by Alexey Stepin , Yaroslav Lyssenko, Anton Shilov
07/04/2008 | 06:01 PM
The announcement of the ATI Radeon HD 4800 architecture has enabled AMD’s graphics department to claim technological superiority after a long while. The developer has proved he is not only alive and well but has plenty of resources to develop best-in-class graphics solutions.
As a dramatic change in the company’s development strategy, ATI now focuses on creating mainstream rather than ultra-performance top-class GPUs. The RV770 processor, the heart of the new ATI Radeon HD 4800 series, has been created according to this new strategy.
Within ATI’s approach, increasing the new chip’s performance must be accompanied with a meticulous optimization of its architecture. It may sound paradoxical, but developing a best-in-class mainstream GPU that would combine high performance with low power consumption is a more difficult task than developing a new monster of the ultra-high-end class. Why? Because in the latter case you can just increase the computing resources of the chip without caring much about its power consumption, amount of transistors, size, and other factors that are not directly linked to 3D performance. This is in fact the general approach Nvidia followed while developing its GT200. Of course, the company could not avoid the problems associated the incredible complexity of the chip. The chip turned out to be huge. Consequently, there are fewer dies that can be made out of one standard silicon wafer. The yield of such complex chips is rather low, which explains the high cost of the new chip.
ATI’s developing team, on their part, did their job right and the RV770 is a true realization of the evolutionary ideas brought to the point of perfection. As our theoretical tests showed, the junior graphics card with the new GPU boasts a higher potential than the Nvidia GeForce 9800 GTX. And the Radeon HD 4850 comes at a recommended price of $199 whereas the competing solution was selling for $349 just recently!
Still, theoretical tests can only give you a hint about the performance of a graphics solution. Gamers are more interested in real games. This review is going to fill you in on that matter. The Radeon HD 4850 and 4870 cards will be tested in our standard selection of benchmarks including 15 games and two benchmarking suites from Futuremark.
To check out the practical potential of the new ATI Radeon HD 4850/4870 and compare their performance against that of the previous generation ATI and Nvidia graphics accelerators we put together the following testbed:
According to our testing methodology, the drivers were set up to provide the highest possible quality of texture filtering and to minimize the effect of software optimizations used by default by both: AMD/ATI and Nvidia. Also we enabled transparent texture filtering. As a result, our ATI and Nvidia driver settings looked as follows:
For our tests we used the following games and synthetic benchmarks:
First-Person 3D Shooters
Third-Person 3D Shooters
We selected the highest possible level of detail in each game using standard tools provided by the game itself from the gaming menu. The games configuration files weren’t modified in any way, because the user doesn’t have to know how to do it. The only exception was Enemy Territory: Quake Wars game where we disabled the built-in fps rate limitation locked at 30fps. Games supporting DirectX 10 were tested in this particular mode.
Besides ATI Radeon HD 4850 and ATI Radeon HD 4870 we have also included the following graphics accelerators to participate in our test session:
The tests were performed in the following resolutions: 1280x1024/960, 1600x1200 and 1920x1200. If the game didn’t support 16:10 display format, we set the last resolution to 1920x1440. We used “eye candy” mode everywhere, where it was possible without disabling the HDR/Shader Model 3.0/Shader Model 4.0. Namely, we ran the tests with enabled anisotropic filtering 16x as well as MSAA 4x antialiasing. We enabled them from the game’s menu. If this was not possible, we forced them using the appropriate driver settings of ATI Catalyst and Nvidia ForceWare drivers.
Performance was measured with the games’ own tools and the original demos were recorded if possible. Otherwise, the performance was measured manually with Fraps utility version 2.9.1. We measured not only the average speed, but also the minimum speed of the cards where possible.
This game doesn’t support display resolutions of 16:10 format, so we use a resolution of 1920x1440 pixels (4:3 format) instead of 1920x1200 for it.
The ATI Radeon HD 4850 lays claim to leadership in its class right from the start. It is somewhat slower than the Nvidia GeForce 9800 GTX, but the difference in average frame rate is a mere 6% at 1920x1200, for example, while the minimum speed is the same. It means both cards provide the same level of playing comfort while the ATI Radeon HD 4850 is far easier to use because it is smaller and doesn’t need two power connectors.
