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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  • iwodo - Tuesday, April 28, 2009 - link

    The GTS 250 is not doing too bad at all. It is an 55nm part and many years old.
    I am sure if Nvidia did some small tweaks to it and shrink it to 40nm and add GDDR5, it would be much more competitive if not better then 4770.
  • Veteran - Tuesday, April 28, 2009 - link

    Then it would be even more expensive.... + power consumption wouldn't change much because of GDDR5

  • quanta - Tuesday, April 28, 2009 - link

    According to PC Perspective review[1], it has only 8 ROPs, and would only have 16 texturing units instead of 32.

  • kevinkreiser - Tuesday, April 28, 2009 - link

    with the die shrink i was really hoping for a single slot card this time. seriously will we ever see decent single slot cards again? i know the other manufacturers like gigabyte and his have their designs slightly slimmer but the coolers are still too big to fit in a single slot.
  • frowny - Tuesday, April 28, 2009 - link

    I imagine it's because the number of people that hate dual slot GPUs is so miniscule that it doesn't make sense to cripple your card's factory clocks just to cater to them. You can always get a 4670 or other low-end card if you want one that's a single slot.
  • kmmatney - Tuesday, April 28, 2009 - link

    Well, after reading the reviews, I don't find the card terribly exciting, except for the low power levels. At $110, this card is more of a triumph for ATi than it is consumers. It is very cheap to make, with fewer pins for the 128-bit memory bus, and cheaper power circuitry. It's a nice card, and overall the best card at it's price point, but just barely. The main prupose of this card was to be more profitable for ATi, and it's done a great job at that.

    A low cost HD4830 is a better deal for many people. It can easily overclock to HD4850 speeds (you have to go higher than actual HD4850 speeds to get the same perforamnce, due to the lower number of shaders). Also, there are 800SP HD4830 cards out there (or so I've heard).

    The mood I get from the AT article - ho hum, and that's my impression as well. The low power draw is very nice, though (see the XbitLabs article for the actual power draw of the card, instead of the whole system). It's very impressive in the power dept., but that's about it.
  • frozentundra123456 - Tuesday, April 28, 2009 - link

    good post. This is pretty much my feeling also, but you explained it better.
  • tomoyo - Tuesday, April 28, 2009 - link

    I think there's too much focus on the name of the video card. It's honestly perfect for the situation. They didn't rename an old gpu and it's obviously not the same type of chip as a 48xx. Also it's most certainly targeted for the midrange, which a 47xx sounds like a perfect name for. I'd say amd is doing a much, much better job at naming chips than nvidia, which has done far too many renames of the same chip.
  • Liujia - Tuesday, April 28, 2009 - link

    Hi,everyone,I come from China-mainland, nice to "meet" u all. Although I know anandtech for a long time, this's my first message in Anandtech. ^_^

    I'm glad to see that ATI becomes more and more stronger, she brings benign market competition,and gives us good performance/price low-end cards(actually not only card). that's really good for most chinese,because most young guys'earning ain't very much, just like me.....

    Due to previous high cost,not everybody owns PC in china, especially in rural areas,where occupy 80% population of china.....oh,god, can u image that how many computers we still need? We must energetically promote IT application and use IT to propel and accelerate industrialization & multi-media education in backward areas. Mr.Obama said:you still have a lot of work to do.
    so do we ^_^

    fortunately, right now:
    $20LE-1150+$30 690G(or maybe $50 780G)= waht a perfect entry level, for us.
    $50 4600+ $55 770 + $55 HD4650 = what a perfect middle level,for us.
    $120 X3 710 + $90 790GX + $95~120 HD4830/4850 = what a perfect player level, for us.

    Here,I'd like to give my full support to HD4770.
    BTW,go~houston rocket~! haha
  • armandbr - Tuesday, April 28, 2009 - link

    To me the biggest issue with this card is the memory size.
    I heard there are going to be cards with 1 Gb of ram.
    I hope there will be.

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