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The Radeon HD 5670 Architecture

ATI Radeon HD 5670: DirectX 11 For $99
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Thus far, AMD's Radeon HD 5000-series has demonstrated a predictable relationship between the high-performance models ending in the suffix '70,' each successively-lower model offering half of the stream processors of its more powerful cousin. The Radeon HD 5670 continues this trend:


Radeon HD 5970
Radeon HD 5870
Radeon HD 5770
Radeon HD 5670
Shader Processors:
3,200
1,600
800
400
Texture Units:
160
80
40
20
Color ROPs:
64
32
16
8
Core Clock:
725 MHz
850 MHz
850 MHz
775 MHz
GDDR5 Memory Clock:
1000 MHz
1200 MHz
1200 MHz
1000 MHz
Memory Bus:
256-bit
256-bit
128-bit
128-bit
Data Rate:
8 Gb/s
9.6 Gb/s
4.8 Gb/s
4 Gb/s
Compute Power (TFLOPs):
4.64
2.72
1.36
0.62
Transistors (Billions):
4.3
2.15
1.04
0.627
Maximum Power:
294W
188W
108W
61W
Idle Power:
42W
27W
18W
14W


What's interesting here is that the new Radeon HD 5670 offers similar memory bandwidth compared to the higher-end Radeon HD 5770. Both cards offer a 128-bit bus with GDDR5 memory on-board, resulting in memory performance that isn't all that different.

Let's look at the Radeon HD 5670 block diagram for a better idea of how it compares to its siblings:

We went through the Radeon HD 5000-series architecture in detail in our Radeon HD 5870 launch article, so I won't rehash the minutia. We will look at the differences in the Radeon HD 5670 though. In short, the 5670 is one quarter of a 5870. It contains five SIMD engines, each with four texture units and 16 stream processors, and each stream processor with its five ALUs (which ATI calls Stream Cores). As a result, this GPU boasts 400 stream cores and 20 texture units. Note that there are two 64-bit memory controllers sharing two render back-ends. Each render back-end contains four color ROP units resulting in a total of eight ROPs and a 128-bit memory interface.

Lets compare this to the Radeon HD 4770 we're hoping the new Radeon HD 5670 will be able to compete with:


Radeon HD 5670Radeon HD 4770
Shader Processors:
400
640
Texture Units:
20
32
Color ROPs:
8
16
Core Clock:
775 MHz
750 MHz
GDDR5 Memory Clock:
1,000 MHz
800 MHz
Memory Bus:
128-bit
128-bit
Data Rate:
4 Gb/s
3.2 Gb/s
Transistors (Billions):
.627
0.826


Our hopes that the Radeon HD 5670 will meet Radeon HD 4770 performance are somewhat dashed to some extent. The Radeon HD 4770 has more than a 50% increase in ALUs and texture units compared to the new 5670, not to mention two times the ROPs. The only real advantage the 5670 can boast compared to its previous-generation predecessor is a bit more bandwidth, due to a higher memory speed. Based on this, we're going to predict that the Radeon HD 5670 will fall well short of the 4770 when it comes to 3D gaming, and will instead have to pick up the slack with its value-added features.

The Radeon HD 4850 and 4770 are on the verge of extinction, which will open up some breathing room for the new $100 card in ATI's own lineup. The demise of the respectable GeForce 9800 GT and GTS 250 is less certain with GF100 (Nvidia's next-gen graphics architecture) delayed.

Of course there are quite a few capabilities that the Radeon HD 5000-series cards are able to boast currently not offered by its competition. For example, this card doesn't require a dedicated power connector. Moreover, you get some of the extras covered in previous Radeon HD 5000-series introductions: DirectX 11, Eyefinity, and bitstreaming Dolby TrueHD and DTS-HD Master Audio formats. Let's talk about how these features work on the Radeon HD 5670.

