1. Welcome to TechPowerUp Forums, Guest! Please check out our forum guidelines for info related to our community.

Some questions about GTX 770 SLI

Discussion in 'Graphics Cards' started by Rubnik, Aug 2, 2014.

  1. Rubnik

    Rubnik

    Joined:
    May 3, 2013
    Messages:
    29 (0.05/day)
    Thanks Received:
    1
    I'm thinking of getting a second MSI N770 TF 2GD5/OC, in order to run latest games at ~120 fps without having to reduce graphics quality much.

    First of all I need to upgrade my 650W psu. I was thinking of getting a Corsair RM850,since it seems to have very nice features for it's price. Any feedback on this PSU or other suggestions would be appreciated.

    Secondly, i run my 770 slightly overclocked(apart from the factory OC).Do i have to match the Core and Mem clocks in both cards?

    Last, my motherboard (MSI Z87 G45) did not come with an SLI bridge, even though it supports it. If I get a non flexible SLI bridge, like those fancy EVGA Pro ones, do i need to worry about the distance between the headers? The 3 way one has 80mm distance between the fingers while the 2way one 60mm. My gpus are going to have 2 PCI 1X ports between them as seen here. Although i guess i can just measure the distance between the PCI slots I'm going to use, when I get home.

    My system specs are :
    4670k CPU
    GTX 770 GPU
    MSI Z87 G45 mobo
    8Gb Ram
    144Hz Monitor
     
  2. newtekie1

    newtekie1 Semi-Retired Folder

    Joined:
    Nov 22, 2005
    Messages:
    20,029 (6.15/day)
    Thanks Received:
    6,094
    http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=369 <-All you need to know on the RM850. Seems like a good unit.

    It is best for both cards to run at the same clocks. In fact most overclocking software will automatically sync the clocks by default.

    You will have to get the correct size SLI bridge. The best way is to measure the distance between the PCI-E ports like you said.
     
    Crunching for Team TPU 50 Million points folded for TPU
  3. GhostRyder

    GhostRyder

    Joined:
    Apr 29, 2014
    Messages:
    1,146 (6.51/day)
    Thanks Received:
    422
    Location:
    Texas
    It's not a requirement to run then at the same clocks it just means you will be running at the power of the lower frequencies card (unless you manually adjust both cards frequencies).

    As far as power usage, it would be safe for at least 750+ (probably a gold rated) to maintain everything overclocked. An 850 would of course play it much safer and allow the psu to be under less load which would be my personal preference.

    Edit: yea that's actually more standard than I thought... I'm still stuck in the old ways.
     
    Last edited: Aug 2, 2014
  4. newtekie1

    newtekie1 Semi-Retired Folder

    Joined:
    Nov 22, 2005
    Messages:
    20,029 (6.15/day)
    Thanks Received:
    6,094
    :wtf: That is the standard spacing for ATX boards these days. The eVGA 2-Way Pro bridge would work with this configuration.
     
    Crunching for Team TPU 50 Million points folded for TPU
  5. Rubnik

    Rubnik

    Joined:
    May 3, 2013
    Messages:
    29 (0.05/day)
    Thanks Received:
    1
    This seems to be the case. Looked at some Z87 boards, most have the same distance between the first two 32x slots.Between them there is usually one 1x slot, while mine has two, but the distance seems the same.
     
  6. GhostRyder

    GhostRyder

    Joined:
    Apr 29, 2014
    Messages:
    1,146 (6.51/day)
    Thanks Received:
    422
    Location:
    Texas
    I guess now that I look more boards are like that than I realized. I thought most still stuck to the standard 2 slot.

    Guess I need to catch up with the times lol.

    But the standard was usually pcie 16x pci-bus or pcie 1x, then another pcie x16. These gaming boards now have started accommodating 3 slot cards more...
     
  7. MxPhenom 216

    MxPhenom 216 Corsair Fanboy

    Joined:
    Aug 31, 2010
    Messages:
    10,044 (6.64/day)
    Thanks Received:
    2,264
    Location:
    Seattle, WA
  8. FreedomEclipse

    FreedomEclipse ~Technological Technocrat~

    Joined:
    Apr 20, 2007
    Messages:
    13,841 (5.05/day)
    Thanks Received:
    2,335
    buy a pair of 4GB 770s, might cost more but in the long run you'll be thankful that you did if you ever should go 1440p
     
  9. Rubnik

    Rubnik

    Joined:
    May 3, 2013
    Messages:
    29 (0.05/day)
    Thanks Received:
    1
    I don't think my TX650m can handle 2 770s.Even if it marginally can, I dont think it has the connectors.

