Meet The Radeon 4770

With 826 Million transistors, the RV740 GPU that powers the Radeon HD 4770 features a native 640 SP (128 five-wide vector units arranged in 8 SIMD cores) as opposed to the 640 cut-down-from-800 SP 4830. Among the other differences is the fact that the 4770 hooks into GDDR5 over a 128-bit memory bus at almost the same clock speed (producing just a little bit less bandwidth at half the pinout).

AMD reports average TDP to be about 80W, so despite the fact that this is a 40nm part that pulls a little less power for the same job than its older brothers, the Radeon HD 4770 still requires a 6-pin PCIe power connector. This isn't a huge amount of power, and AMD has single slot boards that fall in to this range. Of course, it likely gets a little more complicated at 40nm when you have less surface area to dedicate to heat transfer. Thus this is a dual slot part rather than a single slot part. Such is life.

So, rather than a totally killer single slot card with no power connector at $99, we've got a dual slot card with a power connector at $110. Not ideal, but we can work with that. Rather than the 40nm process, form factor or targeted design being the selling point, the real issue is going to be the competition.

We will be comparing the Radeon HD 4770 to the GeForce GTS 250 512MB (aka the 9800 GTX+) and the GeForce 9800 GT. These two cards sort of sandwich the Radeon HD 4770 in terms of price with the 9800 GT coming in at $100 and the GTS 250 512MB at slightly more than $120. So the question will continually be: does the extra +/- $10 make a difference.

This part essentially improves upon and usurps the position of the Radeon HD 4830. Word from AMD was that we should see the 4830 start to fall by the wayside. For our analysis we are including the Radeon HD 4830 and the Radeon HD 4850. Here's a breakdown of how the AMD hardware stacks up:

ATI Radeon HD 4770 ATI Radeon HD 4850 ATI Radeon HD 4830
Stream Processors 640 800 640
Texture Units 32 40 32
ROPs 16 16 16
Core Clock 750MHz 625MHz 575MHz+
Memory Clock 800MHz (3200MHz data rate) GDDR5 993MHz (1986MHz data rate) GDDR3 900MHz (1800MHz data rate) GDDR3
Memory Bus Width 128-bit 256-bit 256-bit
Frame Buffer 512MB 512MB 512MB
Transistor Count 826M 956M 956M
Manufacturing Process TSMC 40nm TSMC 55nm TSMC 55nm
Price Point $110 $130 $100

It's worth noting that the bandwidths of the 4770 and the 4830 are 51.2GB/s and 57.6GB/s respectively.

We have also tweaked a couple of our tests to better target the ~$100 segment. The biggest change was with our Crysis test where we dropped everything down by one quality level ending up with all mainstream settings except for gamer shaders. The other was just a small tweak: not pushing things beyond the high quality default settings in Age of Conan (though we did enable 4xAA).

In the middle of testing, we accidentally let our copy of Left 4 Dead update itself rendering our benchmark un-timedemo-able. Thus we have to leave Left 4 Dead performance out of this article, but we can say that at the highest quality settings the 4770 is capable of playable framerates at up to 1680x1050.

Our test setup is still the Intel platform with a top of the line CPU in order to remove any other bottlenecks from the system. These performance numbers show the potential the graphics card has to offer. If the rest of a system is unable to achieve performance levels along the lines of what we show here, then it doesn't matter what graphics card we plug in at this price: it will end up performing pretty much the same as any other option (at the system bottleneck level). These tests show the potential of a graphics card when the potential of the graphics card makes a difference. That said, most Phenom II, Core 2, and Core i7 systems will be very close to these numbers at the common resolution of 1680x1050 with the tested hardware; the fast system/CPU generally only becomes a factor at lower resolutions or with multiple GPUs.

Test Setup
CPU Intel Core i7-965 3.2GHz
Motherboard ASUS Rampage II Extreme X58
Video Cards ATI Radeon HD 4770
ATI Radeon HD 4830
ATI Radeon HD 4850
NVIDIA GeForce GTS 250
NVIDIA GeForce 9800 GT
Video Drivers 9.4, 9.4 Beta for 4770
ForceWare 185.68
Hard Drive Intel X25-M 80GB SSD
RAM 6 x 1GB DDR3-1066 7-7-7-20
Operating System Windows Vista Ultimate 64-bit SP1
PSU PC Power & Cooling Turbo Cool 1200W

Without further ado, here's the performance numbers.

Index Age of Conan Performance
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  • balancedthinking - Tuesday, April 28, 2009 - link,682645/Test-Ati-...">,68264...force-98...
  • Zstream - Tuesday, April 28, 2009 - link

    It is because Derek wrote the article. As long as he is benchmarking and testing the AMD bashing will continue. Just get used to it.
  • Jamahl - Tuesday, April 28, 2009 - link

    The important thing here is there is no attempt by ATI to deceive the public.

