Original Link: http://www.anandtech.com/show/2756



First things first: the Radeon HD 4770 is faster than existing 4800 series hardware (namely the 4830). Yes, this is by design.

We hate to start another article complaining about naming (there seems to be some sort of pervasive renaissance of poor naming this year), but let's talk about why exactly we are in this situation with a look back at something from our RV670 coverage:

At least it's ironic.

Yes, the problem is born out of AMD's attempt at sensible, appropriate naming. The problem is that AMD seems to want to associate that "family" number with the physical GPU than with the a performance class. This is despite the fact that they generally use increasing numbers for "families" that are generally faster. Thus, the 40nm RV740 needs a new family name, and they can't really choose 49xx presumably (by us) because people would be more upset if they saw a high number and got lower performance than if they saw a lower number and got higher performance. So Radeon HD 4770 it is.

When we brought up our issues with the naming scheme, AMD was quick to respond that naming is one of the most contentious things that go on in bringing a graphics card to market. People get passionate about the issue. Passion is great, but not if it confuses, misleads, or distracts the end user. And that's what a decision like this does. There is no practical reason that this card shouldn't be named 4840 to reflect where it's performance falls. After all, the recently released 4890 is host to quite a few tweaks to the physical layout of the chip and it isn't called the 4970.

At the same time, that trailing zero is doing nothing on all AMD hardware. There is an extra number in there that could allow AMD to shift some things around in their naming scheme to retain all the information they want to reflect about architecture generation, processes revision, performance class and specific performance within that class. If we are going to have a model number system, in order to have real value to both the informed and casual graphics card user it needs to be built to properly represent the underlying hardware AND be strictly related to performance. With this move, AMD joins NVIDIA in taking too many liberties with naming to the detriment of the end user.

Now that that's taken care of, what we have today is a 40nm GPU (the first) paired with 512MB of RAM on a $110 card. The package delivers performance at a level between the 4830 and the 4850. First indications were that this would be a $99 part and the performance we see with this card at the "magic" price would be terrific. It's still not bad at a 10% higher price. AMD had indicated that there should be some $10 mail in rebates available for those who are interested in the extra bonus hassle and upfront cost to get the cash.



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.



Age of Conan Performance

For our first test, the Radeon HD 4770 actually leads the pack. Now, we can't be sure this is all hardware, as we are using two different drivers for the AMD hardware. It could be that some architectural enhancement helped boost performance, but it is more likely that the difference in the driver revisions we are using is what causes this jump in performance. Whether this is a driver level improvement or some hardware tweak, this is a pretty impressive performance.

Regardless of the cause, looking at competitive data shows that the Radeon HD 4770 has a clear advantage over NVIDIA hardware in Age of Conan. This is nothing new, as AoC favors AMD hardware. We will be moving to the DX10 version in future articles, and that might shake things up a bit.

Age of Conan




Call of Duty Performance

This is the game that NVIDIA leads in. Clearly the 9800 GT can't keep up even when its architecture has an advantage, but the GTS 250 makes short work of the 4770.

Call of Duty World at War




Crysis Performance

This one is essentially a tie between the 4770 and the GTS 250. The NVIDIA hardware maintains a slight lead at 1920x1200, but at an unplayable framerate so the slight edge is bittersweet. 

Crysis Warhead

 




Fallout 3 Performance

This test is similar to Crysis in that the competing hardware essentially ties. The AMD part has a slight advantage at the highest resolution, but this time it seems fairly playable.

Fallout 3




Far Cry 2 Performance

The Radeon HD 4770 puts in another good showing here, tying the 4850 and leading the competition. This is where things start to become clear. The Radeon HD 4770 is stacking up to look like the part to get near this price point.

FarCry 2




Race Driver GRID Performance

The fact that the AMD hardware is leading here is not unexpected. But we do see that the NVIDIA GTS 250 looks a little bit CPU bound at lower resolutions.

Race Driver GRID




Power Consumption

The Radeon HD 4770 shows a solid mix of low idle and load power clearly outclassing the NVIDIA hardware. The relatively small differential between the two is interesting especially considering the kind of performance we see.

Idle Power


Load Power



Final Words

And there you have it: 40nm has arrived, and it looks pretty good. The Radeon HD 4770 always outperforms the older 4830 and sometimes gives the 4850 a run for its money.

As for the competition, the 4770 comes out on top in the games we tested. The more expensive GTS 250 leads in Call of Duty World at War, while the 4770 blows the doors off everything in Age of Conan. As for the other benchmarks, they come out pretty close with the 4770 generally ahead. But the clincher is Far Cry 2 performance which shows the Radeon HD 4770 leading the GTS 250 fairly well in a heavy hitting graphics engine.

Our expectations for the hardware were a little higher while our idea of price was also a little lower, but from our perspective, the extra $10 isn't out in left field as this card generally leads a competitive part that costs even more and sometimes pushes up toward the Radeon HD 4850. At the same time, you can spend a little bit less and get some very good performance if you are into the value option.

We still don't like the fact that the AMD decided to name this the 4770 despite the fact that it consistently outperforms the 4830. Unfortunately, we can't do any more about it than we are already doing. So we'll have to make do in the meantime.

NVIDIA should have 40nm parts out this year as well, and both camps have their own way of rolling out new process technology. AMD continues to be a little bit more aggressive on that front, seemingly making the move on the earliest viable hardware whether it's low or high end. NVIDIA looks to play it a little more cautiously. It's all about cost benefit. Certainly it's a benefit to have smaller GPUs as they cost less to make. But early on in the life of a manufacturing process, yields can suffer driving price up. Timing the move well can have its advantages, and NVIDIA is counting on that this time around.

It isn't clear when NVIDIA will have a part in this generation of their architecture that competes in the near $100 market. For now, the best option is clear: the Radeon HD 4770 is the way to go.

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