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Boost, Overclocking, And CrossFire

Tahiti LE, Tested: PowerColor's HD7870 PCS+ Myst Edition
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Clock Frequencies at Partial and Full Load

PowerColor's HD7870 PCS+ Myst Edition is pegged at its 925 MHz base clock rate when you push the Tahiti LE GPU really hard using general-purpose computing workloads. Games tend to be less taxing, giving the board some headroom to spend time at its 975 MHz Boost frequency. The higher clock rate isn't very consistent, though, particularly as you play through more demanding titles at higher detail settings.

Overclocking

Depending on your card and the rest of your system components, overclocking PowerColor's HD7870 PCS+ Myst Edition can increase its performance by 15% or more. We pushed the card's core clock all the way up to 1.2 GHz without touching its voltage. Setting PowerTune to +20% is all that it took to achieve a stable overclock.

This is pretty consistent with what we've seen from Radeon HD 7900-series cards. Our Pitcairn-based Radeon HD 7870 only makes it to 1,150 MHz.

There’s not much room to overclock the HD7870 PCS+ Myst Edition’s memory, though. We pushed it to exactly 1,600 MHz. Increasing the voltage is not a good idea, since the un-cooled RAM gets too hot. Besides, a 1,500 MHz factory setting is enough to prevent bandwidth bottlenecks from negatively influencing frame rates. If you care about the card's longevity, it’s better to just leave the memory frequency be.

CrossFire

PowerColor's HD7870 PCS+ Myst Edition shows its Tahiti roots when it comes to CrossFire configurations; you cannot pair it up to a normal Radeon HD 7870. Matching it up to any Radeon HD 7900-series card isn't a problem, though. In fact, we installed our review sample next to a HIS 7950 X², and we matched the performance level of the two cards by overclocking the PowerColor HD7870 PCS+ Myst Edition to 1.15 GHz. This gets us close to the same single-frame rendering times. However, if you leave both cards at their factory-set frequencies, you'll see a lot of micro-stuttering. Even RadeonPro couldn’t alleviate the issue, leaving us with dropped frames.

At $240 per card, two PowerColor HD7870 PCS+ Myst Edition boards make for a very competitive high-performance setup for less than $500. Now, let's take a look at power consumption.

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Top Comments
  • 26 Hide
    EzioAs , February 11, 2013 3:28 AM
    Quote:
    If it cant CFX with a 78xx, it has no right to be called a 7870+ . Marketing name fail +1.


    I agree. AMD has already establish good model naming scheme (X900 for high-end gaming, X800 for mid-range, X700 for low end gaming) after the 6000 series. To be honest, I say it's stupid not to call this chip the HD7930.
  • 23 Hide
    mayankleoboy1 , February 11, 2013 3:22 AM
    Isnt this review quite a bit late ? IIRC, the card came ~1.5 months back...

    If it cant CFX with a 78xx, it has no right to be called a 7870+ . Marketing name fail +1.
    The chip by itself is fine, though.
  • 16 Hide
    EzioAs , February 11, 2013 3:25 AM
    That's quite a short review. It's not anything I haven't looked at other sites. Anyway, at the current price, I really have to agree the 7870XT (Tahiti LE) are excellent cards.
Other Comments
  • 23 Hide
    mayankleoboy1 , February 11, 2013 3:22 AM
    Isnt this review quite a bit late ? IIRC, the card came ~1.5 months back...

    If it cant CFX with a 78xx, it has no right to be called a 7870+ . Marketing name fail +1.
    The chip by itself is fine, though.
  • 16 Hide
    EzioAs , February 11, 2013 3:25 AM
    That's quite a short review. It's not anything I haven't looked at other sites. Anyway, at the current price, I really have to agree the 7870XT (Tahiti LE) are excellent cards.
  • 26 Hide
    EzioAs , February 11, 2013 3:28 AM
    Quote:
    If it cant CFX with a 78xx, it has no right to be called a 7870+ . Marketing name fail +1.


    I agree. AMD has already establish good model naming scheme (X900 for high-end gaming, X800 for mid-range, X700 for low end gaming) after the 6000 series. To be honest, I say it's stupid not to call this chip the HD7930.
  • 13 Hide
    Azn Cracker , February 11, 2013 3:48 AM
    Or maybe the 7950 LE since its pretty much the same card just slower.
  • 7 Hide
    hero1 , February 11, 2013 4:06 AM
    Azn CrackerOr maybe the 7950 LE since its pretty much the same card just slower.


