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In 2009-2010, AMD launched the entire 4 chip Evergreen series in 6 months. By previous standards this was a quick pace for a new design, especially since AMD had not previously attempted a 4 chip launch in such a manner. Now in 2012 AMD’s Southern Islands team is hard at work at wrapping up their own launch with new aspirations on quickness. Evergreen may have launched 4 chips in 6 months, but this month AMD will be completing the 3 chip Southern Islands launch in half the time – 3 chips in a mere 3 months.

To that end today AMD is taking the wraps off the final piece of the Southern Islands puzzle: Pitcairn. The middle child of the family, it will be the basis of AMD’s $250+ enthusiast segment Radeon HD 7800 series. We’ve seen AMD capture the high-end with the 7900 series and struggle to control the mainstream market with the 7700 series, but how does the 7800 series fare amidst AMD’s lead in deploying 28nm GPUs? Let’s find out.

AMD GPU Specification Comparison
  AMD Radeon HD 7870 AMD Radeon HD 7850 AMD Radeon HD 6970 AMD Radeon HD 6950 AMD Radeon HD 5870
Stream Processors 1280 1024 1536 1408 1600
Texture Units 80 64 96 88 80
ROPs 32 32 32 32 32
Core Clock 1000MHz 860MHz 880MHz 800MHz 850MHz
Memory Clock 4.8GHz GDDR5 4.8GHz GDDR5 5.5GHz GDDR5 5.0GHz GDDR5 4.8GHz GDDR5
Memory Bus Width 256-bit 256-bit 256-bit 256-bit 256-bit
Frame Buffer 2GB 2GB 2GB 2GB 1GB
FP64 1/16 1/16 1/4 1/4 1/5
Transistor Count 2.8B 2.8B 2.64B 2.64B 2.15B
PowerTune Limit 190W 150W 250W 200W N/A
Manufacturing Process TSMC 28nm TSMC 28nm TSMC 40nm TSMC 40nm TSMC 40nm
Architecture GCN GCN VLIW4 VLIW4 VLIW5
Price Point $350 $250 N/A N/A N/A

So what exactly is Pitcairn? In a nutshell, take Cape Verde (7700) and double it, and you have Pitcairn. Pitcairn has twice the number of CUs, twice the number of ROPs, twice the memory bandwidth, and of particular importance twice as many geometry engines on the frontend. This works out to 1280 SPs among 20 CUs – organized as a doubling Cape Verde’s interesting 4/3/3 configuration – 80 texture units, 32 ROPs, 512KB L2 cache, and a 256-bit memory bus. Compared to Tahiti, Pitcairn still has 12 fewer CUs and as a result less shader and texturing performance along with the narrower memory bus, but it has the same number of ROPs and the same frontend as its bigger brother, which as we’ll see creates some very interesting situations.

On the functionality side of things, the Cape Verde comparisons continue. As with all Southern Islands family parts, Pitcairn supports things such as DX10+ SSAA, PowerTune, Fast HDMI support, partially resident textures, D3D 11.1 support, and the still-AWOL Video Codec Engine (VCE). FP64 support is once again present, and like Cape Verde it’s a performance-limited implementation for compatibility and software development purposes, with FP64 performance limited to 1/16th FP32 performance.

AMD’s Pitcairn cards will be the Radeon HD 7870 GHz Edition and the Radeon HD 7850. The 7870 is a full Pitcairn, clocked at 1000MHz core and paired with 2GB of GDDR5 running at 4.8GHz. It has a PowerTune limit of 190W while AMD puts its typical board power draw closer to 175, meanwhile idle power consumption is around 10W with a long idle of 3W like the rest of Southern Islands. As for the 7850 it’s the typical lower tier part, featuring 16 active CUs (1024 SPs), an 860MHz core clock, and the same 2GB of GDDR5 running at 4.8GHz as its counterpart, giving it roughly 68% the shading/texturing performance and 86% of the ROP & frontend performance of the 7870. The PowerTune limit is 150W with a typical board power of 130W, and the same 10W/3W idle power consumption as the 7870.

Altogether the 7800 series isn’t just the successor to the Barts based 6800 series in name but also the successor to the 6800 in design. This includes not only power consumption, with one card being a sub-150W part, but also with regards to things such as CrossFire, where it features a single CF connector. Interestingly enough even though Barts was already a fairly small chip for its performance, Pitcairn takes this one step further with a die size of 212mm2, which in turn contains 2.8B transistors, only 160M more than Cayman. As we’ll see when we get to our benchmarks, this makes Pitcairn a surprisingly small chip given its 6970+ performance.

Speaking of the 6970, let’s talk about the 7800 series’ competition. As AMD began winding down Cayman (6900 series) almost immediately with the launch of the 7900 series, at this point the 6900 market has effectively dried up. Having taken themselves out of competition with themselves, AMD’s only competition is NVIDIA’s lineup. From a performance and price basis the 7870 and 7850 don’t map particularly well to any specific NVIDIA products, but generally speaking they’re targeted against the GTX 570 and GTX 560 Ti respectively.

With AMD targeting the ~$320 570 and ~$210 560 Ti and given their conservative pricing on the rest of Southern Islands, it should come as no surprise that the 7800 series is priced equally conservatively. The 7870 will have an MSRP of $350, while the 7850 will have an MSRP of $250. With the 7800 series completing the launch of Southern Islands, this gives AMD a consistent price structure for the entire family: $550, $450, $350, $250, $159, and $109.

