by Alexey Stepin , Yaroslav Lyssenko, Anton Shilov
08/08/2008 | 02:28 PM
The Radeon 4800 series enjoyed a successful debut, proving the worthiness of the developer’s new strategy. Thanks to the thought-through and thoroughly optimized architecture, the relatively simple and inexpensive Radeon HD 4850 and 4870 cards delivered high performance in games. The junior model was especially brilliant. Officially priced at only $199 it easily competed with the GeForce 9800 GTX that had been originally designed as a top-end product.
Although Nvidia offers the fastest single graphics card in the world, the monstrous GeForce GTX 280 is not much faster than the Radeon HD 4870 and not faster at all in some games. As you know, ATI had given up the development of monolithic GPUs for $449 and more expensive products. Instead, the developer relies on multi-GPU technologies to create competitive top-end solutions.
So, the Radeon HD 4800 series is going to be complemented with dual-processor Radeon HD 4870 X2 and 4850 X2. Drawing upon the combined power of two RV770 cores, these new solutions are expected to be as fast as to leave no chance to the GeForce GTX 280. But considering Nvidia’s recent price cuts, the Radeon HD 4870 X2 will be more expensive since its price will in fact equal the cost of two Radeon HD 4870 cards minus the two PCBs and plus one expensive dual-processor PCB and a PCI Express switch. All in all, the Radeon HD 4870 X2 will cost more than $500 whereas the official price of the GeForce GTX 280 is currently set at $499.
But the point of the multi-GPU strategy is in quickly satisfying customers’ needs by means of good mainstream graphics cores. A Radeon HD 4850 X2 would be a logical answer to the GeForce GTX 280. This card is going to come out soon, being on ATI’s official product schedule. But even without it, we’ve got the highly successful Radeon HD 4850. Two such cards would cost you a mere $400 while CrossFire technology is currently supported not only by AMD’s but also by Intel’s chipsets. You just need two PCI Express x16 slots on your mainboard. Thus, a Radeon HD 4850 CrossFire configuration seems to be a nice alternative to a GeForce GTX 280, especially if your system supports CrossFire technology and has an empty PCI Express x16 slot. You can also increase the performance of your graphics subsystem in two steps and at a relatively low cost. The question is how efficient such a tandem would be under real-life conditions and if multi-GPU platforms have finally escaped the status of marginal solutions for enthusiasts only.
The answer is important not only for gamers searching for an alternative to the GeForce GTX 280 but also for ATI. The company’s future depends on how efficient CrossFire technology is. So, in this review we will check out the performance of a Radeon HD 4850 CrossFire configuration in 17 tests (15 games and two synthetic benchmarks). We’ll build our CrossFire config out of two Sapphire HD 4850 512MB GDDR3 cards that will be described in the next section.
The package design has been revised since previous products from Sapphire. The color scheme has become more restrained and elegant. Big-headed aliens, reminding one of sci-fi B-movies, have vanished from the face side of the box to give way to a redhead relation of Ruby, ATI’s official talisman, and the boastful caption “Prepare to Dominate.” So, the box with the Sapphire HD 4850 512MB GDDR3 is quite appealing but not gaudy:
There are a couple of inaccuracies on the face side of the box. The card is declared to support 5:1 audio but the RV770 can actually do more. It supports eight-channel audio, in both ordinary and HD formats. And second, the previous generation of ATI’s GPUs already supported Shader Model 4.1. Of course, it is supported by the RV770, too.
The stickers inform you of the amount of graphics memory (there is a version of this card with 1 gigabyte of GDDR3 on board) and various bonuses included into the box. The colorful cover envelopes the box proper. Its contents are protected with sheets of foam rubber, and the graphics card is additionally wrapped into a blister pack. The Sapphire HD 4850 512MB GDDR3 comes with the following accessories:
There is no Molex → 6-pin PCI Express adapter in the box, but that’s not a big problem since most modern PSUs offer at least one 6-pin power plug for your graphics card. The accessories are generous overall, especially for a mainstream product. We wish products from other brands came with as much additional stuff.
