +1 for adaptive vsync. Much better now.
    I agree with JC713's point about drivers fixing micro-stuttering to an extent after a while. I've come across some games where micro-stuttering was pretty bad at first, then subsided after a few new driver releases. For older games -- BF3, for instance -- I hardly notice any micro-stuttering anymore. But then that is my opinion and one person might be more meticulous about these things than the next.

    I have two 670s running on a 1080p 60Hz monitor. I've been quite pleased with GPUs thus far. I don't think the resolution pushes them too much, though. I just played a few hours of Metro Last Light and had some fun. No game-breaking issues there -- just had to disable SSAA.
     


Add New Comment

TechSpot Members
Login or sign up for free,
it takes about 30 seconds.
You may also...


Get complete access to the TechSpot community. Join thousands of technology enthusiasts that contribute and share knowledge in our forum. Get a private inbox, upload your own photo gallery and more.