Original Link: https://www.anandtech.com/show/5314/xfxs-radeon-hd-7970-black-edition-double-dissipation-the-first-semicustom-7970



Traditionally the launch of a next-generation high-end video card has been a staggered process. In the name of getting cards out as soon as possible the first cards are almost always reference cards coming preassembled straight from AMD or NVIDIA, which are then touched up in the livery of their partners before being boxed and sold. Only later on – particularly when there’s a solid supply of GPUs – can partners acquire individual parts and put together their custom designs.

But as it’s turning out the Radeon HD 7970 isn’t going to be a traditional launch. In a rare move AMD has loosened the leash on their partners just a bit, and as a result we’re seeing semi-custom cards planned for launch earlier than usual. XFX looks to be the first partner to take advantage of this more liberal policy, as alongside the reference cards being launched today they’re launching their first semi-custom 7970s.

AMD GPU Specification Comparison
  XFX Radeon HD 7970 Black Edition AMD Radeon HD 7970 AMD Radeon HD 6970 AMD Radeon HD 6870
Stream Processors 2048 2048 1536 1120
Texture Units 128 128 96 56
ROPs 32 32 32 32
Core Clock 1000MHz 925MHz 880MHz 900MHz
Memory Clock 1.425GHz (5.7GHz effective) GDDR5 1.375GHz (5.5GHz effective) GDDR5 1.375GHz (5.5GHz effective) GDDR5 1.05GHz (4.2GHz effective) GDDR5
Memory Bus Width 384-bit 384-bit 256-bit 256-bit
Frame Buffer 3GB 3GB 2GB 1GB
FP64 1/4 1/4 1/4 N/A
Architecture GCN GCN VLIW4 VLIW5
Transistor Count 4.31B 4.31B 2.64B 1.7B
Manufacturing Process TSMC 28nm TSMC 28nm TSMC 40nm TSMC 40nm
Price Point $599 $549 $350 $160

XFX has 4 7970s planned; half of which are using AMD’s reference cooler, and the other half using XFX’s twin fan Double Dissipation cooler. As is traditional with the first wave of customized cards, all of these cards are semi-custom as XFX is using AMD’s reference PCB. Fully custom cards will come farther down the line. Of these 4 cards, 2 of them will be launching today: XFX’s Core Edition pure reference card, and their customized Black Edition Double Dissipation model, which features both a factory overclock and XFX’s custom cooler. It’s the Black Edition Double Dissipation we’ll be looking at today.

XFX Radeon HD 7970 Lineup
  XFX Radeon HD 7970 Black Edition Double Dissipation XFX Radeon HD 7970 Black Edition XFX Radeon HD 7970 Double Dissipation XFX Radeon HD 7970 Core Edition
Product Number FX-797A-TDBC FX-797A-TNBC FX-797A-TDFC FX-797A-TNFC
Core Clock 1000MHz 1000MHz 925MHz 925MHz
Memory Clock 1.425GHz (5.7GHz effective) GDDR5 1.425GHz (5.7GHz effective) GDDR5 1.375GHz (5.5GHz effective) GDDR5 1.375GHz (5.5GHz effective) GDDR5
Cooler Double Dissipation Reference Double Dissipation Reference
Price Point $599 N/A N/A $559

The 7970 Black Edition Double Dissipation is XFX’s top 7970 card. XFX is binning the boards they receive from AMD to give their Black Edition lineup a moderately impressive launch day overclock. The 7970 BEDD ships at 1000MHz core (8% overclock) and 5.7GHz memory (4% overclock), on what’s proving to be a rather overclockable design for AMD. Notably they’re doing this without any extra voltage – both our reference and BEDD 7970s run at 1.17v – which means the BEDD’s power consumption is only marginally higher than the reference 7970.