We are especially glad to see a full-featured video player supporting HD formats. Such software is but rarely included with graphics cards although playing HD video is the second most important use of a modern graphics card after running games. The DVD Suite disc contains media content processing software you may find useful. The AMD Ruby ROM disc is a kind of promotional as it contains demos of games and ATI’s exclusive screensaver and Desktop wallpapers. And finally, there is a disc with a full version of Futuremark 3DMark06. This benchmark should be familiar to every PC enthusiast.
The 2GB USB flash drive with a Sapphire logo is a nice accessory, too. It may have little to do with 3D graphics but, unlike a web-camera or gamepad, will be surely found useful by everyone. The sticker on the box informs you that it is a limited offer and the USB flash drive may be excluded from the contents of the Sapphire HD 4850 512MB GDDR3 box.
So, we can find no fault with the packaging or accessories of the described product. Both are high class. We can only hope that other vendors will provide as much accessories with their products as Sapphire does. Even though the accessories do not affect the graphics card’s functioning, it is nice to have them. The brand earns a good reputation by showing such a generous attitude towards the user.
The Sapphire HD 4850 512MB GDDR3 being a precise copy of the reference card, we won’t discuss its electrical, acoustic and thermal characteristics at length because we did all of that in our review of ATI’s new graphics architecture.
For our performance tests of ATI Radeon HD 4850 CrossFire and its comparison against Nvidia GeForce GTX 280 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, to ensure maximum image quality, 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 CrossFire we have also included the following graphics accelerators to participate in our test session:
Since we are talking about high-performance solutions from the high-end segment, it is extremely interesting to check out their performance i resolutions beyond 1920x1200. That is why we also added 2560x1600 and 2048x1536 (the latter is valid only for those games that do not support 16:10 screen format). 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 Radeon HD 4870 CrossFire and GeForce GTX 280 both handle this test easily. They ensure high speeds even at a resolution of 2048x1536 pixels. The Radeon tandem is somewhat faster in the hardest display mode but the difference is less than 5%.
Talking about the usability factor, the Radeon HD 4850 CrossFire subsystem requires an appropriate mainboard but the cards are shorter than a GeForce GTX 280, occupy two slots like the latter card, and need two 6-pin power connectors whereas Nvidia’s card won’t work without your attaching an 8-pin PCI Express 2.0 connector to it. Nvidia’s card is more economical, though. Its peak power consumption is 178 watts as opposed to 200 watts of two Radeon HD 4850 cards working in CrossFire mode.
BioShock doesn’t support FSAA when running in Windows Vista’s DirectX 10 environment. We benchmark graphics cards without FSAA in this game
Alas, the Radeon HD 4850 CrossFire configuration doesn’t show stable results in this test. Its performance doesn’t go near the predicted level. Moreover, CrossFire mode is downright incorrect at 1920x1200 where the average frame rate of the tandem is lower than the speed of the single Radeon HD 4850.
The 2560x1600 results are disappointing for the CrossFire system due to the low bottom speed. Nvidia’s solution, on the other hand, delivers comfortable performance in terms of both average and minimum speed. The single Radeon HD 4870 is also good here and seems to be the most valuable investment for this game.
We didn’t benchmark the cards at 2560x1600 because the game doesn’t support resolutions above 1920x1200 pixels.
The Radeon HD 4850 CrossFire subsystem wins in every tested mode. It is over 50% faster than the GeForce GTX 280 but its bottom speed is no higher than 20fps. It means the game may be jerky and sluggish in complex action-heavy scenes. Still, the average frame rate of the Radeon HD 4850 CrossFire is high enough for you to try display resolutions higher than 1280x1024 in Call of Juarez.
The Radeon HD 4850 CrossFire isn’t good here. Although its performance doesn’t plummet down as that of the Radeon HD 3870 X2, it is only as fast as the single Radeon HD 4850. The CrossFire subsystem can almost match the GeForce GTX 280 at 1920x1200 yet its full potential remains untapped.
The GeForce GTX 280 wins at 2560x1600. The amount of graphics memory is not the cause for that considering the results of the GeForce 9800 GX2 which has a total of only 512 megabytes. Therefore we cannot explain the performance of the Radeon HD 4870 which should be far faster than the Radeon HD 4850 like at the lower resolutions, but the difference between them becomes negligible at 2560x1600. Well, the speed is high enough for you to play the game even at 2560x1600.
