CFX/mGPU gaming on Vegas anno 2020. Any good?

Discussion in 'Videocards - AMD Radeon Drivers Section' started by Dekaohtoura, Feb 8, 2020.

  1. Dekaohtoura

    Dekaohtoura Master Guru

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    I hope the title is self explanatory.

    Vega 56/64 officially support CF, though actual support is a bit of a guess-game.

    Since used Vegas are pretty cheap atm, I thought I could pair my V56 Pulse (Samsung mem) with another V56 (preferably, if I can find one with Samsung HBM also) and wait till the first real Navi cards (afaik RX5700s is a hybrid generation) get rid of any early illnesses etc.

    I'm gaming on a 1440p/144Hz/FS monitor, so I could really benefit from the extra power.

    Looking around on the net, I found out that most DX12 titles are compatible(-ish) with mGPU setups and that there is a pretty good scaling, usually.

    Is there something that should completely discourage me?

    I have a Corsair D800 tower to house them, a 850W gold Seasonic PSU, a R1700@3.8 on a X370 Taichi.

    Any input will be appreciated.

    TY!
     
  2. Dekaohtoura

    Dekaohtoura Master Guru

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    Really?

    Noone uses CFX anymore?
     
  3. dexterav

    dexterav Master Guru

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    its allway about few user ,1-2% at the best
    and be honest booth AMD/NV just simple drop mgpu to grave
    maybe in time return
     
  4. bobblunderton

    bobblunderton Master Guru

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    DO NOT use multi-GPU setups, unless you only play one game and it is proven to support it well without issue.
    You'd have better luck overclocking the snot out of one of those VEGA GPU's.
    Even 10 years ago they were a pain in the butt, and it's only gotten worse over time for multi-GPU rendering.
     

  5. Dekaohtoura

    Dekaohtoura Master Guru

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    I know it's uncommon, to say the least, but I was expecting one or two answers from some hc testers.

    Ten years ago I went from a single 5770 to CFX...best decision ever. Scaling >90% on almost every game I tried (BF3 was great!).

    Had to give them away, at some point, since my PSU (Corsair, RM550) was right on the edge.
     
  6. bobblunderton

    bobblunderton Master Guru

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    Well, consider one's self lucky. I myself had a 7950 GX/2 (sli on a single card) in 2006 and by 2008 or 2009 had a GTX 260 XXX B E Sli. They worked great when they worked - your only hope on getting 60fps or close to it on high settings in a game like New Vegas at 1920 x 1200.

    It WAS great when it worked back then. When it didn't have flickering, crashing / BSOD's, or artifacting/slowdown/etc issues. It was much better supported at the time 10 years ago than it is today, is what myself and another are trying to say.

    In other words, do read up on some recent SLI / X-fire benchmarks. WHEN it's supported, it's a great thing, and an even better space heater. I am sure you can cook an entire holiday meal in 30 minutes - even with the in-laws coming - on a pair of overclocked Vega's (not so much a joke when you OC Vega!).
    SO, you COULD spend 100~250$ procuring another VEGA card (from lower end Vega 56 reference models just over 100$, to higher-end Vega 64 models at around 200~250$)... and HOPE that it works in what you're running it with, on your specific system configuration.
    OR...
    You could SELL your existing VEGA 56 card for 100~150$, and buy a 300~400$ and be, in the end, out ABOUT the same 150~250$ or so, and use a LOT less power and generate a LOT less heat in the long run. You'll also have a much quieter PC, too. You will rarely if ever have to worry about application/game supporting a SINGLE video card solution for rendering, and you'll rarely find yourself fighting off bugs making games unplayable or strange crashes in the same vain.

    SLI / Crossfire was GREAT when it was supported well, but the writing's on the wall, and it's BEEN for years, and mostly only top-end cards support it these days. With top end cards being powerful enough to push most instances of running a game well beyond 60FPS, there's not much NEED to go SLI or Crossfire, though some people may still WANT it. It becomes less of an issue when 'I want' doesn't work VS when an 'I NEED' doesn't work.

    So, with that out of the way, if you still want to do it, for whatever reason, do this.
    Get another (for ex. Red Devil Vega 56/64 card, as those have MEGA VRM solutions) Vega card, non-reference design.
    Overclock the snot out of it, and stick the faster of the two cards in the top primary GPU PCI-E slot.
    Put the lesser clocking one in the lower, secondary x4 or prefferably x8 slot (only makes a FEW FPS difference, if that, between x4 and x8 on PCI-E 3.0).
    This way, you can run nominal clocks on both cards, that both will run stable at, and not exceed and 850w power supply's capability, when running Xfire.
    When you run single-card mode, you can clock the card to the hill, use 500w of power just on ONE GPU, and have almost the power of a RTX 2070... IF you get a really GOOD clocking card. There's a reason those RED DEVIL cards go for so much money used, though, so DO weigh the value/risk.
    Keep in mind the EVGA RTX 2060 KO is 300$ or so, so don't spend too much on X-fire that only sometimes might work - and it's never promised - VS spending good money on something YOU KNOW will almost ALWAYS work sans a completely broken game here or there (not entirely unheard of).
    I am just trying to save you some pain. It's not talking down to you at all, or it's not SUPPOSED to be, BUT, you do have to regularly engage in self-loathing if you want to try X-fire or SLI these days...
    --Good luck!
     
  7. Dekaohtoura

    Dekaohtoura Master Guru

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    @bobblunderton

    TY, I think... :p

    Most of the games I usually play, seem to really benefit from CFX (BFV, NFS...Frostbyte engine mainly).

    I may give it a go should I find a used V56/64 at a decent price+condition, to bridge the "gap" until Navi2/Ampere.

    Power wise, you're exaggerating a bit...my V56 (64 vbios) with uv+oc needs <230W while gaming and around 250 on heavy benches (this, on my 24/7 profile).

    With 2 cards, I won't even need to oc the core (only the memory) and I bet I can go as low as 1060mV (<200W peak).

    Anyway, it's just an "impulse", not a need (though 2xV56 >>2080Ti if scaling is anywhere >85%). If I bite the bullet, I'll let you know.
     
  8. bobblunderton

    bobblunderton Master Guru

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    Gamer's Nexus did an overclock of a Power Color Red Devil 56 and it got up to 500 watts, though they got RTX 2070 speeds out of it, or there-about.
    Do look up the video on it on youtube, at some point, it's pretty interesting. That was just ONE card. So if you have the cooling, and the power, you may just be able to hold yourself over with ONE good OC'ed card.
    I get the impulse thing, I do, I used to be like that. Maybe sometimes better to just save up money for one good one so that next time you get into the next great game or application that DOESN'T support SLI/X-fire that well, you wouldn't be up the creek without a paddle then.
    I mean, in the end it's your money, your time, your machine (etc), so I can't force you to do something (and won't). If your favorite apps support it, great, but just go in knowing that it (SLI/X-fire support) is more the exception, than the rule.
     
    Dekaohtoura likes this.

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