The game is not new and doesn’t utilize the powerful computing capacities of the new core. This is the reason why the ATI Radeon HD 3870 X2 is faster, but this interesting dual-processor solution from ATI is living its last days. As you can see, the Radeon HD 4870 is about as fast as the dual-processor card while having only one GPU. The idea of installing two GPUs on one PCB is still alive, though. Being one of the cornerstones of ATI’s new strategy, it will be embodied in the ATI Radeon HD 4870 X2 which is going to become a real champ among single graphics cards.
BioShock doesn’t support FSAA when running in Windows Vista’s DirectX 10 environment. We benchmark graphics cards without FSAA in this game.
The Radeon HD 4850 is somewhat slower than the GeForce 9800 GTX at 1280x1024. At the higher resolutions the new card is just as fast as Nvidia’s monster. Not knowing exactly the reason, we suppose it is due to the new memory subsystem, particularly the caches, as well as to the improved architecture of the rasterization units.
The Radeon HD 4870 beats the GeForce 9800 GTX easily, setting a new record – over 100fps at 1600x1200. Obviously, the Nvidia GeForce 9800 GTX+ with increased frequencies won’t make a good rival to it whereas the Nvidia GeForce GTX 260 is considerably more expensive.
Despite all the architectural improvements the ATI Radeon HD 4850 is unable to catch up with the Radeon HD 3870 X2. The Radeon HD 4870 overtakes the latter only at 1600x1200 thanks to super-fast GDDR5 memory. It’s hard to explain these results. The new cards from the Radeon HD 4800 series are only inferior to the Radeon HD 3870 X2 in terms of raster back-ends, surpassing it in everything else.
However, the results are in favor of ATI’s new strategy which implies offering multiprocessor solutions for the top-end sector. Judging by the results of the Radeon HD 3870 X2, we can suppose that the Radeon HD 4870 X2 is going to ensure comfortable performance in Call of Juarez at resolutions above 1280x1024.
That’s a triumph of the RV770 chip: the Radeon HD 4850 begins with outperforming the GeForce 9800 GTX by 5% at 1280x1024 and then leaves it as far as 23-27% behind! The Radeon HD 4850 can maintain an average frame rate of nearly 60fps at 1920x1200, which is the optimal speed for first-person shooters. It’s like David beating Goliath! The Radeon HD 4870 is even more impressive: 50% ahead of the GeForce 9800 GTX at 1600x1200 and over 50% ahead at 1920x1200!
This game is tested at the High level of detail, excepting the Shaders option which is set at Very High. This way we try to achieve a compromise between image quality and speed.
The Radeon HD 4850 is not brilliant here, but the 17% gap from the GeForce 9800 GTX at 1280x1024 is not a big problem as both cards are far from delivering comfortable performance. The ATI Radeon HD 4870 shows a much better result and is even faster than Nvidia’s card at high resolutions, but doesn’t add any more comfort. Still, this is another victory for ATI.
Perhaps the performance of the new cards in this game can be improved by Catalyst updates, but the real breakthrough should occur with the Radeon HD 4870 X2. We’ll check this out in our upcoming review that will cover new CrossFireX tandems.
The frame rate is fixed at 30fps in this game as this is the rate at which the physical model is being updated at the server. Thus, this 30fps speed is the required minimum for playing the game.
ATI’s solutions have never been good in this test but the Radeon HD 4850 breaks this tradition. Being a junior model of the new series with a price tag of only $199, it easily competes with the GeForce 9800 GTX that cost over $300 just recently.
The senior model, Radeon HD 4870, leaves Nvidia’s card far behind. ATI’s new development approach works perfectly best here: not relying on the sheer increase of GPU resources, the developer complements it with topology and architecture optimizations as well as latest technological advances such as GDDR5.
The Radeon HD 4850 doesn’t beat the GeForce 9800 GTX in this test, but delivers comfortable performance in every tested resolution. The new card is also ahead of the Radeon HD 3870 X2 in the first two display modes, which is an achievement considering how different these solutions are in terms of price, power consumption and heat dissipation.