Along with the factory overclock the BEDD features XFX’s Double Dissipation cooler. Like the 7970 reference cooler XFX is using a vapor chamber at the base of their heatsink to draw heat from the Tahiti GPU, which then leads to an aluminum heatsink that runs almost the entire length of the card. Airflow is provided by a pair of fans sitting on top of the heatsink, similar to a number of other double fan designs we’ve seen over the years. Meanwhile like the heatsink, the casing is also made out of aluminum, specifically brushed aluminum. Finally, XFX is using a custom bracket with their logo cut into it – they claim that this improves airflow, but compared to any other changes the difference would be minimal at best.

Compared to AMD’s reference blower design the biggest difference here is that like other twin fan designs the Double Dissipation cooler is fundamentally an open air internal exhaust design. This allows XFX to achieve a similar level of cooling as AMD’s design, but with less noise. The tradeoff of course is that with an internal exhaust case cooling becomes much more critical as the BEDD will be dissipating most of the 250W of heat a 7970 generates under load into the case rather than outside of it.

Because the card is based on an AMD PCB, the dimensions of the card are similar to the reference 7970. The PCB itself is 10.5” just like the reference card, but XFX’s cooler isn’t quite as long, shaving off roughly 0.3” compared to the reference card and making the entire package only 10.65” long. Meanwhile at the front of the card, since this is an AMD PCB the port layout is identical: 1 DL-DVI port, 1 HDMI port, and 2 miniDP ports, situated below XFX’s logo on their custom bracket.

Moving on to the packaging, XFX packages only a few additional items with the BEDD, and as a result the box not much bigger than the card. Inside you’ll find the usual driver CD and quick start guide, along with a metal XFX case badge, a mid-length CrossFire bridge, and a passive HDMI to SL-DVI adaptor. It’s interesting to note that XFX has not included the more expensive active miniDP to SL-DVI adaptor, contrary to AMD’s earlier claims that all 7970s would ship with one, so the BEDD is only good for driving 2 DVI monitors out of the box. Finally, XFX is offering a base 2 year warranty on the BEDD, which can be extended to a lifetime warranty (ed: not a double lifetime warranty) by registering the card within 30 days of purchasing it.

The MSRP on the BEDD is $599, $50 over the $549 MSRP for the reference cards. Even with the higher price it looks to either be popular or in short supply – we saw the card sell out at Newegg before our NDA even expired.

Winter 2011 GPU Pricing Comparison
AMD Price NVIDIA
  $750 GeForce GTX 590
Radeon HD 6990 $700  
XFX Black Edition Double Diss. $599  
Radeon HD 7970 $549  
  $500 GeForce GTX 580
Radeon HD 6970 $350 GeForce GTX 570
Radeon HD 6950 2GB $250  
  $240 GeForce GTX 560 Ti
Radeon HD 6870 $160  

 



The Test, Power, Temp, & Noise

CPU: Intel Core i7-3960X @ 4.3GHz
Motherboard: EVGA X79 SLI
Chipset Drivers: Intel 9.​2.​3.​1022
Power Supply: Antec True Power Quattro 1200
Hard Disk: Samsung 470 (240GB)
Memory: G.Skill Ripjaws DDR3-1867 4 x 4GB (8-10-9-26)
Video Cards: XFX Radeon HD 7970 Black Edition Double Diss.
AMD Radeon HD 7970
AMD Radeon HD 6990
AMD Radeon HD 6970
AMD Radeon HD 6950
AMD Radeon HD 5870
AMD Radeon HD 5850
AMD Radeon HD 4870
NVIDIA GeForce GTX 590
NVIDIA GeForce GTX 580
NVIDIA GeForce GTX 570
NVIDIA GeForce GTX 470
NVIDIA GeForce GTX 285
Video Drivers: NVIDIA ForceWare 290.36 Beta
AMD Catalyst Beta 8.921.2-111215a
OS: Windows 7 Ultimate 64-bit

We’ll start things in reverse today by first looking at the power, temperature, & noise characteristics of the 7970 BEDD. The custom cooler is the single biggest differentiating factor for the BEDD, followed by its factory overclock.

Radeon HD 7900 Series Voltages
Ref 7970 Load Ref 7970 Idle XFX 7970 Black Edition DD
1.17v 0.85v 1.17v

As we noted in our introduction, the BEDD ships at the same voltage as the reference 7970: 1.17v. Since XFX is using the AMD PCB too, the power characteristics are virtually identical, save for the overclock and the power draw of the two fans.