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Top Comments
  • 17 Hide
    stridervm , January 14, 2010 5:28 AM
    I wish there was a Radeon 4850 in the comparison chart for.... Comparison....
  • 12 Hide
    duckmanx88 , January 14, 2010 5:46 AM
    notty22Just meh, no reason for this card to exist at all.


    low price point, low power consumption, and extremely close to the 9800GT in performance. Plenty of reasons to like this card. especially for a casual Sims or Torchlight gamer.
  • 10 Hide
    cleeve , January 14, 2010 2:15 PM
    LavaconThat said, this was a good review, but, we could use a little less bias around here. Had this review been about yet another renamed Nvidia card, THG would have been singing it's praise.


    No.

    I've explained this before. I've explained it in the forums back then, I even explain it in the last page of this review, and I'll explain it again to make it clear:

    When the GT 240 was introduced we were told it would be sub-$100 and weren't given much more than that for pricing detail. After seeing the performance, I assumed the price would drop to where it makes sense in the market - it seemed obvious that the cheaper-to-produce GT 240 would give Nvidia the flexibility to compete on price where the 9600 cards were expensive to produce. It honestly never occurred to me that they'd keep it priced against the vastly superior 4850. In fact, prices have dropped, and probably will continue to drop - but they're not even close to where they need to be for the GT 240 to make sense.

    In any case, that assumption was a mistake, or premature at the very least. I'm not perfect, never claimed to be. But that mistake is not bias. And I'm not willing to make that mistake again regardless of the manufacturer. So I am a bit more cautious about the conclusion this time.

    I acknowledge this on the last page of this review, actually I devoted a good paragraph to it. If this was biased, I'd be extolling the virtues of the GT 240 - I am not. It's a bad buy at the current price and I don't think I'm saying otherwise. This review makes it clear that the GT 240 is redundant at current pricing. If this review was biased against AMD, I wouldn't be steering people to the 4850, would I?

    No bias here dude, just caution to not repeat the same mistake. The 5670 has the potential to be a great card for the $, and if it drops to $80 I'll be extolling it's virtues from the rooftops. Even if it comes down to $90 I'll give it more props. That's common sense, not bias. Would it have made you feel better if I had recommended it over the 4850 at the same price?





Other Comments
  • 4 Hide
    amdfangirl , January 14, 2010 5:08 AM
    4800x900? Are you serious?

    Otherwise, great review. Just curious, are you going to make Flash 10.1 playback a benchmark? I'm just interested.
  • 3 Hide
    amdfangirl , January 14, 2010 5:13 AM
    Oh yes, could you add the hierarchy chart and show where the HD 5670 fits in?
  • 17 Hide
    stridervm , January 14, 2010 5:28 AM
    I wish there was a Radeon 4850 in the comparison chart for.... Comparison....
  • -7 Hide
    noob2222 , January 14, 2010 5:36 AM
    If it weren't for the 4770, this would be priced decently, at the same price it kills the 240. If they were to lower the price to $80 for the 5670, the 240 would get the dumb buy of the year award. IMO $90 would be about right, $80 is definatly too cheap.

    Quote:
    Here it will have to compete against the similarly-performing $80 GeForce 9600 GT


    ... wrong. it won crysis, was close in far cry2 and Hawx. It was slaughtered in the rest of the games by the 5670.

  • -5 Hide
    notty22 , January 14, 2010 5:40 AM

    ..................Radeon HD 5670 Radeon HD 4770
    Shader Processors 400 640
    Texture Units: 20 32

    Color ROPs: 8 16

    Those numbers against the 4770 show, a crippled card. Is this to leave something in the cupboard for the next generation ?
    Just meh, no reason for this card to exist at all.

  • 2 Hide
    belial2k , January 14, 2010 5:43 AM
    I think the points made here about the pricing could be made about the entire 5xxx series. At no point in the entire line is there a GOOD value. Everything can be beaten in price/ performance by previous generation cards or combination of cards...even the 5870 loses badly to two 4890s for less money. The only thing they have going for them is DX11 and eyefinity, which for most gamers are rather questionable "value" adds because of the huge hit DX11 gives framerates and the 3 monitors needed for eyefinity. All these cards need to come down in price before they become smart price/performance buys.
  • 12 Hide
    duckmanx88 , January 14, 2010 5:46 AM
    notty22Just meh, no reason for this card to exist at all.


    low price point, low power consumption, and extremely close to the 9800GT in performance. Plenty of reasons to like this card. especially for a casual Sims or Torchlight gamer.
  • 2 Hide
    cleeve , January 14, 2010 5:47 AM
    noob2222It was slaughtered in the rest of the games by the 5670.