Finally, as far as availability goes this will be a delayed launch. AMD is formally unveiling the 7800 series today, but it will not go on sale until the 19th, 2 weeks from now. AMD has said that this is due to both CeBIT and the Game Developers Conference; AMD and their partners want to be able to show off the 7800 series to their respective attendees at those events, with both events being far too large to keep the 7800 under wraps. This delayed launch also means that partner cards aren’t quite ready yet, so we only have AMD’s reference cards on hand. We’ll be taking a look at partner cards later this month.

Spring 2012 GPU Pricing Comparison
AMD Price NVIDIA
Radeon HD 7950 $450 GeForce GTX 580
Radeon HD 7870 $350  
  $330 GeForce GTX 570
Radeon HD 7850 $250  
  $200 GeForce GTX 560 Ti
  $179 GeForce GTX 560
Radeon HD 7770 $159  

 

Meet The Radeon HD 7870 & Radeon HD 7850
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173 Comments

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  • DeViLzzz - Monday, March 05, 2012 - link

    It is not the dumbest statement ever. Have you looked at multiple sites benchmarks ? Clearly a 2 GB 6950 Power Color flashed to a 6970 or a 6970 is worth keeping. Hardly an improvement over those situations for the price you would be paying for a 7870 and 7850. Reply
  • ExarKun333 - Monday, March 05, 2012 - link

    Then you don't follow the graphic card industry very well at all. Reply
  • MadAd - Monday, March 05, 2012 - link

    did i just read a different review? looking at this i did - Im on the 6950 and no theres not enough performance difference.

    also, comparing apples to oranges and saying theres a gain isnt going to work - if someones going to OC a 7*** then im sure they have also OC their 6***, so comparing a straight 6*** to the 7*** OC results and calling it a difference is smoke and mirrors.
    Reply
  • cactusdog - Monday, March 05, 2012 - link

    You guys dont get it. Why are you comparing the 7870 to a 6950? Should be the 6870 but even then The 7870 smashes the 6950 when overclocked. the 7870 performs like a stock 7970 when overclocked. You cant compare overclocking on the 6 series to the 7 series. The 7 series is the sandy bridge of GPUs.

    Why compare last gens high end to this gens mid range? If you have a 6950/6970 you should be looking at a 7950/7970. A 7950/7970 will give you 70% increase in performance when overclocked. AMD left heaps of overclocking headroom for easy overclocking.

    Sure, the price is a little high now, but just wait a few weeks until Nvidia cards arrive and prices will come down. New tech is always a little expensive when it first comes out but no one is forcing you to buy now. Just wait a couple of weeks
    Reply
  • Kiste - Tuesday, March 06, 2012 - link

    "Why compare last gens high end to this gens mid range?"

    Because were introduced at the same price point. Video card names/numbers are completely arbitrary, you have to compare cards at a given price point.
    Reply
  • xrror - Monday, March 05, 2012 - link

    So I have one the the early 6950 2GB cards unlocked to 1536 shaders, and a 935/1275 overclock.

    Running at 1920x1200 in skyrim with the high resolution texture packs from Bethesda starts to lag.

    Yes I'm being petty, but as a PC gaming smoe, I'm looking for a card that's under $300 that will dominate what I have.

    I can't find a confident vote for a strong successor in the sub $300 range to replace my current card.

    This makes me sad. Also with all the growing pains 69xx series had - and AMD's dumping of VLIW4 makes me pretty sure 69xx is a dead end for any future driver improvements.

    Maybe I can sell my 6950 for $100 to subsidize a 79xx or a Kepler?
    Reply
  • Zoomer - Wednesday, March 07, 2012 - link

    I'll take it. Reply
  • mpschan - Monday, March 05, 2012 - link

    I'd tend to agree with your assessment. Only those looking for bleeding edge performance should consider the upgrade to the 7900 series.

    The price/performance curve is a little disappointing, but not unexpected. This is what happens when you:

    a) Move to a new process
    b) Implement a new architecture
    c) (Most importantly) Have no competition

    They need to make their money back on the first two, and having no competition allows them to do that and then some.

    But look at the thermals and power draw. Decreased power usage with a small gain in performance? Where have I seen that before ... oh I know, Intel!

    Welcome to tick-tock folks. They took their process shrink and used it to allow them to draw less power, not tear up the performance charts.

    This means the next generation on 28nm has room to expand. 1280 SP for the 7870 can be 1600 for the 8870. A 212mm2 die can be 300mm2. 190w can be 220w.

    Ultimately the performance of these cards will come down to power drawn. The huge jumps in performance that we used to see existed because of drastically improving fabrication technologies combined with better ways of rendering screens. I think those days will be few and far between now.
    Reply
  • arjuna1 - Monday, March 05, 2012 - link

    You have a point, this generation is not worth spending the $$$ to "sidegrade". I don't kepler doing anything to change that other than forcing AMD to have decent prices. Reply
  • cactusdog - Monday, March 05, 2012 - link

    How is a 7950/7970 a "sidegrade"?? To a 6950/6970? Its a massive performance increase. If you have a highend 6 series GPU you should be looking at highend 7 series. Not midrange. Reply

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