The Radeon HD 4870 nearly overtakes the GeForce 9800 GTX: the gap amounts to 2-5% depending on the resolution. That’s a negligible difference.
The game doesn’t support FSAA when you enable the dynamic lighting model, but loses much of its visual appeal with the static model. This is the reason why we benchmarked the cards in S.T.A.L.K.E.R. using anisotropic filtering only.
S.T.A.L.K.E.R. is optimized for Nvidia’s architecture and ATI can do nothing about it. The Radeon HD 4850 is good enough at 1280x1024, though.
The Radeon HD 4870 ensures a good speed at 1600x1200 thanks to its fast memory but loses to the Radeon HD 3870 X2 at 1920x1200, having a very low minimum of speed. However, it is clear that the new Radeon HD 4800 architecture is strong enough to be competitive even in unfriendly environments, i.e. in games that are optimized for Nvidia’s GPUs.
It is only on Nvidia’s SLI solutions, including the GeForce 9800 GX2, that this game used to run fast enough at the maximum settings, but now the Radeon HD 4850 comes into play, conquering the resolution of 1280x1024 and outperforming the GeForce 9800 GTX by 40%. You won’t have to lower the level of detail on the new graphics cards if you play at that resolution.
Why is the RV770 so fast in this test? The new core contains a lot of architectural optimizations but seems to benefit the most from the 40 texture processors. It is clear that the memory bandwidth doesn’t limit the speed because the Radeon HD 4870 is only 15% ahead of the junior card at 1920x1200. When the display resolution is so high, the memory bandwidth usually becomes an important factor irrespective of the game engine.
The ATI Radeon HD 4850 loses to the GeForce 9800 GTX in this test although ensures a comfortable speed in every display mode. It is competitive against the GeForce 8800 GT 512MB, so that’s not a total defeat. The more advanced Radeon HD 4870 is behind the GeForce 9800 GTX at first but overtakes the opponent at 1920x1200 thanks to higher memory bandwidth.
The Radeon HD 4850 shows its best in this test, leaving the GeForce 9800 GTX far behind and even outperforming the Radeon HD 3870 X2. The frame rate is quite high for playing at 1600x1200 and 1680x1050. Until today you could only get this speed from a SLI subsystem or a GeForce 9800 GX2 that cost quite a lot. ATI’s new card is obviously a success as its price is a modest $199.
The senior model of the new series takes first place but it is not far ahead of the junior model. It doesn’t make new display modes available for the gamer because its minimum speed doesn’t reach the desired 25fps at 1920x1200.
The game loses much of its visual appeal without HDR. Although some gamers argue that point, we think TES IV looks best with enabled FP HDR and test it in this mode.
The Radeon HD 4850 doesn’t set any records in this game which used to be a hard trial for the best graphics solutions at the time of its release, but now is hardly a problem for modern graphics hardware. The new mainstream card just shows its worth, equaling ATI’s previous-generation flagship and even delivering the best minimum speed in the open scenes. Thus, it is the preferred choice in its class for playing this game.
The difference between the Radeon HD 4850 and Radeon HD 4870 is small because the latter’s main advantage of fast memory is not called for in this game, at least if you prefer HDR to FSAA.
The new add-on to Company of Heroes is tested in DirectX 10 mode only since it provides the highest quality of the visuals.
The ATI Radeon HD 4850 is 10-12% slower than the Radeon HD 3870 X2 in terms of average frame rate but is close to the comfortable minimum of speed at 1280x1024. The GeForce 9800 GTX has a very low minimum of speed despite being 30% ahead of the new Radeon in average frame rate. Thus, the Radeon HD 4850 seems to be the better choice for this game.
The Radeon HD 4870 triumphs in this test. It is the first graphics card to ensure a comfortable minimum of speed at 1600x1200/1680x1050 and to get close to doing that at 1920x1200. It is a superb result, especially for a $299 card.
The add-on to C&C 3: Tiberium Wars brought no changes into the technical aspect of the game. The game still having a frame rate limiter, you should consider the minimum speed of the cards in the first place.
