by Alexey Stepin , Yaroslav Lyssenko
04/01/2009 | 09:00 PM
‘Well, in OUR country,’ said Alice, still panting a little, ‘you'd generally get to somewhere else -- if you ran very fast for a long time, as we've been doing.’
‘A slow sort of country!’ said the Queen. ‘Now, HERE, you see, it takes all the running YOU can do, to keep in the same place. If you want to get somewhere else, you must run at least twice as fast as that!’
“Alice in Wonderland” by Lewis Carroll
Resting on the laurels is undoubtedly very pleasant but also very dangerous occupation. And it is twice as dangerous in the information technology field, including the gaming 3D graphics market. Just recall the confrontation between ATI Radeon 9700/9800/X800/X850 and Nvidia GeForce FX, when the former was at the peak of success for a long time and the latter couldn’t produce an adequate response without efficient graphics architecture available. Everything changed in a wink when Nvidia launched the world’s first GPU with Shader Model 3.0 support - NV40 (GeForce 6800), and then G70 (GeForce 7800). ATI solutions that looked so winning against the background of GeForce FX lost their appeal and the company had to catch up. Their first attempt, R520 (Radeon X1800) turned out not very successful. Only the second try, R580 (Radeon X1900/1950) became a worthy rival to the leader. However, Nvidia didn’t keep its hands in pockets either and soon responded with their new GeForce 7900 family.
After the launch of Nvidia G80 (GeForce 8800), ATI was behind the leader for quite some time. The announcement of R600 (Radeon HD 2900) turned out not very successful. As for its successor, RV670 (Radeon HD 3800), it was technologically more advanced, but still not fast enough to compete against high-speed Nvidia solutions. All it could do was help ATI stay afloat in those difficult days.
ATI’s eternal rival kept reaping the fruits of their labor, however, it was way too early to celebrate the final victory yet. And that was the exact same mistake ATI had made before. No wonder that June 25 2008 was a total shock for Nvidia. On that day ATI announced their new RV770 core that not only set new performance and price standards, but also overthrew the former leader to the outsider camp. At that time ATI had already long been graphics division of Advanced Micro Devices and their financial situation improved dramatically. Nvidia, on the contrary, started losing its territory making one mistake after another. Remember, for instance, how much they bet on a super-complex and extremely expensive G200 core.
However, by 2009 Nvidia already managed to fix most if their mistakes having launched a 55nm G200, and starting to offer simpler and cheaper graphics card modifications based on it. They even won back the title of the fastest graphics accelerator designer when they responded to the Radeon HD 4870 X2 challenge with their own high-end dual-GPU solution. Luckily, ATI was smarter this time: since they had excellent architecture that proved its technological advancement and marketing efficiency at their disposal, they decided to prevent any possible power seizure on Nvidia’s part by launching an enhanced version of their RV770 that could work at even higher frequencies.
This is pretty logical strategy keeping in mind that the gap between Radeon HD 4870 1GB and Radeon HD 4870 X2 has set in as pretty significant by now, because Radeon HD 4850 X2 that was intended to fill it in, hasn’t become popular among the graphics card makers. This gap was immediately taken over by Nvidia with their extremely successful GeForce GTX 285. Luckily for ATI, GTX 285’s retail price still remains pretty high, despite all Nvidia’s price cuts: they are way beyond $300, which works like a psychological threshold for many gamers.
In other words, there is real demand for a powerful graphics adapter priced below $300, even though it is still not as big as the demand for sub-$200 graphics solutions. Therefore, the launch of Radeon HD 4890 is a very timely and logical event that should prevent a dangerous counterattack on Nvidia’s part and help ATI keep the regained performance-mainstream gaming market territory. This new defensive weapon is based on the new RV790 graphics processor, which was officially launched on April 2nd. Our today’s review is going to talk about this new GPU and graphics cards based on it.