Even with two fans the idle power consumption of the BEDD is identical to the reference 7970. Meanwhile under load we see that the power consumption for the BEDD creeps up slightly compared to the reference 7970. With Metro 2033 we see system power consumption peak at 398W, 7W over the reference card, meanwhile under OCCT system power consumption peaks at 365W, 8W over the reference card.

It’s worth noting that as XFX has not touched the PowerTune limits for the BEDD, it’s capped at the same 250W limit as the reference 7970 by default. So far we haven’t seen any proof that the BEDD is being throttled at this level under any of our games or compute benchmarks, however we can’t completely rule this out as we still don’t have any tools that can read the real clockspeed of the 7970 when PowerTune throttling is active. Whenever an overclock is involved there’s always a risk of hitting that PowerTune limit before a card can fully stretch its legs, hence the need to be concerned about PowerTune if it hasn’t already been adjusted. As for our power tests, the difference seems to largely boil down to the higher power consumption of XFX’s fans when they’re operating above idle.

One of the key advantages of open air designs is that they do a better job of dissipating heat from the GPU, which is what we’re seeing here with the BEDD under idle. At 30C the BEDD is 4C cooler than the reference 7970, with all of that being a product of the Double Dissipation cooler.

However it’s interesting to note that temperatures under load end up being identical to the reference 7970. The BEDD is no cooler than the reference 7970 even with its radically different cooling apparatus. This is ultimately a result of the fact that the BEDD is a semi-custom card; not only is XFX using AMD’s PCB, but they’re using AMD’s aggressive fan profile. At any given temperature the BEDD’s fans ramp up to the same speed (as a percentage) as AMD’s fans, meaning that the BEDD’s fans won’t ramp up until the card hits the same temperatures that trigger a ramp-up on the reference design. As a result the BEDD is no cooler than the reference 7970, though with AMD’s aggressive cooling policy the reference 7970 would be tough to beat.

Finally taking a look at noise we can see the full impact of XFX’s replacement cooler. For XFX this is both good and bad. On the bad side, their Double Dissipation cooler can’t match the 7970 reference cooler when idling; 43.5dB isn’t particularly awful but it’s noticeable, particularly when compared to the reference 7970. Consequently the BEDD is definitely not a good candidate for a PC that needs to be near-silent at idle.

On the flip side under load we finally see XFX’s cooler choice pay off. AMD’s aggressive fan profile made the reference 7970 one of the loudest single-GPU cards in our lineup, but XFX’s Double Dissipation cooler fares significantly better here. At 48.1dB under Metro it’s not only quieter than the reference 7970 by a rather large 7dB, but it’s also quieter than every other modern high-end card in our lineup, effectively tying with the reference 6950. Even under our pathological OCCT test it only reaches 52dB, 5dB quieter than the reference 7970.

Ultimately where the BEDD was a poor candidate for noise under idle, it’s an excellent candidate for a quiet computer under load thanks to the open air nature of XFX’s Double Dissipation cooler, and certainly the launch card to get if you want a load-quiet 7970. Just don’t throw it directly up against another card in CrossFire, as these open air cards typically fare poorly without an open slot to work with.



Game Performance: Crysis, Metro, DiRT, Shogun, & Batman

As the 7970 BEDD is a factory overclocked card it has a leg up in performance on the reference 7970, with the specific advantage depending on the game and whether it benefits more from the 8% core overclock or the 4% RAM overclock. Since this is architecturally identical to the reference 7970 we won’t make any drawn out conclusions, but it’s easy enough to see the benefits of higher clockspeeds on a 7970 card.

The BEDD leads the reference 7970 by about 4% in Crysis, more closely trending the memory clockspeed difference than the core clockspeed difference.

With Metro the story is similar; at 2560 we’re seeing a 4% gain. At 1920 however that gain is closer to 8%, which may mean Metro is teetering on being memory bandwidth limited at the highest resolutions.