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 strike a balance between image quality and speed.
ATI’s tandem equals the GeForce GTX 280 at 1600x1200 and surpasses it at 1920x1200 but has a lower bottom speed in comparison with the single card. Nvidia’s solution is on the winning side but its performance is barely acceptable at 1280x1024 as the bottom speed is lower than 25fps.
The game obviously needs more than 512 megabytes of memory to run at 2560x1600 pixels. Thus, it runs on the GeForce GTX 200 series only.
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.
CrossFire technology shows low efficiency. The Radeon HD 4850 CrossFire configuration has the same performance at 2560x1600 as the single Radeon HD 4870. This is about 16% slower than the speed of the GeForce GTX 260 and equal to the result of the GeForce GTX 260. From a practical point of view, the average frame rate is high enough for playing the game at the highest resolution together with 4x MSAA.
CrossFire technology provides a performance gain of 31-32% at 1920x1200. Not much, but enough for the Radeon HD 4850 subsystem to match the GeForce GTX 280 in terms of average performance. The ordinary single Radeon HD 4870 delivers a similar result, though.
It’s somewhat different at 2560x1600. The Radeon HD 4870 loses its ground, being about 25% slower than the Radeon HD 4850 CrossFire while the latter solution remains on the same level with the GeForce GTX 280, showing identical potential at a lower price.
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.
ATI’s multi-GPU solutions have always been fast in this game. The Radeon HD 4850 CrossFire is not an exception. This subsystem is roughly similar to or somewhat slower than the GeForce GTX 280 at resolutions up to 1920x1200 inclusive. The gap grows to 8% at 2560x1600 but the CrossFire subsystem is fast enough for comfortable play.
SLI technology doesn’t have good support in this game. The GeForce 9800 GX2, potentially faster than the GeForce GTX 280, has unsatisfactory results. The developer has obviously abandoned the previous-generation solution in favor of the new series just as he had done with the GeForce 7950 GX2.
Alas, CrossFire technology doesn’t work in this game. There is no performance growth relative to the single card. ATI’s solutions are superior, though. The Radeon HD 4870 outperforms the GeForce GTX 280 even at 2560x1600 notwithstanding the smaller amount of memory and the narrower memory bus.
Nvidia’s new-generation solutions and the dual-chip monster of the previous generation are unrivalled although ATI’s cards ensure comfortable play at resolutions up to 1920x1200. It is at a resolution of 2560x1600 that we can see why the GeForce GTX 200 is endowed with such advanced hardware resources. The minimum speed of the Radeon HD 4870 is not far lower than that of the GeForce GTX 260, though. CrossFire technology doesn’t work in this game and the CrossFire tandem has almost the same results as the single such card.
This game is sensitive to the amount of graphics memory at the highest level of detail. This shows up in the bottom speed of the graphics cards. However, the Radeon HD 4850 CrossFire tandem has an acceptable speed at resolutions below 2560x1600 even though it is but 35-37% faster than the single such card.
512 megabytes of memory is not enough for 2560x1600. The GeForce GTX 280 remains the only graphics card to maintain a comfortable speed at that resolution. The GeForce GTX 260 has a surprisingly low bottom speed despite its 896 megabytes of onboard memory. It means the problem of inefficient memory management that used to plague the GeForce 8/9 series persists in the GeForce GTX 200 series, too.
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 CrossFire enjoys a lead over the GeForce GTX 280 starting with a resolution of 1600x1200. The gap amounts to 15% at 2560x1600. In open scenes the gap is smaller, amounting to 11-12% at 2560x1600. Contrary to the ATI solution, the GeForce 9800 GX2, a dual-chip solution too, does best at low resolutions and matches the performance of the GeForce GTX 260 at high resolutions.
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 Radeon HD 4850 CrossFire doesn’t match the single Radeon HD 4870, unfortunately. Despite a notable advantage in average frame rate, its bottom speed is below comfortable even at 1280x1024.