So what are the new ATI graphics cards actually like? Let’s take a closer look at their technical specifications:
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At first glance Radeon HD 4890 only differs from the predecessor, Radeon HD 4870, by the GPU and memory clock frequencies. However, if you take a closer look at the technical specifications above, you will see that RV790 has a few features distinguishing it well from the RV770 core. At least, it has 3 million more transistors and hence a 22sq.mm larger die. So what have they done?
Nvidia is not the only one who knows that the best is the enemy of the good. Successful graphics architecture hasn’t been changed since RV770. However, Advanced Micro Devices developers and engineers put a lot of efforts into making RV790 work stably at 850MHz frequency. They also did their best to lower the power consumption of the new GPU at least in idle mode.
When they designed RV790, they revised the entire RV770 internal structure quite significantly, having rebalanced internal chip timings and optimized its internal power circuitry. The memory controller now supports burst read, which was earlier implemented in RV710 and 730. But most importantly, they added a capacitor Decap Ring along the entire RV790 perimeter, which should improve the signal quality by lowering the parasitic noise. As the clock frequency increases, the influence of this noise on the GPU and memory stability becomes more and more serious. All these measures called for more transistors within the new core. However, in fact, RV790 became only 0.3% more complex, which is a really small price to pay for the ability to work at 850MHz+ frequencies.
Note that it is for the first time in history of consumer 3D graphics that one of the graphics giants announced their new product in two official incarnations: regular and overclocked. It is usually the launch partners who roll out overclocked graphics card modifications, but in this case Radeon HD 4890 is really announced twice: as a Radeon HD 4890 with 850MHz core and as a Radeon HD 4890 OC with the core clock starting at 900MHz. The important thing is that the latter is under full official Advanced Micro Devices support. These graphics cards will most likely be manufactured with specially selected RV790 GPUs that are guaranteed to work at 900MHz+. The actual technical specs of the product will depend on the maker, so we will most likely see elite Radeon HD 4890 OC solutions that will be able to reach 1000MHz GPU and 1250 (5000MHz) MHz memory frequencies, especially since GDDR5 memory chips with these characteristics are available from Qimonda, Hynix and Samsung. It is important that both Radeon HD 4890 models will be available in mass quantities right after the official launch. The advantage here is on ATI’s side, because Nvidia is going to start selling its alternative, GeForce GTX 275, only on April 14 – almost 2 weeks after the launch.
The first batch of Radeon HD 4890 and Radeon HD 4890 OC will include only solutions using reference PCB design and cooling systems. However, in the near future we will undoubtedly see unique products based on proprietary layouts from the large graphics card makers, such as Asustek Computer or Gigabyte Technology.
The first solution on the new ATI GPU was the Radeon HD 4890 OC from Tul Corporation branded as PowerColor HD4890 Plus. We are going to use it as an example to study all peculiarities of the new product from Advanced Micro Devices launched today.
This solution will ship to retail channel in a relatively compact vertical box with “fantasy” design theme. There is nothing extraordinary about this design, but it is overall very attractive, at least thanks to no flagrant colors:
There is not too much info on the package. Among the useful facts for the user, we should mention the video memory size and type. The “plus” word is a sticker, which will allow using the same exact box for the regular Radeon HD 4890 and for the overclocked Radeon HD 4890 OC graphics cards.
Unlike most similar packages, the outer box is not a thin slip-cover, but is made of thick multi-layer cardboard. Nevertheless, there is another solid box inside that holds the graphics card and accessories. Unfortunately, we received a pre-production sample, so there was only a brief installation guide in several languages including Chinese, Korean, Japanese and Greek.
Of course, PowerColor HD4890 Plus will be selling with a much richer accessories bundle including all necessary cables, adapters and disks with drivers and software.
For the reasons described above, we can’t say anything about the accessories bundle, but the package looks very good. There is nothing extraordinary about it, but it looks appealing, is compact in size and convenient to handle.
Being a revised RV770, the new graphics core RV790 is, however, not pin-compatible with its predecessor and made it necessary to develop a new PCB for the Radeon HD 4890 series. The PCB is of unified design, i.e. the same for both: the regular and OC versions of the new card.
