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Another HD 6870 for Crossfire or HD 7870?

Discussion in 'AMD / ATI' started by MaxAwesome, Mar 16, 2012.

  1. MaxAwesome

    MaxAwesome

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    Hi guys.

    I'm thinking of getting more GPU power on my system.

    I'm either considering adding another HD 6870 and do crossfire or sell and get an HD 7870.

    I've never used multi-GPUs before, because I've read about microstuttering and whatnot, so I've always preferred a powerful single GPU rather than 2.

    My question is: How stable is crossfire for the HD 6870? I know they scale really well, but what about stability?

    I can find HD 6870s for sale second-hand, for really cheap and they would be more powerful than a single 7870.

    What do you guys think?

    CFX users, please chime in!
  2. erocker

    erocker Super Moderator Staff Member

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    Since it's cheaper go for the CrossFire. If you end up not liking it go with a more powerful single GPU. Everyone seems to have different experiences with CrossFire setups.
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  3. MaxAwesome

    MaxAwesome

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    Makes sense ;)

    And what about configuring a CFX setup? Is it straight forward?

    I'm a bit clueless when it comes to multi-GPU systems. Would I need a CF bridge? Does it work without it? Are there performance differences?

    My main issue with it, is game compatibility. I know all major new releases support it, but does CFX get activated automatically or do I have to fiddle with the driver settings for each game?
  4. HossHuge

    HossHuge

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    And what about configuring a CFX setup? Is it straight forward? Yup. Install the new card and CCC will configure it. You will see new options in CCC.
    I'm a bit clueless when it comes to multi-GPU systems. Would I need a CF bridge? Yes Does it work without it? Yes, but only if you want to use more than one monitor. Are there performance differences? 68XX series cards scale really well.
    My main issue with it, is game compatibility. I know all major new releases support it, but does CFX get activated automatically or do I have to fiddle with the driver settings for each game? You will need to download and install the additional AMD Catalyst Application Profiles.
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  5. erocker

    erocker Super Moderator Staff Member

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    I'm not sure it will work without the bridge. It straight up told me I need to connect a bridge in CCC with my 6950's. It might work just installing the card on current drivers... Might not though.
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  6. HossHuge

    HossHuge

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    You are right. What I meant to say is that you can use it without the crossfire bridge if you want to install lots o monitors. But if you want to use them together for one game, you will need the bridge.
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  7. Shinj New Member

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    If you plan to go for a crossfire setup, you must be prepared to face some micro stuttering issues. This issue exist because now you're rendering frames using two GPU and delay exist between the interconnection. Thus, there will be a short time interval between the arrival of each frames and to human eyes, it is perceived at stutter.

    This article from Tom's Hardware outline the issue in detail, and the good thing is, they use single 6870, 6870 in crossfire and 6870x2 as examples, which will help in your decision making I believe.

    http://www.tomshardware.com/reviews/radeon-geforce-stutter-crossfire,2995-3.html
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  8. DarkOCean

    DarkOCean

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    If 1gb vram its enough for you then go for it if no it's time for a new gpu.
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  9. MaxAwesome

    MaxAwesome

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    That's the main reason I'm considering the HD 7870. My monitor is a 22" LG Widescreen full HD monitor.

    In the long run, 1GB might not cut it for 1080p. Maybe I should go with a single 2gb HD 7870 after all :)
  10. Aquinus

    Aquinus Resident Wat-man

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    I have two 6870s on my LGA2011 platform and it runs extremely well. I do notice a little bit of micro-stuttering but optimizing your application profiles, cpu, and memory will either mitigate the issue substantially, make it hardly noticeable, or in some applications eliminate it all together. I have yet to find a game that it cannot handle at at least 60fps @ 1920x1200 and I'm very happy with my investment and I have to say, it runs pretty well. The micro-stuttering is less of a stutter as it feels more tearing when v-sync is disabled (even though it is enabled). Changing the crossfire mode may eliminate this, I haven't played around with it enough to say. The only issue I've run into is HDR reflections on Crysis 2, which I'm sure have been fixed in later version of it, I'm still running the retail version, no updates.
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  11. MaxAwesome

    MaxAwesome

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    Well, that's what I feared. I'm probably going to keep using single GPU, might go with the HD 7870 for a nice performance bump with less hassle :)
  12. FreedomEclipse

    FreedomEclipse Crazy Dogmatic Bullsh!t!

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    +1

    Be aware of shoddy drivers from AMD, their drivers havent been very good as of late but its mainly when a new games released then its a major rush for them to throw out buggy drivers that require loads of hotfix updates before they start working at a suitable level.
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  13. HossHuge

    HossHuge

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    The only time I notice micro-stutter is in fast paced games such as car racing games. I've never noticed it, whatsoever, in any other style game.
  14. m1dg3t

    m1dg3t

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    According to this http://www.gpureview.com/show_cards.php?card1=635&card2=677# 6870 CF (you need to select option for multi GPU) is almost DBL performance of single 7870 with ~125w more draw, it may be best to go CF for now (if PSU can handle it) until better pricing arrives on the newer gen card's. I have never used CF or multi GPU for that matter, always ran highest single GPU budget allow's :eek:
  15. Shinj New Member

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    Yeah, it's definitely true that AMD driver is sometime problematic. However, when it work, it ran wonderfully. The scaling of 6000 series and above is so good that you can almost guarantee 2x performance in all the latest games except recently release titles.

    The only thing to worry for the 6870 CFX is that the amount of memory is limited to 1GB, even though you will be running two cards with 1GB each. It might not cut it for the latest games with full details, full AA and Eyefinity multi monitors gaming any more. That's the reason to choose a HD7870 over the crossfire setup.
  16. Artas1984

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    Definitely CrossFire HD6870. - cheaper and faster.
  17. MaxAwesome

    MaxAwesome

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    I know, but in the long run, I'm a bit worried 1GB VRAM won't be enough. That's why i'm more inclined to get the HD 7870.
  18. Aquinus

    Aquinus Resident Wat-man

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    For the same price you could consider a 6870 X2 for triple crossfire, but I wouldn't call that practical. I do hear that micro-stutter is much less of a problem going down this route but support for it is another issue as well.
  19. Evolved

    Evolved New Member

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    Crossfire isn't worth the hype.

    I've learned from experience.
  20. Aquinus

    Aquinus Resident Wat-man

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    It works fine for me...
  21. CrackerJack

    CrackerJack

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    I love my Crossfire 6870's!
  22. Artas1984

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    It's -know your game. For example i have tested and learned that in Necrovision a HD4870X2 matches the HD6970 while in Far Cry 2 it is even weaker than a HD6850..

    In general 2X HD6870 will give over 2200 shaders clocked at 900 MHz - if scaling will be anything like in Necrovison, CrossFire HD6870 will match HD7970.
  23. Evolved

    Evolved New Member

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    Crossfire works fine. That's not the problem. The problem is the performance versus a single powerful card.

    I find that a single HD 7970 is performing much, much better than my previous two EAH 6870's.

    Despite the benchmarks of HD 6870's being higher than a single HD 7970.

    I don't know... maybe it's just me. :)
  24. Fourstaff

    Fourstaff Moderator Staff Member

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    To answer whether the 1GB VRAM is going to be enough, it depends on how long do you intend to run the CF setup. I can see that its going to be enough for the next year, maybe another year after that. You will have to slowly scale back the details as time goes on, but whether you will need to scale back faster than a 2GB 7870 depends on what they game producers are coming up with over the next two years. I have a suspicion 1GB VRAM will be enough for most games which are not aiming for best detail category until PS4/Xbox720/WiiYouMe gets announced/released.
  25. marek100

    marek100 New Member

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    Bump,

    Sorry for the bump but i need to ask you guys some more info about HD 6870 in CF,
    1. The total memory ? it is 1GB with two cards or its 2GB?

    2.what drivers most of you (HD6870 in CF users ) use now ? i have 12.3 and for some strange reasons games runs like S****t

    Well maybe i will say more about my system :
    Motherboard:Asus M5A97 PRO 970
    CPU: AMD FX-4 4100 Black Edition , OC,d to 4.2 GHz
    RAM: Patriot Signature DDR3 8GB 1333MHz
    GPU: Sapphire HD 6870 Toxic (two of them in CF)
    PSU: Corsair HX750W
    22" screen
    after reading lots of info about CF 6870 i can't work out why my games runs like crap. IE: BF3 @ 30-60 FPS max (game settings at max no ultra) and so on , when i was using only one video card i was getting avr. 50-80 FPS in BF3 same settings. So i have a question about what drivers to use with CF ? or maybe its some ather reason why i getting so low FPS with CF config? just please don't go about FX 4100 , yes i knew its S***t , ill buy 8150 next month for sure.

    thanks , Mark

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