    All the 48xx cards have 256-bit buses, and they also have higher bandwith than the 4770. However, the 4770 has much more in common with a 4870 than it does a 4830 or 4850, namely clock speeds and DDR5. It just so happens that its peformance level drops in at the 4850 mark due to the smaller 128 bit bus and a few less shaders.

    If you look at it logically, it's a cut down 4870. 4770 is the best name that could have been chosen for it taking everything into consideration.
  • coldpower27 - Wednesday, April 29, 2009 - link

    I think it kinda makes sense.

    The first digit explains the generation of technology.

    4 = RV7xx Series with DX10.1 Technology. (Current)
    3 = RV6xx Series with DX10.0 Refresh Line
    2 = R600 Series with DX10 Original Line

    The second digit explains where the product Series slots in with regard to everything else...

    8 = Performance
    7 = Mainstream Refresh
    6 = Mainstream
    5-3 = Budget...(this should be consolidated)

    The Third digit is an isolated variable and explains where it slots within this particular series..

    7 = Top Card.
    5 = Middle Card.
    3 = Low Card.

    The Last digit current serves no purpose...

    it's a bit more simple I will admit then Nvidia's nomentclature.

    With ATI having 7,5,3 for defining top, middle and low of a particular range.

    I will try to insert an analgous numbering concept for Nvidia.

    Nvidia has GTX+ = 8 GTX = 7 GTS = 6, GT = 5, GS = 3, GSO = 2

    I think... very complicated conmpared to 3 SKU's for ATi. At least Nvidia is trying to make some headway into making a unified product line with the GTS 250, GTX 260, GTX 275, GTX 285...

    GTX 260 Core 216, should have been GTX 265 for simplicity sake...
  • flipmode - Tuesday, April 28, 2009 - link

    I agree with the author in his criticism of the name chosen for the product.

    4845 if you want to end odd
    4840 if you do not care

    Naming these products should not be this hard. What AMD and Nvidia need to be passionate about is helping the buyer make sense of it all.

    Also - like the author said - why the hell bother with the 4th digit if it is just going to be -0- all the time. Put that son of a bizzle to work.
  • flipmode - Tuesday, April 28, 2009 - link

    Um yeah, the author seems to think the dual slot cooler is an inconvenience, but I'd LOVE to have a dual slot cooler that pumps the hotness outside of the case for me. Most mobo makers are careful enough about the slot below the PCIe16 slot because, believe it or not, they've thought about the fact that a dual slot graphics card might be put in there.
  • JimmiG - Tuesday, April 28, 2009 - link

    Many who buy these lower-end cards have more compact systems, sometimes with m-ATX boards.

    When I got my 4850 last year I had such a board, meaning a dual slot card would have blocked one of the two PCI slots, and made the last one nearly useless since the PCI card would sit right against the videocard, possibly blocking the fan.

    Even though I've got a full ATX board now, the lack of hot air exhaust doesn't bother me. The two 80mm fan+PSU fan take care of getting the hot air out of the case. In fact they move much more hot air than the small GPU fan.

    There will probably be variations just like with all other cards so those who want single slot will be able to find one. Prices will also go below $100 in a matter of weeks, IMO.
  • Griswold - Wednesday, April 29, 2009 - link

    This isnt a lower-end card. Its a mid-range card. Low-end is often passive cooled. The single slot cooler on the 3850 and 4850 are misserable for this type of GPU. But i'm sure there will be single slot models of the 4770 as well...
  • flipmode - Tuesday, April 28, 2009 - link

    I've got mATX too. AMD needs to focus on providing the best possible cooling and not make compromises for mATX. And when these cards arrive with bad ass coolers that keep the chips cool, the noise down, and the case temps down, it is too bad they get looked on with scorn. The consumer made his/her bed when choosing a motherboard and case. And even still, this card, dual slot and all, will fit in an mATX setup.

    That's just my feeling. I am thrilled to see high quality coolers attached to a $100 card. That's wonderful!
  • PrinceGaz - Wednesday, April 29, 2009 - link

    I agree. Far from not liking a dual-slot cooler, I love them. Not only do they keep the GPU itself cooler, but they also improve the overall system airflow. Given the choice, I'd always pick a dual-slot cooler over a same priced card with a single-slot cooler.

    The only possible reason for choosing a single-slot cooler would be if you wanted to use the slot right next to the gfx-card, which means the already inferior single-slot cooler is made even worse because there is now another card sitting millimetres from the GPU fan.

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