R9 280X - which ones are voltage unlocked?

Discussion in 'AMD Flavor' started by wyqtor, Nov 25, 2013.

  1. wyqtor

    wyqtor Limp Gawd

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    I would like to buy a R9 280X that is voltage unlocked so I can undervolt it for max efficiency while mining litecoins and to make its power consumption fit my 650 W PSU better (I will be using it in XFire with my 7950). I would preferably like one with the best cooling, for my peace of mind.

    On the web I read conflicting reports, I was just about to pull the trigger on a Sapphire Toxic R9 280X until I read that it might be locked (WTF Sapphire? I thought this was your highest-end model? Even my lowly 7950 Dual-X Boost is unlocked). Flashing BIOSes to unlock them is also something I would just rather not do. I really wanted the Toxic because I could also get closer to GeForce 780 performance while playing games not supporting XFire, or unleash its full power after I upgraded to a 850 W PSU.
     
  2. Croak

    Croak [H]ard|Gawd

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    Asus Matrix Platinum 280X is totally unlocked and undervolts quite well (I have two in 7970 guise running the 280X BIOS, and I used to underclock and undervolt to keep fan noise and temps down in extended gameplay until I got my new board with better slot spacing, and a better case).

    Even at stock 1100/1600 clocks it'll volt down to 1.188v core, 1.55v RAM. Downside is that big ass three-slot cooler, I had to buy a Maximus V Extreme just to get enough slot spacing for two cards that didn't cook the top card in Crossfire. You can also diddle with VDDCi power and LLC to drop volts (higher LLC increases power usage but drops temps, go figure), and drop down to 90% power target without any throttling.

    Overclocking is a bit of a problem though, even in single card installations the RAM is already running within an inch of its life out of the box for most owners, some can't even keep it stable with the default 1600 RAM speed and have to underclock down to GE speeds (1500), while a very few (and all the reviewer samples, it seems) can bump up to 1700 or more.

    All that said, now that I've got the cooling sorted, dialed in a good custom fan profile with the Asus GPU Tweak software, I'm able to run mine stable at 1200v @1.25v and VRAM at 1600 @1.55v, never exceeding my personal target of 85c on the top card after hours of Valley Benchmark Ultra/8x AA stress testing, and never cracking much over 70c in Ultra BF4 sans FXAA, both at 1440p.

    Overall I'm very happy with the cards, especially considering I bought them on sale for €100 less each than the 280X version (same card) was selling for, and with the overclock they're not that far behind a 290, and a helluva lot less noisy. :)
     
  3. wyqtor

    wyqtor Limp Gawd

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    Unfortunately, Asus cards are very expensive where I live, the Matrix Platinum is close to R9 290 in pricing. I will probably go with either Sapphire Toxic or Vapor-X, but I need a confirmation that one or the other is voltage unlocked. Anyone?
     
  4. Decimus

    Decimus [H]ard|Gawd

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    According to my box the XFX DD 280x are voltage unlocked. I haven't had time to play around and make sure that it is true though.
     
  5. XFXSupport

    XFXSupport XFX Representative

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    Greetings,

    I can confirm that all of our 280x are voltage-unlocked.

    -Please download the latest updates for your tuning software.

    Play Hard!