Quad 7970's How much Power?

By death791
Jun 17, 2013
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  1. Hi, I'm thinking about upgrading from 2 Crossfired 7970's to Quad 7970s, I'm currently running a XFX 1050w Power supply so I know I will have to upgrade to a bigger one, So I'm just wondering what size to go on the psu to safety run them all and the rest of my rig. Thanks alot!
  2. TechGamer

    TechGamer TechSpot Booster Posts: 408   +34

    [​IMG]

    this is an average power consumption of a radeon 7970

    u have to take count not only the graphics cards here though all ur system specs should be listed down if possible and if ur running an overclock it would help better

    but judgeing by the cards it would add up already to a 1300w alone

    + might I ask what u need quad 7970s for :D I feel like 2 is enough overkill already :p
  3. JC713

    JC713 TechSpot Evangelist Posts: 6,810   +884

    There are a lot of things to take into account here. 1) Your board needs to support quad SLI, or else your cards will run on a very slow PCIe 4x interface. 2) You need a good CPU to hold up the GPUs performance. 3) You need a sufficient power supply. 4) The heat produced form the 4 cards will be tremendous, so you need good case ventilation even though the cards have a closed shroud. 5) You should have a watercooling system in place before you get >2 GPUs in your system since it is easier to control the heat.

    What are your full system specs? What resolution are you gaming at? Do you meet all 5 of the criteria?
    TechGamer and GhostRyder like this.
  4. GhostRyder

    GhostRyder TechSpot Evangelist Posts: 2,171   +510

    Video
    Heres a youtube video that can give you a rough estimate of power usage when benchmarking and gaming with Quad 7970's (Though those were not ghz editions).

    Like JC713 said, heat is a huge concern and power more than anything. Your mimimum requirement would probably be a 1300 watt PSU to handle the full load on CPU and GPUS. Those cards are power hungry especially under load and even a 1300 watt would probably be on the edge based off of what ive seen in vids and a rough estimate based on load power consumption. You also have to take into account the load on the PSU because stressing a PSU on max constantly is not good for it so you have to take that into account as well.
  5. JC713

    JC713 TechSpot Evangelist Posts: 6,810   +884

    red1776 made a Quad SLI 7970 setup, he can help you out. But you first have to get watercooling, motherboard, and PSU requirements out of the way.
  6. red1776

    red1776 Omnipotent Ruler of the Universe Posts: 5,887   +84

    I would not do it with anything less than 1600w/120A. I have three separate PSU's in my setup for a total of 2.2kW/180A, but I am a stickler for the total possible TDP +25% for two reasons.
    1) PSU' hit their peak efficiency around 75-80%
    2) Upgrades
    I have heard that running quad HD 7970's with a Lepa 1600w works well. I would not try to run 4 x 7970 on air though. Vapor cell or not, you will be pushing the bounds of the recommended operating temps of the 7970 (97c)
    @ JC...it's Crossfire man, not SLI...Crossfire. :p ;)
  7. GhostRyder

    GhostRyder TechSpot Evangelist Posts: 2,171   +510

    I'm curious red1776 why do you have that many psu's in your system? What typs of system are you doing that needs that much power? The intrigue is killing me.
  8. red1776

    red1776 Omnipotent Ruler of the Universe Posts: 5,887   +84

    Hey....don't I know you? LOL
    The type of system as you know is a benchmarking , 3 x screen Eyefinity gaming and a 4 x screen productivity setup. The reason for 3 separates PSU' is The Corsair AX1200 (Tektronics build) is a tremendous, single rail, ultra low ripple clean power PSU. It by itself is not enough though. I found these 500w FSP Group PSU's with the same qualities, that I can run off a different circuit. 2.2kW is pushing it for a single wall.
  9. JC713

    JC713 TechSpot Evangelist Posts: 6,810   +884

    Oh man! Thanks for pointing out my SLI mistake. I am just so used to saying SLI not Xfire. That is very funny that you have 3 PSUs lol.
  10. GhostRyder

    GhostRyder TechSpot Evangelist Posts: 2,171   +510

    Ah I see, makes sense then, I was just trying to imagine a couple of builds that would require the power. I run a 3x Eyefinity group as well for gaming on my rig, im running Dual HD 6990's with a rosewill Lightning 1300 PSU to power the whole machine. That corsair my Co-Worker/friend has in his rig right now and its a kick *** PSU from what hes told me and ive seen.