The Radeon HD 4850 and 4870 are faster than the GeForce 9800 GTX just because their minimum speed is 2fps higher at 1920x1200. This has no effect on the gamer’s experience, though. The GeForce 9600 GT is the only obvious outsider in this test.
The Radeon HD 4850 is 7% slower than the GeForce 9800 GTX at 1280x1024 but the latter has problems at the higher resolution. It is the common problem of all modern solutions from Nvidia – inefficient graphics memory management. The ATI card goes ahead as the consequence even though the overall performance level is too low for the game to be playable at the highest graphics quality settings. The Radeon HD 3870 X2 is close to delivering comfortable speed, so we can hope for even better results from the upcoming Radeon HD 4870 X2.
With the ongoing transition to DirectX 10, 3DMark06 loses its significance as an accurate tool for benchmarking modern graphics cards with unified architecture. However, the Radeon HD 4850 scores almost the same amount of points as the Nvidia GeForce 9800 GTX whereas the Radeon HD 4870 scores over 12,000 points, being only inferior to the Radeon HD 3870 X2.
It’s all clear when we check out the groups of tests. Despite the improvements in the texture-mapping section, the ATI Radeon HD 4850 is inferior to Nvidia’s solution in the Shader Model 2.0 tests but wins the SM3.0/HDR group. It is quite logical considering that the RV770 has inherited its main architectural features from ATI’s previous GPU. The Radeon HD 4870 on its part is slightly faster than the GeForce 9800 GTX even in the SM2.0 tests.
The first test result has improved considerably over the Radeon HD 3870 but the Radeon HD 4850 it is still 39% slower than the GeForce 9800 GTX. The two cards don’t differ much in terms of GPU clock rate, so it can’t be the reason. We can’t find an explanation because the theoretical tests suggest that the Radeon HD 4850 doesn’t feel a lack of texture processors. The Radeon HD 4870 can’t beat Nvidia on its turf, either, at least in the first test.
The second test is more favorable towards ATI’s cards which are glad to show their ability to process vertex shaders. The Radeon HD 4850 is inferior to the GeForce 9800 GTX by only 7-8% whereas the Radeon HD 4870 is 15% ahead of Nvidia’s card because transferring arrays of vertex data requires fast graphics memory.
The new cards have no rivals in the SM3.0/HDR tests, except for the Radeon HD 3870 X2 whose processors are working in AFR mode and rendering two sequential frames during the time the Radeon HD 4850 and 4870 do only one. Despite the use of SM3.0 and HDR these tests are not complex enough to load modern solutions by 100%.
To minimize the influence of the CPU on the 3DMark Vantage tests we select the Extreme profile that uses 1920x1200 resolution, 4x FSAA, and anisotropic filtering.
As opposed to 3DMark06, 3DMark Vantage uses all the GPU resources available. That’s why the ATI Radeon HD 4850 is ahead of the other cards, including the ATI Radeon HD 3870 X2. The only advantage of the latter card is that it has more rasterization subunits but they seldom play an important role in modern games. The Radeon HD 4870 enjoys an even bigger lead, being the first to score over 3,000 points.
Although the gaming tests of 3DMark Vantage are different, the Radeon HD 4850 and 4870 win both of them, which indicates the lack of bottlenecks in ATI’s new architecture. It easily copes with the math1ematics-heavy first test as well as with the high texture-mapping load of the second test. The Radeon HD 4850 is 31% and 25% ahead of the GeForce 9800 GTX, respectively. The recently released overclocked version of Nvidia’s card, called GeForce 9800 GTX+, is unlikely to close this gap. And there is no talking about any competition with the Radeon HD 4870.
The results of our ATI Radeon HD 4850 and 4870 performance tests revealed very high potential of these graphics cards. The youngest model, 4850, equipped with GDDR3 memory did show excellent results having set a new performance standard for sub-$200 mainstream graphics accelerators. It also proved capable of competing against solutions from a much higher price range.
The top model, 4870, won in majority of benchmarks. It is interesting that by comparing the gaming performance of the top and mainstream ATI Radeon 4800 solutions we can determine when memory subsystem bandwidth is most important for the end result.