    I wanted to ask about those PSUs.Glad you brought that up.I'm a bit concerned about the RM850 because, my experience with the Zero RPM feature wasn't good on the TX650m.I'll definatelly give it a look.

    You have a point,but i bought this screen a couple of months ago, so i doubt i'll be going 1440p any time soon.
     
  10. MxPhenom 216

    MxPhenom 216 Corsair Fanboy

    Joined:
    Aug 31, 2010
    Messages:
    10,044 (6.64/day)
    Thanks Received:
    2,264
    Location:
    Seattle, WA

    Id probably get the Evga G2 750w. Its $120 on Newegg right now, and wil lbe able to handle the 2 770s with ease!
     
  11. newtekie1

    newtekie1 Semi-Retired Folder

    Joined:
    Nov 22, 2005
    Messages:
    20,029 (6.15/day)
    Thanks Received:
    6,094
    The TX650m can easily handle your rig with two 770s. You're only looking at about 360w for the two GPUs and maybe 175w for the CPU and everything else. My main rig, with GPUs very similar in power consumption to 770s and the overclocked 4790 only pulls a max of 600w from the wall and that was just a peak I saw once, when gaming it never breaks 550w.

    As for connectors, you've got two 8-Pin PCI-E connectors. You can use those with inexpensive splitters to give you the needed four 6-pins.

    I mean, going from a TX650m to something like a G2 750w, you're only gaining ~96w of extra power. That really isn't that much of a difference in the big picture.

    Edit: What I'm really trying to say is don't bother upgrading your PSU for such a small gain, it isn't worth the hassle, or money, and you don't really need to upgrade. If you do want to upgrade your PSU, go big and get at least an 850w unit, like the RM850 you were originally considering.
     
    Last edited: Aug 2, 2014
    MxPhenom 216 says thanks.
    Crunching for Team TPU 50 Million points folded for TPU
  12. FreedomEclipse

    FreedomEclipse ~Technological Technocrat~

    Joined:
    Apr 20, 2007
    Messages:
    13,841 (5.05/day)
    Thanks Received:
    2,335
    but what if you see the screen going cheap and buy another 2? Trust me 3-4GB is the standard. Youre going to be running these 770s for a while as they have a good level of performance in SLi and they're dirt cheap now so why not prepare for the road ahead too while your at it? Unless you plan to upgrade again 6 months down the line.

    If youre only playing 1080p than you might as well just grab a 290X or 780Ti. Neither of them will beat out 770s in SLi but you dont really need the horsepower that the 770s provide at that res.


    Its up to you anyway. I went 1440p a few months ago and even though my 680s are an impressive pair, the 2GB of ram becomes a serious limiting factor.

    If you play Skyrim or fallout 3 with a tonne of mods and stuff more V-ram would help too.
     
    GhostRyder says thanks.
  13. MxPhenom 216

    MxPhenom 216 Corsair Fanboy

    Joined:
    Aug 31, 2010
    Messages:
    10,044 (6.64/day)
    Thanks Received:
    2,264
    Location:
    Seattle, WA
    Dude he's running a 144hz monitor. He's pretty much going to need to run 2 cards regardless of what he gets, if he wants to utilize that refresh rate effectively.
     
  14. Rubnik

    Rubnik

    Joined:
    May 3, 2013
    Messages:
    29 (0.05/day)
    Thanks Received:
    1
    I guess i could look for something like this. I thought this wasn't very safe to do, but after a quick search I didn't see anyone having problems with it.
     
  15. Aquinus

    Aquinus Resident Wat-man

    Joined:
    Jan 28, 2012
    Messages:
    6,456 (6.47/day)
    Thanks Received:
    2,177
    Location:
    Concord, NH
    Just because people haven't had problems with them yet, doesn't mean that they won't. I've heard of people's connectors melting because the amperage was too high for the cable. Honestly, it's a fire hazard and I could never recommend it.
     