    I agree with you on this one. Someone need to give these guys a call and tell them how it is. What a load of bs on their naming scheme. I would absolutely call this 7950 SS or LE!
  • 7 Hide
    Anonymous , February 11, 2013 4:11 AM
    where are the frame time benches?
  • 7 Hide
    FormatC , February 11, 2013 4:19 AM
    The frametime thing (in some games) was gone (more or less) with the latest drivers and I think that AMD will handle the memory now a little bit better ;) 
  • 3 Hide
    shikamaru31789 , February 11, 2013 4:27 AM
    If only some other manufacturers were making these, Power Color's cooling solution isn't that good, 37.8 decibels while Gaming is not quiet enough for me.
  • 8 Hide
    EzioAs , February 11, 2013 4:30 AM
    Quote:
    If only some other manufacturers were making these, Power Color's cooling solution isn't that good, 37.8 decibels while Gaming is not quiet enough for me.


    Sapphire has one too, I believe
  • 6 Hide
    shikamaru31789 , February 11, 2013 4:42 AM
    EzioAsSapphire has one too, I believe

    Yeah, I just now noticed it on Newegg. Not sure why I didn't notice it before, based on the reviews it's been on there awhile. Too bad it costs $20 more than Power Color's. Still a good deal even at $260, since this review indicates that it's almost as fast as the much more expensive 7950's.
  • 13 Hide
    FormatC , February 11, 2013 4:45 AM
    It makes sense to include the frametimes if I can show something abormal. If the result is as expected in the tested games... The article was written in the begin of December and published in German first and we all knows what AMD answered about the frametime problems. I'm always using the frametime analysis to proof my benchmark results.

    BTW:
    The Powercolor card was tested a little bit later due the new BIOS. Powercolor has stopped the launch to correct some problems (Club3D and VTX3D were delivered with older BIOSes)
  • 8 Hide
    ricardok , February 11, 2013 5:13 AM
    And please, don't forget to add the Catalyst version you guys are using..

    This time we are without that info. And please say that you did the test with the newest driver.. I fail to see why you guys kept testing with 12.10..
  • 3 Hide
    iam2thecrowe , February 11, 2013 6:18 AM
    should be 7950 Le (light edition). But good card.
  • 4 Hide
    The_Trutherizer , February 11, 2013 6:31 AM
    shikamaru31789If only some other manufacturers were making these, Power Color's cooling solution isn't that good, 37.8 decibels while Gaming is not quiet enough for me.


    I remember about 10-5 years ago 40 decibels was considered whisper quiet.
  • 4 Hide
    JJ1217 , February 11, 2013 7:49 AM
    shikamaru31789Yeah, I just now noticed it on Newegg. Not sure why I didn't notice it before, based on the reviews it's been on there awhile. Too bad it costs $20 more than Power Color's. Still a good deal even at $260, since this review indicates that it's almost as fast as the much more expensive 7950's.


    ehh? I grabbed a Asus 7950 for $230 in *Australia* brand new... I think they're trying to get rid of them since it was the faulty model (Which is easily fixable and since been replaced by the V2 version)..
  • 5 Hide
    sanilmahambre , February 11, 2013 9:02 AM
    SAPPHIRE should have manufactured these Tahiti LE cards with VaporX cooler
  • 2 Hide
    iceclock , February 11, 2013 9:39 AM
    very nice article, at the moment i find the 7870xt edition is one of the best bang for bucks card atm.

    since it gives a good performance for lower cost than 7950 or 660ti

  • 7 Hide
    Anonymous , February 11, 2013 12:20 PM
    I don't understand the conclusion's comments: "if you cannot afford a real 660 Ti this is an alternative." Your benchmarks show this card AHEAD of the 660 Ti in average performance and individual performances, so this card is a better deal even if they cost exactly the same!
  • 4 Hide
    nokiddingboss , February 11, 2013 12:47 PM
    great card but it should have been named 7950 LE. they sure do know how to confuse customers.
  • 5 Hide
    Anonymous , February 11, 2013 1:56 PM
    Id highly suggest buying this baby on NEWEGG as you get BIOSHOCK/TOMB RAIDER Games BUNDLED or BIOSHOCK/CRYSIS 3 BUNDLED for FREE. I'm also under the impression you get the boxed versions.

    Plop these baby's on ebay/amazon and your looking at a 7930-LE $240 for only $140
    DAAANNNG. ^_^
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