DiRT 3’s performance gains almost strictly mirror the increase in the core clock, if not lead it by a bit. For this reason DiRT 3 is clearly the most GPU limited title in our lineup, and the title to benefit the most from XFX’s factory overclock.

Shogun is much like Metro: around 4% at 2560, and around 8% at 1920, indicating that it too may be reaching the limits of the 7970’s memory bandwidth.

Batman meanwhile is far more consistent. The gains from XFX’s overclock are just under 4%, almost exactly matching the memory bandwidth difference.



Game Performance: Portal 2, Battlefield 3, Starcraft II, Civilization V

Regardless of the resolution and anti-aliasing setting used, the BEDD’s lead on the reference 7970 is always 7-8%, indicating that it’s another game largely GPU limited and one of the biggest benefactors of XFX’s factory overclock.

Battlefield 3 is also another consistent title. XFX’s 8% core clock and 4% memory clock overclock gets you 6-7% more on BF3, which is good news for XFX as this is one of the hardest games for the 7970 to pull away from the GTX 580.

With Starcraft II we’re back to seeing gains varying with the resolution. At 2560 it’s nearly 8% faster than the reference 7970, but at 1920 it’s only 5% faster. Based on what we’ve seen with AMD’s performance at 1680, AMD seems to have some general frame setup issues with SC2 that are limiting their ability to scale too far past 100fps, hence the weaker scaling at 1920.

Finally with CivV we have the biggest gap of them all. At 2560 the BEDD gains 8%, but at 1680 it’s only 1%. Whatever AMD has done with the 7970 to improve their performance in CivV this much, it apparently is resolution dependent. At lower resolutions the 7970 becomes more reliant on the CPU, probably a consequence of AMD’s lack of driver command list support.



Compute Performance

Compute tasks, in spite of the name, are not always purely GPU bound. Depending on the task memory bandwidth can also play a significant part – which is why memory bandwidth was the single biggest increase on the 7970 over the 6970 – and our compute benchmark end up reflecting this.

Among our tests only the DX11 Compute Shader Fluid sample fully benefits from the increased clockspeed of XFX’s factory overclock, gaining 9% over the reference 7970. Our Civilization V and SmallLuxGPU benchmarks meanwhile only gain 4-5%, and our AES benchmark only gains 2%, the latter likely due to the fact that the setup time for the program’s dataset does not decrease, only the execution time does.



Overclocking

Though XFX does not provide any overclocking tools for the BEDD, the card itself is advertised as an overclocking card to an extent. The use of the AMD PCB and a similarly high performing cooler means that overclocking results shouldn’t be much better or much worse than reference cards, but given how much potential we’re seeing out of the 7970 this is not a bad thing.

Even with XFX’s factory overclock the BEDD features the same 1125MHz overdrive limit as all current 7970 cards, so you have 125MHz (~11%) to play with within Overdrive. Based on our experience this is right at the edge of what’s this card is capable of – after pushing the card to 1150MHz through MSI’s Afterburner software we found that our sample peaked at 1125MHz anyhow, as anything beyond that impacted stability and caused artifacts. Meanwhile we were able to push our memory to 6.3GHz, as beyond that point performance plateaued as the need for error correction nullified our gains.

Our final clocks were 1125MHz core and 6.3GHz memory, representing a 21% core and 14% memory overclock over the reference 7970, or an 11% core and 11% memory overclock over XFX’s factory overclock. As the BEDD uses an AMD PCB it should be possible to use compatible voltage tweaking software to push it further, but for the time being we’re limiting ourselves to what the 7970 can do on stock voltage as the AMD PCB isn’t particularly overbuilt for overvolting. On that note we did increase our PowerTune limit to +20% (300W) in order to ensure PowerTune didn’t throttle our overclocked BEDD, though there appears to be headroom to spare in at least some of our games.