The gap from the GeForce GTX 280 is a mere 4% at 2560x1600 but the minimum speed of each solution is too low for you to enjoy smooth gameplay.
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.
There is no difference between the Radeon HD 4850 CrossFire and the GeForce GTX 280 even at a resolution of 2560x1600 where each graphics subsystem hits the frame rate limit. The single Radeon HD 4870 and GeForce GTX 260 are no worse, though.
It is only at 1920x1200 that the Radeon HD 4850 CrossFire platform is competitive to the GeForce GTX 280. The single Radeon HD 4870 delivers somewhat higher bottom and average frame rates under the same conditions.
Nvidia’s flagship product is notably faster although has a lower bottom speed than ATI’s dual-GPU subsystem. Unfortunately, every tested graphics subsystem has a low button speed in this test. The best result comes from the Radeon HD 3870 X2, yet it is lower than 25fps. We hope for better results from the upcoming Radeon HD 4870 X2 which is superior to its predecessor in every parameter.
The Radeon HD 4850 CrossFire tandem sets a new record but doesn’t reach 14,000 points. It scores only 223 points more than the Radeon HD 3870 X2.
The Radeon HD 4850 tandem is inferior to the Radeon HD 3870 X2 in the SM2.0 tests, obviously due to the lower frequency of the graphics cores, but leaves its opponents far behind in the SM3.0/HDR tests, almost notching 8,000 points.
Contrary to what we have come to expect, the Radeon HD 4850 CrossFire successfully competes with the GeForce GTX 280 in the first SM2.0 test that has always been Nvidia’s playground. This is achieved thanks to the superb scalability of CrossFire technology that amounts to nearly 80% on switching from one to two GPUs.
CrossFire technology is only 65% efficient in the second test, but that’s enough to beat the GeForce GTX 280 even though the latter features improved geometry processing. Nvidia’s dual-chip GeForce 9800 GX2 is as fast as ATI’s solution here, though.
ATI’s solutions have always been strong in the SM3.0/HDR tests and the GeForce GTX 280 is routed by the Radeon HD 4850 CrossFire now. The gap is 31% in the first test and 17% in the second test. The single Radeon HD 4870 is competitive to Nvidia’s flagship card in both cases.
We minimize the CPU’s influence by using the Extreme profile (1920x1200, 4x FSAA and anisotropic filtering).
The Radeon HD 4850 CrossFire subsystem stopped just short of the GeForce GTX 280’s score. This is the indication of high efficiency of CrossFire technology and of the imminent win of the Radeon HD 4870 X2.
The GeForce GTX 280 is in the lead in the first test. It is quite surprising since the test abounds in complex computations that are performed best on ATI’s solutions. The Radeon HD 4850 CrossFire wins the high-texture-load second test, which is a kind of a surprise, too. Well, the two cards in the CrossFire configuration have a total of 80 texture processors which seem to be more effective than Nvidia’s.
With the test results of the Radeon HD 4850 CrossFire on our hands, we can speak quite definitely about its potential and competitiveness, particularly against Nvidia’s GeForce GTX 280. The results are not favorable for ATI overall. Although the CrossFire solution is indeed unrivalled in a number of tests, it could not outperform the GeForce GTX 280 in others due to the drawbacks typical of all multi-GPU solutions.
The summary diagrams make it clear.
The Radeon HD 4850 CrossFire subsystem beats the GeForce GTX 280 in two cases at a resolution of 1280x1024: Call of Juarez (by 56%) and Lost Planet (about 18%). A small advantage (of about 9%) can be observed in both scenes of TES IV: Oblivion. In Battlefield 2142, HL2: Episode 2 and S.T.A.L.K.E.R. the ATI solution is within 5% from the leading GeForce GTX 280. In the rest of the tests the CrossFire subsystem is far behind its opponent, by 30% and more, mainly due to incorrect operation of CrossFire technology. In fact, only one out of the two GPUs was working in these games. Thus, the overall score is 8 to 4 in favor of Nvidia, with four draws, and two wins of ATI in 3DMark which have no practical value. Not very optimistic results.