The new products resemble the ordinary Radeon HD 4870, the family traits being perfectly visible even with the cooling system removed. There is indeed no reason for ATI to abandon its successful design solutions that can be reused to save time, resources and money. However, there are quite a number of significant differences, mostly concerning the GPU and memory power circuits. These parts of modern graphics cards are revised the most often.
So, the power circuitry of the Radeon HD 4890 has been reinforced to seven phases. The two top phases with single-channel PA0511 inductors and compact power drivers seem to be responsible for GDDR5 memory whereas the other five phases, with advanced power components and an assemblage of dual- and triple-channel PA1312NL and CPLA-3-50 inductors, power the graphics core. For comparison, the Radeon HD 4870 had a three-phase GPU voltage regulator with a possibility of expanding to four phases. The more complex power circuit is necessary as the Radeon HD 4890 is specified to have a peak power consumption of 190 watts.
The power circuit is controlled by two Volterra VT1165MF controllers. These chips allow to adjust the GPU voltage from software. It is for VT1165-based cards that EVGA has released its GPU Voltage Tuner program, so there seem to be no theoretical obstacles to creating a similar tool for the Radeon HD 4890.
Despite the increased capacity of the GPU voltage regulator, this Radeon HD 4890 OC series product carries a couple of ordinary 6-pin PCIe 1.0 connectors with a max load capacity of 75 watts. The bottom seat has two additional pins and can be used to install an optional 8-pin PCIe 2.0 connector. But to all appearances, the power consumption of the RV790 is not as high as we expect. We will check this supposition out in the appropriate section of the review.
PowerColor HD4890 Plus carries eight GDDR5 chips manufactured by Qimonda. They are placed in an L-shaped pattern around the GPU. Marked as IDGV1G-05A1F1C-40X, these chips have a capacity of 1 gigabit (32Mb x 32) and a voltage of 1.5V. The 40X suffix indicates a rated frequency of 1000 (4000) MHz but the company also offers faster GDDR5 memory that is able to work at frequencies up to 1250 (5000) MHz. The memory frequency of the PowerColor HD4890 Plus equals that of the reference card – 975 (3900) MHz. With a 256-bit memory bus this ensures a peak memory bandwidth of 124.8GBps. It would take a far more complex and expensive PCB design with a wider memory access bus to achieve a comparable bandwidth with GDDR3 memory. We also have to remind you that the memory controller has been slightly revised for RV790 and now supports burst read mode which was previously implemented in the RV710 and 730 cores.
Although the transistor count has increased but slightly in the RV790, from 956 to 959 millions, the die has become larger due to the ring of capacitors encircling the core. This solution helps eliminate parasitic noise from the signals and increase the frequency potential of the new chip. The GPU marking is still incomprehensible for the uninitiated. You can only learn the manufacture date from it. Here, it is the eighth week of the current year. It means that AMD has had working samples of RV790 since mid-February. The number 215 may refer to the chip’s frequency potential as in Nvidia’s GPU markings, but that’s just our supposition.
Like before, the die package is equipped with a protective metallic frame. As opposed to Nvidia, ATI still shuns the design with a heat-spreading cap. An extra thermal transition in the die – thermal interface – heat-spreader chain would not be good for a core which is already far from cool.
The latest version of CPU-Z knows the RV790 and even tells the die size correctly, but cannot report its revision and provides an incorrect transistor count. It is a Radeon HD 4890 OC, so the core frequency is increased to 900MHz. The ordinary (without “OC” in the name) version has nominal core frequency of 850MHz. We don’t think this difference is going to be significant in 3D applications because both versions have the same memory clock rate.
The new core has retained the old design with 10 SIMD units each of which incorporates 16 superscalar execution modules, 4 texture processors, a dedicated L1 cache, and control logic. Each execution module consists of five ALUs, one of which is capable of executing complex instructions, a branch control unit, and a set of general-purpose registers. The total amount of ALUs is 800, just as before. Four raster back-ends, equivalent to 16 classic ROPs, are responsible for rasterization operations including hardware FSAA resolve.