  16. GhostRyder

    GhostRyder

    Joined:
    Apr 29, 2014
    Messages:
    1,146 (6.51/day)
    Thanks Received:
    422
    Location:
    Texas
    Your PSU is fine and you can do that based on the specs at corsair, however I am inclined in my personal opinion to say grab a 750watt minimum to handle all your overclocking and system needs. My personal assumption is to never run a PSU to close to its limits even on the very high end ones (Gold Rated+) just for life expectancy and safety for your internal components.

    I would not advise doing a splitter on something like that just because you could run into issues down the line, however it would work in the configuration listed. Its just a risky thing to do.
     
  17. newtekie1

    newtekie1 Semi-Retired Folder

    Joined:
    Nov 22, 2005
    Messages:
    20,029 (6.15/day)
    Thanks Received:
    6,094
    An 8-pin PCI-E connector, what your PSU has, is good for 150w. A 6-Pin PCI-E connector is good for 75w, and most 770s have two 6-pins. So two 6-Pins is 150w. It is perfectly safe/acceptable to split a single 8-pin into two 6-pins.

    There is no fire hazard, the connectors on his PSU are rated to handled the current.
     
    Crunching for Team TPU 50 Million points folded for TPU
  18. Rubnik

    Rubnik

    Joined:
    May 3, 2013
    Messages:
    29 (0.05/day)
    Thanks Received:
    1
    Forgot to mention, my 770 has 2x8pin connectors
     
  19. MxPhenom 216

    MxPhenom 216 Corsair Fanboy

    Joined:
    Aug 31, 2010
    Messages:
    10,044 (6.64/day)
    Thanks Received:
    2,264
    Location:
    Seattle, WA
    Id just upgrade the PSU then. Get the EVGA G2 750. It has 4x 6pin + 2pin PCIe connections. So you can use them at 8 pin when you need to and 6 pin by not connecting the 2 pin part in.

    [​IMG]

    [​IMG]
     
  20. FreedomEclipse

    FreedomEclipse ~Technological Technocrat~

    Joined:
    Apr 20, 2007
    Messages:
    13,841 (5.05/day)
    Thanks Received:
    2,335
    [​IMG]

    I didnt see he had a 144hz monitor. but definitely 4GB is the way to go.
     
    manofthem says thanks.
  21. Rubnik

    Rubnik

    Joined:
    May 3, 2013
    Messages:
    29 (0.05/day)
    Thanks Received:
    1
    Yeah that's what I'm probably gonna do and hopefully sell my old TX.Splitters don't feel right for a new pc.
    Is there any point going for 850W?
     
  22. FreedomEclipse

    FreedomEclipse ~Technological Technocrat~

    Joined:
    Apr 20, 2007
    Messages:
    13,841 (5.05/day)
    Thanks Received:
    2,335
    Not really. even my system alone barely pulls above 600watts, though I do have a 80PLUS Platinum PSU so my numbers might differ to PSUs of a lesser rating/certification.

    you could probably go as low as 650w but that would be cutting it pretty close imo. the extra power you get from a 700-750w would be to cover any sudden spikes in power draw.
     
  23. GhostRyder

    GhostRyder

    Joined:
    Apr 29, 2014
    Messages:
    1,146 (6.51/day)
    Thanks Received:
    422
    Location:
    Texas
    750 should be more than enough. I would say incest in a good 750(gold rated if you want to go big) over getting an 850.
     
  24. newtekie1

    newtekie1 Semi-Retired Folder

    Joined:
    Nov 22, 2005
    Messages:
    20,029 (6.15/day)
    Thanks Received:
    6,094
    On a card that will never pull more than 200w?! That's just...stupid!

    More headroom for the future. IMO, it isn't worth upgrading your PSU for such a little gain, I wouldn't even bother doing it for less than an 850w. The RM850 and G2 850w are both good units. I'd side with the RM850 simply because in my experience eVGA's customer service is utter garbage and Corsair's is freaking amazing.
     
    Crunching for Team TPU 50 Million points folded for TPU
  25. Rubnik

    Rubnik

    Joined:
    May 3, 2013
    Messages:
    29 (0.05/day)
    Thanks Received:
    1
    Indeed Corsair's service is pretty good, although I've seen on many forums people recommend the EVGA over the Corsair one.
     

Currently Active Users Viewing This Thread: 1 (0 members and 1 guest)

Share This Page