Things are brighter for ATI if the Radeon HD 4850 CrossFire is compared with the GeForce GTX 260: five wins, four draws and seven losses in the gaming tests, plus two wins in 3DMark. However, this card from Nvidia belongs to a lower price category costing $299 (two Radeon HD 4850 cost $400).
The overall picture is the same at a resolution of 1600x1200 except that the Radeon HD 4850 CrossFire increases its lead to 70% in Call of Juarez proving the big potential of two RV770 chips working together. In S.T.A.L.K.E.R. and TES IV: Oblivion the GeForce GTX 280 is, on the contrary, closer to the ATI solution, but the latter shrinks the gap in Crysis from 14% to 4%. The overall standings thus remain the same.
In comparison with the GeForce GTX 260, ATI’s solution has six wins and four draws and thus looks more appealing, especially as CrossFire support will be eventually added into more games. The price factor should not be forgotten, though. Even the single-PCB Radeon HD 4850 X2 is unlikely to fit into the $299 category the Radeon HD 4870 resides in.
The display resolution grows higher and the Radeon HD 4850 CrossFire wins five tests from the GeForce GTX 280 but its advantage in TES IV: Oblivion shrinks to 5%. In five more tests the difference is small or zero, so if ATI’s people work hard on correcting the problems of CrossFire technology, which they should be busy with right now, the GeForce GTX 280 will have a dangerous rival. ATI’s advantage will grow if the upcoming Radeon HD 4850 X2 is equipped with more graphics memory.
Compared with the GeForce GTX 260, the Radeon HD 4850 CrossFire wins seven out of the 16 tests, has a small advantage over the Nvidia card in three more tests, and lost only in BioShock and Tomb Raider: Legend.
It is the extremely high resolutions of 2048x1536 and 2560x1600 pixels that are the most interesting but ATI has nothing exciting to offer here at the moment. In many tests the Radeon HD 4850 CrossFire tandem lacks graphics memory. Although the two cards have a total of 1 gigabyte of local memory, applications can only use half that amount (which is the case for every modern homogeneous multi-GPU solution if the cards have the same amount of memory). As a result, ATI’s subsystem wins only in TES IV: Oblivion and equals its opponent in Battlefield 2142, HL2: Episode 2 and CoH: Opposing Fronts. On the other hand, the Radeon HD 4850 CrossFire delivers a playable frame rate in every of these games, except for CoH: Opposing Fronts, and also in C _©C: Kane’s Wrath So we are looking forward to benchmark the Radeon HD 4850 X2 that may be faster due to a larger amount of graphics memory and improved drivers.
The GeForce GTX 260 is not meant for such high display resolution, but the comparison is interesting anyway. Here, each solution wins five tests. They equal each other in five more tests. So, this is a draw overall.
Generally speaking, the Radeon HD 4850 CrossFire configuration has big potential. But this potential is not revealed fully due to poor driver support for CrossFire technology, which is a common problem of all multi-GPU solutions, and to the insufficient amount of local memory. 512 megabytes of graphics memory is not enough for a number of today’s games at resolutions higher than 1600x1200/1680x1050. Still, purchasing a couple of Radeon HD 4850 cards to build a CrossFire subsystem out of them is an interesting option for a user who wants to have high performance in games.
ATI has focused on multi-GPU solutions and is now interested in promoting such technologies. So the mentioned configuration may soon become a threat to the GeForce GTX 280 especially considering the higher price of the latter. But if you don’t have yet a Radeon HD 4850 and don’t plan to modernize your graphics subsystem in two steps, you may want to wait for the Radeon HD 4850 X2. Besides being easier to handle, this graphics card will be free from the second drawback of the Radeon HD 4850 CrossFire, i.e. the low amount of graphics memory available to 3D applications.
As for the specific product, the Sapphire HD 4850 512MB GDDR3 graphics card pleased us with its pretty packaging and rich accessories that include everything necessary to use the card as well as a few bonuses, particularly a software player of Blu-ray and HD DVD formats and a 2GB USB flash drive.
We here at X-bit labs decided to award Sapphire Radeon HD 4850 512MB GDDR3 with our prestigious Editor’s Choice title for the best accessories bundle among comparable graphics accelerators: