Meet The Radeon HD 7790 & Sapphire HD 7790 Dual-X Turbo

Today we’ll be looking at two cards, AMD’s reference card and Sapphire’s customized HD 7790 Dual-X OC. As is typical for cards in this price segment, the designs are relatively simple and as such only a few partners will be using the reference design as opposed to rolling their own designs. At the same time AMD is pushing their partners’ factory overclocked cards hard – we have the Sapphire and then 3 more on their way – but it’s important to keep in mind that not every last 7790 will be factory overclocked. So AMD’s Spartan reference card is a good example of baseline 7790 performance will be like, including how well it performs with a simple, single-fan open air cooler.

As we alluded to a moment ago, AMD’s reference 7790 is a spartan card. At under 7” long it’s actually shorter than the 7770 and has more in common with the 7750 as far as board length goes. Cooling is provided by a small open air cooler, composed of a circular heatsink with copper heatpipes running up from the base of the card and into the heatsink fins. At the center is a single, small fan responsible for providing the airflow for the card. Meanwhile towards the front of the card we find a small upright heatsink, providing the minimal cooling necessary for the MOSFETs regulating power for the card.

As we’re looking at a 128bit card, memory is provided by 4 6GHz Hynix GDDR5 memory modules, placed on the front of the card underneath the heatsink. A lot of AMD’s partners will be shipping their cards with the memory overclocked to 6.4GHz, which is a fairly common overclock for Hynix’s GDDR5 modules these days.

Elsewhere on the card we can see the sole 6pin PCIe power socket, pointing towards the rear of the card. The 7790 does draw more power than the 7770, and while total power consumption is fairly low, it’s still over 75W and hence requires external power. Meanwhile at the top of the card we can see a single CrossFire connector. AMD believes offering CF here when NVIDIA’s closest product doesn’t (the GTX 650 Ti) is a marketable advantage, but CFing a 1GB card in 2013 strikes us as a poor idea.

Finally, for display connectivity AMD has deviated from the rest of the 7000 series a bit. The 7700 and 7800 series used a single row of display connectors, typically composed of an HDMI port, a DL-DVI-I port, and 2 miniDPs. With 7790 however AMD is dropping the miniDPs in favor of one full-size DisplayPort, and at the same time they’re bringing back the stacked DVI connector. 

Taking up space on the 2nd slot of the card’s bracket is a DL-DVI-D port, giving us the first AMD card with two DVI ports in this price range in some time. Note that while Bonaire can drive up to 6 displays it can only drive 2 TMDS-type displays (DVI/HDMI), so the second DVI port can only be used if the HDMI port is not in use.

Radeon HD 7790 Specification Comparison
  Radeon HD 7790 (Ref) Sapphhire HD 7790 OC
Base Clock 1000MHz 1075MHz
Memory Clock 6GHz 6.4GHz
Frame Buffer 1GB 1GB
Width Double Slot Double Slot
Length N/A N/A
Warranty N/A 2 Year
Price Point $149 $159

Meet The Sapphire HD 7790 Dual-X OC

Moving on, we’re also taking a look at a partner card today, Sapphire’s HD 7790 Dual-X OC. Virtually every partner is releasing a factory overclocked card of some kind with their own take on the design, but Sapphire’s 7790 should be a good representation of what to expect given how similar many of the 7790 designs are.

To that end Sapphire’s Dual-X cooler is your fairly standard twin fan design, utilizing a pair of shallow fans mounted over an aluminum heatsink that runs over the length of the card. A pair of copper heatpipes run from the baseplate over the GPU to the heatsink, with the entire solution serving as an open-air cooler. Note that while Sapphire is using AMD’s reference PC design here, they have lengthened their PCB to match the length of their heatsink, and to allow them to turn the PCIe socket 90 degrees so that it now is against the top of the card rather than the rear.

As given away by the OC name, Sapphire will be shipping their card with a decent factory overclock. Shipping speeds will be 1075MHz for the core and 6.4GHz for the memory, a 7.5% core overclock and 6.5% memory overclock respectively. This will be the most common factory overclock, with several other partners shipping their top-end cards with the same overclock.

Other than the custom cooler and factory overclock, Sapphire’s card is otherwise functionally identical to AMD’s reference card. We’re looking at the same display output configuration of 1x DP, 1x HDMI, and 2x DL-DVI, with the same CrossFire capabilities. Sapphire is putting the MSRP of the card at $159, putting a $10 premium on their cooler and factory overclock.

The New PowerTune: Adding Further States The Test
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  • GivMe1 - Friday, March 22, 2013 - link

    128bit interface is going to hurt high res textures... Reply
  • CeriseCogburn - Sunday, March 24, 2013 - link

    Oh no it won't ! this is amd man! nothing hurts when it's amd ! amd yes it can ! Reply
  • Quizzical - Friday, March 22, 2013 - link

    Your chart shows Radeon HD 6870 FP64 performance as N/A. I think it's 1/20 of FP32 performance, but I'm not sure of that. It definitely can do FP64, as otherwise, it wouldn't be able to claim OpenGL 4 compliance. Reply
  • MrSpadge - Friday, March 22, 2013 - link

    No, it doesn't have any HARDWARE FP64 capabilities. It's always possible to emulate this at slow performance via software, though. Reply
  • Quizzical - Friday, March 22, 2013 - link

    It's basically the same as what the 7770, 7790, and 7850 do, but they're not listed as N/A. The relevant question isn't whether you can do it more slowly, but how much more slowly. Reply
  • MrSpadge - Tuesday, March 26, 2013 - link

    No, it's not the same, the GCN cards have hardware FP64 capabilities. Reply
  • Ryan Smith - Friday, March 22, 2013 - link

    Let's be clear here. 85W is not the TDP. The TDP is higher (likely on the order of 110W or so). However AMD chooses not to publish the TDP for these lower end cards, and instead the TBP. Reply
  • alwayssts - Friday, March 22, 2013 - link

    Yeah, I figure ~85 TBP/105w TDP because that would be smack between 7770/7850 as well as having 20% headroom (which also allows another product to have their TBP between there and 7850's max TDP with it's max tdp above it within 150w....ie ~120-125/150w). IIRC, 80w is the powertune max (TDP) of 7770, 130w for 7850. 85w is the stock operation (TBP) of 7790.

    I really, really dislike how convoluted this power game has become...can you tell?!

    First it was max power. Then it was nvidia stating typical power (so products were within pci-e spec) with AMD still quoting max, which made them look bad. Then we get this 'awesome' product segmentation with 7000 having TBP and max powertune TDPs to separate them, while nvidia quotes TBP and hides the fact the TDP limits for their products exist unless you deduce them from the percentage you can up the boost power.

    AAAAaaaarrrrrghhhhh. I miss when the product you had could do what you wanted it to, ie before software voltage control and multiple states, as for products like this it gives the user less control and the companies a ton to create segmentation. Low-end stock products may have been less-than-stellar back in the day, but with determination you could get something out of it without some marketing stating it should fit x niche so give it y max tdp so it doesn't interfere with the market of z product.
    Reply
  • CeriseCogburn - Friday, March 22, 2013 - link

    Maybe so you couldn't blow the crap out of it then return it for another one, then another one, as "you saved money" and caused everyone else to pay 25% more since you overclock freaks would blow them up, then LIE and get the freebie replacement, over and over again.

    Maybe they got sick of dealing with scam artist liars... maybe they aren't evil but the end user IS.
    Reply
  • Spunjji - Friday, March 22, 2013 - link

    Why would the design power be higher than the total board power? :/ You're correct that the figure they're quoting isn't TDP but then you just went and made up a number.

    Here's some actual power consumption measurements of a 7770:
    http://www.techpowerup.com/reviews/HIS/HD_7770_iCo...

    So using Ananad's figures to extrapolate you can expect this thing to be ~90W max, usually lower than that at peak, right about where AMD put it.
    Reply

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