    As for have we met before, im trying to recall, were you speaking on the forums here or somewhere else, if you know me from here oops ive forgotten, im bad with names unless I speak with them on a daily basis so if I did forget, my bad and don't take offence please :p. If it was not from here, then you may know my name from something else possibly, I use this name on every game system and on PC things so maybe there?
  11. death791

    death791 Newcomer, in training Topic Starter Posts: 61

    Thank for the replies and sorry for the late one here is a picture of my current setup http://www.techspot.com/gallery/pc-hardware-modding-pics/p4765-rsz-100-0464.html

    Currently im running 3x 23'' acer monitors at 5760x1080 eyefinity, msi Z77A-GD65 mobo, Intel 3570k i5 cpu, 16gb g.skill sniper 2133 ram, 1050w xfx psu, crossfired xfx 7970 BE video cards, nzxt switch 810 case. im currently saving/working on my watercooling loop. now I planned on switching case, mobo, cpu and power supply before upgrading to either 3 or 4 way 7970 setup. upgrades will be mountain mods case, probably the asus maximus vi extreme or something close to it. cpu will either be the new 4 gen 4770k or 3930k six core, the power supply is really only where im stuck at.
     
  12. JC713

    JC713 TechSpot Evangelist Posts: 6,810   +884

    The CPU is plenty. The problem you have right now, is the case, power supply, and motherboard. The motherboard does not have enough PCIe slots to run quad xfire or even tri xfire. The case you have doesnt have enough of those slots where the rear IO/exhaust of the card is, I forgot what they are called. The PSU cant support power hungry 7970s in quad xfire either. I dont recommend quad xfire since scaling is horrendous. Even nVidia has begun to given up on quad SLI (at least in their advertising/demoes) since they find the scaling to be horrible. At the resolution you are running, tri xfire will be enough. As for the CPU though, dont upgrade from a 3570K to a 4770K. The i5 can handle any game for the next 3-5 years fine. As for the 3930K, that CPU is 2 generations old, and will be refreshed soon. That will be a worthy upgrade since it will gain you better performance due to the extra 2 cores. Plus, the X79 platform is meant for multi GPU configurations.
  13. death791

    death791 Newcomer, in training Topic Starter Posts: 61

    As far as the case and power supply yeah I knew I would have to switch them both, I was thinking about going with the 4770k because im going to have to purchase a mobo that supports both 3 and 4 way xfire, I figured I would go with the new 1150 socket but now that I think about it I can probably get a 4way xfire 1155 board for probably a decent price now I haven't checked on them. For the case I was going to go with a custom mountain mods case with a dual pump/loop 480mm rad for the cards and a 360mm rad for the cpu. I plan on going with 3 way 7970 xfire for sure, so I need one with enough power for atleast that but maybe in the future I would purchase a 4th card so I just wanna get one that will be enough power for then as well. thanks for the help!
  14. GhostRyder

    GhostRyder TechSpot Evangelist Posts: 2,171   +510

    Cool, glad we could help, hope it all works out!
  15. JC713

    JC713 TechSpot Evangelist Posts: 6,810   +884

    This is what you should get:
    Motherboard - You have 5 options:
    http://www.newegg.com/Product/Product.aspx?Item=N82E16813157336 (not sure how well this WS motherboard will work, so I would avoid it).
    http://www.newegg.com/Product/Product.aspx?Item=N82E16813188120
    http://www.newegg.com/Product/Product.aspx?Item=N82E16813157322
    http://www.newegg.com/Product/Product.aspx?Item=N82E16813128569
    http://www.newegg.com/Product/Product.aspx?Item=N82E16813131858
    Power Supply: Corsair AX1200i - 1200W is enough for 3 7970s. In the future, you wont want to buy another 7970 for quad SLI. There will be better technology that will outperform your 3 card configuration with 1 card (2 generations from now - 22nm)
    Case: Any full tower of your choice.
  16. TechGamer

    TechGamer TechSpot Booster Posts: 408   +34

    Jc..... u keep mentioning sli no...................... 7970s go crossfire :D
  17. red1776

    red1776 Omnipotent Ruler of the Universe Posts: 5,887   +84

    Having built a Quadfire machine every nine months or so since 2008, watching it evolve, and having a 4 x 7970 in front of me for 'ultra resolution' gaming and benching I have to disagree slightly with your assessment of the scaling of the fourth card as "horrendous' JC and replace it with 'pretty good'. The 4th 7970 is good for 24 FPS in Heaven 4.0, takes Dirt 3 from 121 to 144 FPS @ 5760 x 1080, is the difference between being able to play Metro 2033 on high or very high @ 5760 x 1080 and the same scenario in other games/benches etc etc.

    As far as the 'bottleneck' issue thrown around by everybody and their dog:
    Heaven 4.0 @ 1920 x 1080 - AMD FX-8350 & (4 x HD 7970 GHz Ed)
    [​IMG]

    [​IMG]

    [​IMG]

    BF3 @ 5760 x 1080 Highest settings - AMD FX-8350 & (4 x HD 7970 GHz Ed)

    There was most definitely a time when running 4 GPUs was somewhere between a lousy to non-existent ROI, however if you are running graphic benchmarks, multiple screen setups and like the graphics turned up, running a fourth GPU is essential.
    Hope that helps clear some things up death. If you would like some more info or game/bench graphs just give me a holler.
    JC713 and GhostRyder like this.
  18. LNCPapa

    LNCPapa TS Special Forces Posts: 4,287   +262

    :sending red a bowl full of drool:

    Thanks for making my BeefyArm seem inadequate (that's the name of my gaming machine)
    Darth Shiv likes this.
  19. Blkfx1

    Blkfx1 TechSpot Addict Posts: 884   +171

    Lol, don't feel bad. A Lot of us are in the same boat lol.
  20. GhostRyder

    GhostRyder TechSpot Evangelist Posts: 2,171   +510

    Red1776, Your are the best, im so following you now! Yea even though im running dual GPU cards, have 4 GPU's is the bomb.

    Never knew having multiple cards was so much fun till I tried it.
  21. JC713

    JC713 TechSpot Evangelist Posts: 6,810   +884

    Well, quad SLI doesnt scale well. xfire on the other hand, may be different.
  22. red1776

    red1776 Omnipotent Ruler of the Universe Posts: 5,887   +84

    Yeah Nvidia has quietly let quad SLI go bye -bye, or at least not be promoted. It does okay in some benchmarks, but benchmarks like Heaven, 3DMark11 and the like are designed to give you full credit for all the hardware you have on board. Things change substantially when you switch to actual games.
  23. GhostRyder

    GhostRyder TechSpot Evangelist Posts: 2,171   +510

    Even on the nvidia site they don't say their 80 series of cards (ie the gtx 780 or 680) supports quad where as the dual gpu ones can. Odd because I swear it's possible because I've seen systems with them.

    JC713 that's why I personally like amd cards better now. Tri and quad is a lot easier to manage IMHO and just comes ready for extreme setups. It gets some odd results when going tri and quad setups on the amd cards. Let me see if I can find the review I was thinking of and post it, but tons hardware had an odd result that I found interesting.
  24. JC713

    JC713 TechSpot Evangelist Posts: 6,810   +884

    It is possible, but nVidia doesnt advertise it since scaling is bad and they dont want to optimize it. Tri and quad xfire setups are definitely improving with AMD.
  25. dividebyzero

    dividebyzero trainee n00b Posts: 4,815   +646

    The issue with quad-SLI is generally down to the need to qualify the platform with the cards from what I understand, which in turn stems from Nvidia's edict that SLI can be enabled only by x16 or x8 lane connectivity and the load balancing requirement for Nvidia's QA.
    Most boards (at least full sized non-budget chipsets) sport at least a single x16 PCI-E and a secondary x8 slot which reduces the primary to x8 also (if populated). Thus 2 card, whether they be single or dual GPU, SLI is widespread. Other chipsets generally rely on PLX bridge chip / lane extender solutions which, depending upon the board vendor may or may not support four card SLI. Depends if one (or more) the split lanes reduce down to x4 if all the slots are populated, or (more likely), that bandwidth is shared with eSATA, SATA 6GB, or USB3.0.

    Because of the variations in boards and the various QA permutations required, Nvidia don't make the blanket statement of a certain card being quad SLI capable, even though its widely known that the cards support the feature. The GTX 670 at launch was tri-SLI (max) supported as Nvidia thought that anyone looking at quad-SLI would be buying GTX 680's. Once the buying public realized -in short order- that four 4GB GTX 670's could be had for the same/lower price as 2GB GTX 680's, the official support was built into the driver.
    JC713 likes this.


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