Radeon HD 7970 Overclocking
  Radeon HD 7970 Stock XFX Radeon HD 7970 BEDD XFX Radeon HD 7970 BEDD Overclock
Core Clock 925MHz 1000MHz 1125MHz
Memory Clock 1.375GHz (5.5GHz effective) GDDR5 1.425GHz (5.7GHz effective) GDDR5 1.575GHz (6.3GHz effective) GDDR5
Voltage 1.17v 1.17v 1.17v
PowerTune 250W 250W 300W

The end result of a further 11% overclock to both the GPU and memory clock results in a very consistent 11% performance increase across the board. From Crysis to Battlefield 3 everything jumps up by 11%, and the combination of the two overclocks means that our overclocked BEDD leaves just about every other single-GPU video card in the dust. Even the dual-GPU 6990 and GTX 590 have their leads seriously eroded, and in a few cases the overclocked BEDD will pull ahead of the GTX 590 in games that AMD does particularly well in. If the reference 7970 and BEDD didn’t impress you, certainly this will.

So what’s the tradeoff for this overclock? It’s actually very little. Even with our increased PowerTune limit – which doesn’t increase the power consumption, just the potential for power consumption – power consumption under Metro only rises 26W, and at least some of this will be additional work on the CPU in response to the relaxed GPU bottleneck. OCCT looks worse, but again this has more to do with the PowerTune limit than the overclock.

The fact that this overclock has had a minimal impact on the power consumption of our BEDD is reinforced by our temperature and noise data. Under Metro the overclocked BEDD gets 1C warmer and 2dB louder versus its factory clocks, which is a very small increase given the 11% overclock. So long as we don’t touch the core voltage for the BEDD (or any other 7970), the power tradeoff for overclocking is nearly non-existent, which is fantastic news given that we’ve just driven a 7970 21% over AMD’s reference clocks on reference voltage.



Final Words

Being the first mover in any market has its advantages, and this is especially true for XFX’s Radeon HD 7970 Black Edition Double Dissipation. While there’s nothing here we haven’t seen in the past on other video cards – a custom cooler and a moderate factory overclock – for the time being XFX is the only vendor offering either of those. Not surprisingly the Black Edition Double Dissipation appears to have sold out over at Newegg before our NDA even expired.

At this point in time XFX’s biggest advantage is that they’re the only vendor offering an open air cooler. There are obvious tradeoffs in these designs and it’s definitely not suited for everyone, but for cases that can handle the heat load of an open air cooler, XFX’s Double Dissipation cooler makes the resulting card significantly quieter than the reference design under load, offering the performance of a 7970 with less noise than any current high-end card. The only thorn in XFX’s side here is that their idle noise is a bit high, something I suspect they’ll fix on their first fully custom card when they can program in a more fitting fan profile.

Meanwhile XFX’s factory overclock gives the Black Edition Double Dissipation a distinct edge over the reference 7970 and any cards at similar clockspeeds, but I don’t believe this is as a significant advantage for the Black Edition Double Dissipation as its cooler. There’s plenty of evidence that most if not all 7970s can reach XFX’s factory overclock, so you’re effectively paying for the privilege of having those speeds pre-burnt into the BIOS. Not that there isn’t a place for a factory overclock, but unless you’re absolutely sheepish about doing it yourself, there’s probably nothing here you can’t do on your own. At best an argument can be made that by grabbing a pre-binned card you can expect a better aftermarket overclock – and you’ll absolutely want to do some overclocking of your own as we were able to get another 125MHz out of our sample.

Of course XFX isn’t giving this away for free – the Black Edition Double Dissipation comes at a $50 premium making it a $599 card, and the notable absence of the active miniDP to SL-DVI adaptor means you’d need to shell out another $25 to build a kit at parity to most other vendors' 7970 kits. Nevertheless XFX has generally earned their price premium. If you were satisfied with the reference 7970’s performance for its price, then the Black Edition Double Dissipation is not far off that curve, though at the end of the day it’s a factory overclocked card and you are definitely paying a premium for that.

With that said, if you’re looking to save a buck we’d suggest keeping your eyes open for the non-Black Edition version of the Double Dissipation card in the future. Without the factory overclock it should be a bit cheaper than the Black Edition, conferring the same advantages of the open air cooler without quite the price premium.

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