Radeon HD 4890 has the same interfaces as its predecessor. In its standard configuration it is equipped with two dual-link DVI-I ports supporting up to 2560x1600 resolutions and audio-over-HDMI (with adapter). A 7-pin mini-DIN port offers support for analog video output in S-Video, Composite and YPbPr formats. And finally, two CrossFire interfaces allow uniting up to four Radeon HD 4890 cards into a single CrossFireX subsystem.
The described product is equipped with a reference cooler, so everything we will say below refers to every other reference-design Radeon HD 4890.
The reference cooler of the Radeon HD 4870 card is far from being an etalon in terms of noise and efficiency, yet the Radeon HD 4890 developers have employed it with but minor improvements. The cooler implements the same concept as Nvidia’s reference coolers but, unlike them, has a much smaller heatsink.
The cast aluminum frame is not connected with the main heatsink mechanically or thermally and only serves to dissipate the heat from the power circuit elements and memory chips. It is also the basis the fan and the plastic casing are fastened to. The frame has a strip of some green fiber material at the places of contact with the voltage regulator’s power drivers and multilayer elastic pads for the memory chips.
A rather small heatsink consisting of thin aluminum plates is installed on the massive copper base that contacts with the GPU die through a layer of dark-gray thermal grease. It is connected to the base with three heat pipes: one pipe more than in the Radeon HD 4870 cooler. The heatsink is cooled by a 12W blower CF1275-B30H-C004 from NTK Technologies which is very loud at maximum speed. As usual, the hot air is exhausted out of the system case through the slits in the graphics card’s mounting bracket.
The base of the cooler is fastened to the PCB with ten screws. The GPU heatsink is fastened separately with four threaded poles and a stiff X-shaped metallic back-plate with spring-loaded screws. There can be no misalignment that might damage the GPU die. Moreover, the heatsink cannot be accessed from the outside – it is covered by the plastic aerodynamic casing.
At first glance, the cooling system we have just described seems to be good, but we think the heatsink is rather too small for an RV790. We have apprehensions that the fan may have to work at a high speed to keep the temperature low. We will check this out in the next section of the review, though. And we also hope that graphics card makers will come up with alternative and better coolers for their versions of Radeon HD 4890.
The Radeon HD 4890 has rather ambiguous specified power requirements. On one hand, its peak power consumption has grown from 160 to 190W in 3D applications but on the other hand, its 2D consumption is lower than that of its predecessor. We checked this out on our special testbed configured like follows:
Following our standard procedure, the 3D load was created by the first SM3.0/HDR test from 3DMark06 running in a loop at 1600x1200 with forced 4x FSAA and 16x AF. The 2D load was emulated by the 2D Transparent Windows test from PCMark05. The PowerColor HD4890 has a pre-overclocked core frequency, so we had reduced it to the standard 850MHz in Catalyst Control Center before the test.
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ATI’s new product surprised us really. It is far more economical in 2D mode than its predecessor, but also consumes 10W less than the Radeon HD 4870 under load! This result was repeatable with a variation within 0.7W. So, the card’s peak power draw was never higher than 121W! The innovations in the RV790 design such as the decoupling circuitry and the revised internal power distribution system are very beneficial for the not-quite-economical RV700 architecture. The distribution of load among the individual power lines has changed considerably since the Radeon HD 4870. The load on the internal +12V line has lowered but the load on the bottom power connector has grown up. Following Nvidia, ATI has improved the algorithm for automatic reduction of the GPU frequency in 2D mode. In this case the GPU frequency goes down not to 300MHz as it used to before, but even lower, to 240MHz. The memory frequency in this case remains intact.
Generally speaking, 120.3 watts is not a record. It is better than the result of the GeForce GTX 285 but far worse than the power consumption of the GeForce GTX 260 Core 216. The power consumption of the GeForce GTX 275 is expected to be somewhere in between and comparable to that of the Radeon HD 4890.
Surprisingly enough, the Radeon HD 4890 was not very hot. The GPU temperature varied from 55 to 68°C only. For comparison, the core of the Radeon HD 4870 could be as hot as 90°C under load! The numbers indicate an improvement in the power efficiency of the RV790 processor, but what about the cooler’s noise?
The reference point of our noise test is 43dBA. This is the amount of noise at a distance of 1 meter from the working testbed equipped with a passively cooled graphics card. When we installed our Radeon HD 4890, we got the following results:
The card is very noisy when you turn the system on, but then drops the fan speed to near-silent level. The fan accelerates as the GPU load increases, making the card audible in the noise produced by our testbed which is not quiet by itself. It is mostly a characteristic rattle that must have been produced by the fan’s bearings. Anyway, we must admit that the Radeon HD 4890 is quite comfortable in terms of noisiness. Its cooling system behaves like the one of the Radeon HD 4870. Not a surprise considering that they are almost identical.
The official guide to overclocking the Radeon HD 4890 suggests to set the fan speed slider at 100% in Catalyst Control Center.
Well, this guide must be intended for deaf computer enthusiasts because if you follow the advice, the card sets the record of producing the highest noise we’ve ever heard in our tests. Over 64dBA at a distance of 1 meter from the system case is too much to be near the computer for a long time unless you wear protective earpieces.
We don’t think anyone will use the guide’s recommendation and so we ignored it in our overclockability test. We tested the Radeon HD 4890 with its fan management system set to automatic mode. Despite this, we achieved an impressive result on our first attempt.
Without using any additional overclocking tools or methods we conquered the 1GHz peak! For example, we had had to volt-mod the much simpler Radeon HD 3870 and increase its GPU voltage from 1.3V to 1.71V in order to achieve the same clock rate. The memory chips were stable at 1200MHz, which is equivalent to 4800MHz for GDDR5 memory. ATI’s initiative of launching the Radeon HD 4890 OC as an individual product makes sense indeed. The new card boasts excellent overclockability and full stability. It worked without problems at the increased frequencies and passed all of our tests. Therefore we will publish the test results it achieved at both default and overclocked frequencies.
We are going to investigate the performance of Radeon HD 4890 graphics card on our universal testbed with the following configuration:
The graphics card drivers were configured in the same way as before: to provide the highest possible quality of texture filtering and to minimize the effect of default software optimizations. As a result, our ATI and Nvidia driver settings looked as follows:
The list of benchmarks includes the following gaming titles and synthetic tests:
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 ordinary user doesn’t have to know how to do it. We made a few exceptions for selected games if that was necessary. We are going to specifically dwell on each exception like that later on in our article.
Besides PowerColor HD4890 Plus we have also included the following graphics accelerators to participate in our test session:
Since it is the first Radeon HD 4890 that we have received so far, PowerColor graphics card was tested as a regular non-overclocked model (without the “OC” in the name) at 850/975 (3900) MHz frequencies and at maximum overclocked speeds of 1000/1200 (4800) MHz.
We ran our tests in the following resolutions: 1280x1024, 1680x1050, 1920x1200 and 2560x1600. Everywhere, where it was possible we added MSAA 4x antialiasing to the standard anisotropic filtering 16x. We enabled antialiasing from the game’s menu. If this was not possible, we forced them using the appropriate driver settings of ATI Catalyst and Nvidia GeForce drivers.
Performance was measured with the games’ own tools and the original demos were recorded if possible. We measured not only the average speed, but also the minimum speed of the cards where possible. Otherwise, the performance was measured manually with Fraps utility version 2.9.8. In the latter case we ran the test three times and took the average of the three for the performance charts.
Starting with 1.3 version of this game it is possible to record and playback demos. Unfortunately, the minimal fps rate is not recorded in this case.
The new card has a good start. Even at a core frequency of 850MHz it is far ahead of the more expensive GeForce GTX 285 at resolutions up to 2560x1600. Nvidia’s card is only better at the highest resolution where memory bandwidth is the crucial factor. But when overclocked, the Radeon HD 4890 has no rivals, being second only to the dual-processor Radeon HD 4850 X2.
Comparing the Radeon HD 4870 1GB and the Radeon HD 4890, the latter is 9 to 13% faster at a core frequency of 850MHz.
The new Radeon HD 4890 equals the GeForce GTX 285 at the first two resolutions and outperforms the latter at 1920x1200 and 2560x1600. When overclocked, it is even better than the Radeon DH 4850 X2, yet its bottom speed is still not comfortable in this highly demanding game. The maximum performance growth over the predecessor is 15.5%.
We disabled the integrated frame rate limiter in the game console for the sake of comparing the cards. The game’s built-in benchmarking options do not provide information about the bottom speed, so there is no such info in the diagrams.
The Radeon HD 4890 is slower than the more expensive GeForce GTX 285 at three out of the four tested resolutions, but equals the latter at 1920x1200. Moreover, it easily delivers a playable frame rate even at the highest display mode. When working at overclocked frequencies, it is faster than Nvidia’s solution and occasionally faster than the Radeon HD 4850 X2.
Oddly enough, the Radeon HD 4890 is no better than its predecessor at 1280x1024, notwithstanding the higher core and memory frequencies. The difference can be observed at the higher resolutions, though. The gap grows from 7% at 1680x1050 to a serious 18% at 2560x1600. It is a noteworthy fact that the bottom speed of the Radeon HD 4890 is higher than that of the Radeon HD 4850 X2 in this game, especially at 1920x1200.
It is also interesting that overclocking ensures a hefty increase in the new card’s bottom speed. It nearly reaches a comfortable level at 2560x1600 whereas the same card has a bottom speed of only 9fps at that resolution without overclocking.
Unfortunately, ATI’s new product cannot deliver a playable speed at 2560x1600 even when overclocked, but performs well enough in the lower display modes. It offers an 11 to 14% growth of average performance relative to the Radeon HD 4870 1GB. It is also not much slower than the GeForce GTX 285 at resolutions up to 1680x1050 inclusive and will make a good buy for people who have 22-inch or smaller monitors.
The game runs on the Source engine and has an integrated benchmark, but the latter does not report the bottom speed information.
Thanks to the optimized internal architecture and higher clock rates, the Radeon HD 4890 offers a 10-15% growth of speed, which is enough to compete with the GeForce GTX 285 and even Radeon HD 4850 X2. On the other hand, the Radeon HD 4890 doesn’t offer anything new for a practical gamer because its predecessor could already provide a comfortable speed in Left 4 Dead at 2560x1600.
To achieve a playable speed in this game we disabled FSAA and such resource-consuming options as Sun rays, Wet surfaces and Volumetric Smoke. We use the Enhanced full dynamic lighting (DX10) mode for our test and additionally enable the DirectX 10.1 mode for the ATI cards.
The Radeon HD 4890 is only 6-12% ahead of the Radeon HD 4870 1GB but that’s enough to beat the GeForce GTX 285. Our overclocking even makes the card the overall leader, yet it still does not achieve an acceptable bottom speed at 1920x1200. Well, no other graphics solution, not even the Radeon HD 4850 X2, can do that.
The Radeon HD 4890 is 5-7% faster than the Radeon HD 4870 1GB at the default frequencies and 17-22% faster at the overclocked frequencies. The game is not very demanding, though. The new card can easily ensure comfortable gameplay at 2560x1600 without any overclocking.
The ordinary Radeon HD 4890 is not much better than the Radeon HD 4870 1GB in this test, but the picture is different when you unleash its huge overclocking potential. The overclocked 4890 beats the GeForce GTX 285 and also raises the bottom speed to comfortable level at 1920x1200. That’s very nice for a solution priced at less than $240.
The non-overclocked Radeon HD 4890 is superior to the GeForce GTX 285 at every resolution. When overclocked, it is competitive to the noisy and voracious monster Radeon HD 4850 X2. This game is optimized for ATI’s graphics architecture.
The new card enjoys a 7-10% advantage over the predecessors depending on the resolution. Overclocking adds another 5-11% to it. Not bad, but it is not enough to open any new gaming horizons, although provides comfortable minimum gaming performance with forced FSAA 4x in 1280x1024. I would like to point out that Mass Effect game initially doesn’t support antialiasing, so forcing it in the drivers doesn’t provide any serious image quality improvement because of actively utilized post-processing algorithms.