    "Slaughtered". +1 for hyperbole!
  • -7 Hide
    noob2222 , January 14, 2010 6:08 AM
    Cleeve"Slaughtered". +1 for hyperbole!

    What would you call 12-20% faster across the board?
    oh, right, "similar" noting like the pot calling the kettle black huh.
  • -4 Hide
    Otus , January 14, 2010 6:10 AM
    4850 and 4770 will be out soon and prices for what units are left will probably rise in price. There's probably room for price cuts for 5670 at a
  • 3 Hide
    cleeve , January 14, 2010 6:11 AM
    noob2222What would you call 12-20% faster across the board?


    I'd call it "similar". Because the user experience is "similar".

    An actual human being would probably not be able to experience most of the differences that you're suggesting are monumental.
  • 0 Hide
    cleeve , January 14, 2010 6:17 AM
    Quote:
    Oh yes, could you add the hierarchy chart and show where the HD 5670 fits in?


    I'll be adding it to the existing hierarchy chart soon! :) 
  • 0 Hide
    cleeve , January 14, 2010 6:18 AM
    Quote:
    I wish there was a Radeon 4850 in the comparison chart for.... Comparison....


    Didn't have time to include both the 4850 and GTS 250, but they'll perform close to the 5750 and certainly better than the 4770.
  • 0 Hide
    noob2222 , January 14, 2010 6:21 AM
    CleeveI'd call it "similar". Because the user experience is "similar".An actual human being would probably not be able to experience most of the differences that you're suggesting are monumental.

    then why bother saying the 9800 is slightly faster, it would be just as similar in comparison.
  • 1 Hide
    amdfangirl , January 14, 2010 6:29 AM
    Quote:
    I'll be adding it to the existing hierarchy chart soon! :) 


    I reckon adding the chart to the end of GPU reviews would greatly help.

  • 0 Hide
    WINTERLORD , January 14, 2010 7:29 AM
    would love to see the 4670 in crossfire. any idea what it will beat
  • -1 Hide
    anamaniac , January 14, 2010 7:30 AM
    Yay, a 40nm 4670 with GDDR5...
    Is that really all it is?
    I just picked up some guys used 5770 for $150 (I'm Canadian, they cost $200 locally).
    Other than not needing any external power cables, useless.

    Go pick up a used 5750 from Craigslist instead people...
  • 6 Hide
    cleeve , January 14, 2010 7:37 AM
    Quote:
    then why bother saying the 9800 is slightly faster, it would be just as similar in comparison.


    Wow. Bickering over the minutia is what you're all about, isn't it? :D 
  • 2 Hide
    mitch074 , January 14, 2010 7:56 AM
    And here, I'm happy I decided 18 months ago that the 4850 was a good deal, if it's still powerful enough to be considered 'upper mainstream' in a world where cards twice as powerful as what came before come out every 9-12 months.

    My only regret is that those early models were soon forgotten by their makers, and they need heavy tweaking to get the juice out of them.

    The huge cooler I put on it made it much cooler (the original cooler failed), and virtually silent. The VBIOS hack I applied, reducing frequencies to 160/500 MHz, 0.92V at idle may have helped in the power draw department (it sure helped before the cooler change, by lowering temps from 80°C to 65°C), but probably not as much as these more recent cards.

    I'd love a similarly tweaked 4850 (more recent models actually offer most of these out of the box: dual slot cooler and tweaked freqs/voltages) being fully benched against these.
  • 3 Hide
    Anonymous , January 14, 2010 8:57 AM
    Pretty good review, actually Cleeve this is the best review I've seen you do yet.

    And yes, at $99 this card is too expensive. At $79 it would kill Nvidia off, maybe ATI don't want that.

    If you can, would be great to see 2 of these in crossfire soon.
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