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In 1280x1024 resolution most prizes were won by the “green team”, however, we can’t say that the “red team” lost: 4850 solution performed fast enough in most tests and in quite a few of them left the competitors behind. Namely, ATI Radeon HD 4850 performed best in Call of Juarez, Call of Duty 4, Lost Planet, Hellgate: London, and reached parity in Enemy Territory: Quake Wars. So, it makes 5 tests out of 15 with a slight lag in a few more – not bad at all, keeping in mind that the new ATI solution performed sufficiently fast in most cases. The only exceptions were especially resource-hungry games, such as Crysis, where none of our today’s testing participants managed to do well enough. Even the S.T.A.L.K.E.R. performance was not a big failure, even though this game is known to be extremely favorable to Nvidia hardware.
The top ATI Radeon HD 4870 model won in most benchmarks. It let Nvidia GeForce 9800 GTX get ahead only in Tomb Raider: Legend and TES IV: Oblivion, although the performance level in both these games remained high enough for comfortable gaming.
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As we san see, the new architecture shows its real best starting with 1600x1200 or more widely spread these days 1680x1050 resolution. In some cases ATI Radeon HD 4850 almost completely caught up with Nvidia GeForce 9800 GTX. Among these games are Battlefield 2142, BioShock, Crysis and TES IV: Oblivion. And it even became an indisputable leader in World in Conflict.
ATI Radeon HD 4870 was also as successful. In this resolution it won in 11 tests out of 15 and performed as fast as Nvidia GeForce 9800 GT in three more.
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The next resolution we will talk about is 1920x1200. Here ATI Radeon HD 4850 wins a few more victories, the most remarkable being Enemy Territory: Quake Wars, which is the OpenGL field where Nvidia solutions have usually been undefeated. It also took the lead in TES IV: Oblivion and Company of Heroes: Opposing Fronts. So, the final score makes 9:4 in ATI’s favor. In three more games ATI Radeon HD 4850 performs almost as fast as Nvidia GeForce 9800 GTX. In addition we should point out a remarkable victory the new ATI architecture won in 3DMark Vantage, and mention practically indisputable leadership of our ATI Radeon HD 4870 in this resolution.
Despite the fact that ATI Radeon HD 4850 belongs to the mainstream graphics accelerators, it is a truly powerful weapon. While it offers excellent gaming performance, its PCB design is fairly simple and inexpensive, so its price has every chance to go down a lot later on without any financial losses for ATI. Unfortunately, 110W power consumption (and heat dissipation) does not go well with a single-slot cooling system. So we would advise using a more efficient cooler or ensuring ideal ventilation of the system case.
ATI/AMD’s main competitor, Nvidia, is trying hard to save the situation by joggling the prices, however, it looks more like panic on a sinking ship rather than well-planned strategy. The thing is that Nvidia doesn’t have anything in their arsenal to respond with. GeForce 9800 GTX features much more complex design, because it was initially intended for $299+ price range. Therefore, Nvidia’s dramatic price drop may have been very painful from the financial standpoint for both Nvidia and partners. The top model in the new ATI Radeon HD 4800 lineup turns out to be completely alone out there: I doubt that the overclocked Nvidia GeForce 9800 GTX with a 55nm G92 GPU could really compete against it. Besides, extreme complexity of GeForce GTX 200 graphics cards will not let Nvidia reduce the prices without losing any money. At least not any time soon.
ATI Radeon HD 4850 deserves the prestigious title of the best graphics accelerator in the sub-$200 category. It provides very high performance at a comparatively low price and exceeds Nvidia GeForce 9800 GTX in a number of other aspects.
ATI Radeon HD 4870 is equipped with super-fast GDDR5 memory delivering impressive data transfer rate of 115.2GB/s even with 256bit bus. This solution performs extremely fast, which puts it next to more expensive GeForce GTX 260 and 280.
We have to say that unlike the competition, ATI Radeon HD 4800 supports DirectX 10.1 and features a more advanced UVD2 video processor. It also supports 7.1 HD sound over HDMI.