The Radeon HD 4890 is faster than the GeForce GTX 285 at the lowest and highest resolutions but the gap is only 2% at 1680x1050 and 1920x1200. The performance growth relative to the Radeon HD 4870 1GB is 14 to 21% depending on the resolution. And the new card has no rivals when overclocked, beating both the GeForce GTX 285 and Radeon HD 4850 X2.
We use the game’s built-in benchmarking options which cannot measure the bottom frame rate. We enable DirectX 10.1 support for ATI’s solutions.
For an unknown reason the Radeon HD 4890 is just a little better than the Radeon HD 4870 1GB in this test. The gap is smaller than 4% at resolutions up to 1920x1200 and grows to 9% at 2560x1600. Overclocking adds 12-18% more, yet the GeForce GTX 285 and Radeon HD 4850 X2 are still superior at the lower resolutions. At high resolutions the frame rate is too low for smooth gameplay.
The game has a frame rate limiter fixed at 30fps.
The Radeon HD 4890 is ahead at both default and overclocked frequencies, outperforming the Radeon HD 4850 X2. Even the overclocked version has a rather low bottom speed at 1920x1200 and 2560x1600, though.
This resembles Tom Clancy’s H.A.W.X. because the Radeon HD 4890 is not much better than its predecessor, save for 2560x1600 where the frame rate is too low for comfortable play. The new card looks better when overclocked, ensuring a playable speed at 1680x1050, just like the GeForce GTX 285 does.
The non-overclocked Radeon HD 4890 is a little faster than the GeForce GTX 285 in terms of general score as well as in the individual groups of tests. When overclocked to 1000/1200 (4800) MHz, it even challenges the dual-processor Radeon HD 4850 X2: the gap is a mere 85 points in the SM3.0/HDR tests.
We minimize the CPU’s influence by using the Extreme profile (1920x1200, 4x FSAA and anisotropic filtering). We also publish the results of the individual tests across all display resolutions to provide a full picture.
The overclocked Radeon HD 4890 even beats the Radeon HD 4850 X2 in 3DMark Vantage, but the GeForce GTX 285 with its hardware and software PhysX support is better yet. The gap is only 300-350 points, though.
The new card enjoys the biggest advantage over the Radeon HD 4870 1GB at 1280x1024. When overclocked, it is faster than the Radeon HD 4850 X2 at 1280x1024 and equals the latter at the higher resolutions.
It’s different in the second test: the Radeon HD 4890 is ahead of the Radeon HD 4870 1GB in every display mode. When overclocked, it can only catch up with the Radeon HD 4850 X2 and GeForce GTX 285 at 1920x1200 and higher resolutions.
So, what can we say in conclusion to our first ATI Radeon HD 4890 test session? The “refresh” of the RV770 was definitely worth it. Reborn as RV790 the good old GPU got a second breath. Let’s take a closer look at the performance summary charts for each of the four tested resolutions.
In 1280x1024 the performance gain by Radeon HD 4890 compared to Radeon HD 4870 1GB varies from almost unnoticeable 0.5% in Far Cry 2 to pretty good 14% in Race Driver: GRID. The average gain is about 10%.
It may seem like not too much. But do not forget that the memory subsystem bandwidth has minimal effect on the results in this resolution and the chip frequency of the newcomer is only 100MHz higher: 850MHz vs. 750MHz by Radeon HD 4870 1GB.
Overclocking to 1GHz provides another 7-27% gain, which makes the new ATI solution even more attractive than GeForce GTX 285 in some cases. However, we can’t promise that any Radeon HD 4890 will overclock as well as the PowerColor HD4890 Plus sample we received. But even in its nominal mode Radeon HD 4890 defeated the competitor from a higher price range in six tests out of fifteen, which is really good for a sub-$240 graphics card.
