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Sapphire Radeon HD 7790 Dual-X Pictured, Tested

Discussion in 'News' started by btarunr, Mar 16, 2013.

  1. _Zod_ New Member

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    I think you misunderstand what he's saying. The 6790 was 256 bit while this, which by model number would be it's successor is only 128 bit. But can bet this will destroy the 6790 even with the bandwidth crunch.
  2. MxPhenom 216

    MxPhenom 216 Corsair Fanboy

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    Nice looking card too.
  3. Aquinus

    Aquinus Resident Wat-man

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    256-bit GDDR5 might have been overly wasteful on the 6790. Just because you give a GPU more bandwidth doesn't mean it can use it. Keep in mind that when you add bandwidth this way, you're only making memory access wider, not faster. So if all the data can fit in 128-bit at a given clock, there is no reason to have 256-bit memory. It could be a waste of money, space, and time. Something AMD can no longer afford.
  4. blibba

    blibba

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    All true, but I think in the case of the 6790 the available silicon was all running fine as 256-bit and there was no extra cost to leaving it that way.
  5. Casecutter

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    While no different for if Nvidia... GTS 250 was 256-bit ... GTS 450 on 128-Bit ... GTX 550Ti on 192 ... and then a GTX 650Ti on 128-Bit; while if rumors hold true Nvidia will release a GTX 650Ti Boost with 192-Bit.

    Changes in memory bus width have never been a tried and true designator for a given class of cards.

    Given the 6970 was just a gelded 6850 (Barts with less Sp) AMD used the same PCB as a way of holding down cost, while able to raise core/memory clocks with the same power section. While no one can afford a more complex PCB it can be a big sales draw... As with what Nvidia intends with the alleged GTX 650 Boost. They look to run it on 192-bit to unbridle it from what they want you to believe is bandwidth starve 128-Bit. While is it just more a selling feature, than actually what a 768 Sp part can truly saturate?

    I see it as GTX650 (GK107) has 2 SMX 128-Bit, while a GTX650Ti (GK106) has 3 SMX 128-bit and speeding the memory to 100Gb/s does assist about 10%. Then contemplate they provided a huge (68%) jump it bandwidth GTX660 (GK106) 5 SMX 192-Bit 144Gb/s, and between them there’s a jump (60%) in performance, but what's it from 2 extra SMX or bandwidth being used by those 2 extra SMX? While the GTX660Ti on GK104 with 7 SMX can do with 192-Bit. I just wonder will a 3 SMX part overwhelm anything much over 110Gb/s?
    Last edited: Mar 18, 2013
  6. tokyoduong

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    Guys stop worrying about bus width lol.

    The numbering starts with architecture that sets different performance. Then to fill in gaps of performance they are forced to use other architectures because of design limitations. It's confusing when you know the technical details but to an average consumer who just want a performance metric then this makes logical sense.
  7. Casecutter

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    Sorry friend in this particular case $125-150 price I don't worry if it has only a 2-Y warranty, sure for a 7990 or 7970 warranty maters but not the time/place to grind that argument. Although you are awere PowerColor Devil 13 does have a 3-Year (Three Skulls) …
    Other than return shipping neither of the two cards I've had to return for manufacture warranty have cost me a cent (EVGA/PowerColor). Not sure where you live or why you'd have to spend $50 to get a direct replacement. While XFX not all their card will have Lifetime anymore only certain models provide that.

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