In 1680x1050 resolution the average advantage demonstrated by Radeon HD 4890 over Radeon HD 4870 1GB grew a little higher reaching 11.5%. Overclocking produced another 14% on average, which was enough for a definite victory over GeForce GTX 285 in eight tests out of fifteen. But even without any overclocking our hero won in six of them!
As far as Radeon HD 4850 X2 is concerned, its future seems to be a little vague now that ATI has a GPU that can work at 850-1000MHz frequencies and maybe even higher than that. ATI’s graphics card partners gave this solution a chilly welcome not without reason. Only Sapphire decided to release the corresponding product. Looks like Radeon HD 4850 X2 and CrossFireX tandems with similar parameters may be pressed by Radeon HD 4890 OC in the corresponding price segments.
As the resolution increases, Radeon HD 4890 does even better. No wonder, actually, because the memory subsystem bandwidth starts to matter more for the performance in higher resolutions. And as we have already said, the memory subsystem bandwidth of the new ATI solution is way higher and equals 124.8GBps vs. 115.2GBps by Radeon HD 4870 1GB. The average advantage of the reference graphics card makes 12.5%, and in some games except Mass Effect and Race Driver: GRID doesn’t really exceed this level. Overclocking improves average performance by another 14%. As a result, this resolution becomes playable in such games as Prince of Persia and Mass Effect.
In the race again GeForce GTX 285 the regular Radeon HD 4890 wins in six tests out of fifteen, while the overclocked one wins in eleven and draws in one. The maximum lag in those tests it lost is only about 9%. This results into an average advantage of 13% in favor of new ATI solution.
The average performance gain over Radeon HD 4870 1GB in the highest resolution exceeds 13% and sometimes reaches 20%. Overclocking adds another 15% on average. The score is the same: 6:9 in Nvidia’s favor for the regular Radeon HD 4890 and 11:4 in favor of the overclocked ATI solution. This is a very good result for the card that wasn’t initially supposed to compete against the single-processor flagship product from the enemy camp.
So, the average performance increase demonstrated by the standard Radeon HD 4890 over Radeon HD 4870 1GB makes about 12% - not bad for only 100MHz higher GPU frequency and 75MHz higher memory frequency. In some cases it was even enough for the new solution to defeat an even more powerful rival – GeForce GTX 285. As for GeForce GTX 260 Core 216, it is no competitor to Radeon HD 4890 from several aspects, including the price. Therefore, very soon we are going to witness the battle between the Radeon HD 4890 and the new rival from the “green” camp – GeForce GTX 275. SO, stay tuned!
But what Radeon HD 4890 is really good at is overclocking. We have every reason to say so: even without any special tools and tricks we managed to raise the GPU frequency to 1GHz! This height has definitely been conquered easily, because as you remember, it used to be impossible to overclock a Radeon HD that far without any hardware modifications increasing the GPU voltage. Overclocked Radeon HD 4890 not only proved capable of competing successfully against GeForce GTX 285, but left the rival behind in majority of benchmarks. From this prospective, we think it made perfect sense for ATI to launch Radeon HD 4890 OC officially. Company partners will undoubtedly offer their own versions of this graphics adapter with the GPU speed beyond 900MHz. and if the price is reasonable enough it may have a serious effect on the marketing success of Nvidia solutions that managed to strengthen their positions quite well lately due to high-performance products based on 55nm G200 chips.
As for the specific product reviewed today, PowerColor HD4890 Plus, it is a typical representative of the RADEON HD 4890 OC family that is designed to work at higher GPU frequency. The manufacturer decided to play it safe and stick to ATI’s recommendations that is why the card only differs from the regular Radeon HD 4890 by 50MHz higher graphics chip frequency. It uses reference PCB layout and cooling system. Among the peculiarities of the PowerColor HD4890 Plus we could mention excellent overclocking potential. Other than that it is a good “work horse” for gaming fans who play in high resolutions but do not want to invest more than $300 into a new graphics card. As we have already said, we had a pre-production sample, so there was no accessories bundle with it. Besides that, there are no other drawbacks that we might want to mention here.