by Alexey Stepin , Yaroslav Lyssenko
01/12/2009 | 11:10 AM
As you know from our news reports and reviews, AMD’s graphics department successfully turned the tables on its opponent by introducing a new mainstream-class graphics core. The RV770 GPU not only beat its rivals but even challenged Nvidia’s solutions from higher price categories.
A squadron is represented by its flagship in the first place. Although luxurious graphics cards priced at $500 and higher account for but a small share of sales, they symbolize the technological achievement of the developer and his ability to stay at the edge of progress. To produce such a flagship, ATI combined two RV770 cores on one PCB using its time-tested CrossFire technology. The company had introduced such solutions before: the release of the Radeon HD 3870 X2 can now be viewed as a simulation of the decisive battle. Its technological successor Radeon HD 4870 X2 left no chance to the GeForce GTX 280, proving that Nvidia’s strategy of developing the fastest monolithic GPU had been miscalculated.
ATI’s triumph in the premier league of graphics cards did not come easy, though. The Radeon HD 4870 X2 cost much more than the GeForce GTX 280 and had a terrifying level of power consumption, over 200 watts! On the other hand, the single-core Radeon HD 4870, even equipped with 1 gigabyte of fast GDDR5 memory, could not match Nvidia’s flagship in terms of gaming performance, although was far more economical and cheaper. A couple of Radeon HD 4850 or even 4830 cards might make a competitive solution but discrete multi-GPU configurations, i.e. those that consist of multiple graphics cards and occupy several PCI Express slots, had proven to be niche solutions. They can only be interesting for people who already own one such card and seek for a cheap way to increase the performance of their gaming platform. The main reason for the low popularity of such configurations is that they are not easy to deal with. They take too much space in the system case and are incompatible with some mainboards.
ATI unveiled the opponent to the GeForce GTX 280 from the beginning: the cheaper and less advanced Radeon HD 4850 X2 was announced along with the Radeon HD 4870 X2. It uses GDDR3 memory instead of the latter’s super-fast and expensive GDDR5.
Unfortunately, the new card didn’t make its market debut quickly. Announced on August 12, 2008, together with the 4870 X2, it only came to market in November. Graphics card makers delayed with launching it into mass production (see this story for details). This delay may have been due to the apprehensions that the new card might have low performance if only one of its GPUs was active. This can happen to a homogeneous multi-GPU system if it lacks support on the side of the driver or gaming application. Anyway, the Radeon HD 4850 X2 is being manufactured now. And since the recommended price of the new card is $350-399, Nvidia has got a reason to worry because the GeForce GTX 280 seems to have exhausted every means for reducing the manufacturing cost.
In this review we will compare the top-performance solutions from ATI and Nvidia belonging to the same price category to give the final answer to the question whose development strategy is the optimal and winning one. The two camps are represented by a dual-core Sapphire HD 4850 X2 2G/1G GDDR3 and a Leadtek WinFast GTX 280. Sapphire’s card has lower GPU frequencies and GDDR3 memory but will the Leadtek make use of these weaknesses to gain advantage? The fight is going to be the more interesting because our testbed has been modified to meet today’s requirements.
First, let’s compare the parameters of today’s fighters. The specifications and capabilities of the GeForce GTX 280 should be already well known to our readers, so we will begin with the newcomer. As we noted above, the ATI Radeon HD 4850 X2 is a 4850 CrossFire tandem designed on a single PCB just as the Radeon HD 4870 X2 represents the single-PCB version of a Radeon HD 4870 CrossFire configuration. This is reflected in its specs:
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Indeed, these solutions only differ in terms of memory type and GPU clock rates, being identical in every other respect.
Comparing it with the GeForce GTX 280, the Radeon HD 4850 X2 has a tremendous advantage in computing resources, judging by the amount of ALUs. We should not forget about the superscalar design of the RV770’s shader processors, however: each of these 320 processors incorporates five ALUs, but not all of these five are utilized at every given moment. Moreover, Nvidia’s shader processors are clocked at a frequency of 1.3GHz as opposed to 625MHz of ATI’s solution. The DirectX 10.1 support is not a serious advantage, either. There are but few DirectX 10.1 applications available today, S.T.A.L.K.E.R.: Clear Sky being the only such game in our test programme.
The two cards seem to be equal in terms of texture processors, but Nvidia’s 80 texture processors often behave as only 40 processors effectively in real-life applications whereas the total amount of TMUs of the Radeon HD 4850 X2 is 80 if both GPUs are fully utilized by the application. Neither card seems to be superior in terms of rasterization processors whose efficiency depends on their internal design. Anyway, raster back-ends are not a decisive factor in modern games. More importantly, the Radeon HD 4850 X2, unlike its elder brother, has no advantage in terms of memory bandwidth. Its theoretical memory bandwidth is only 128GBps. The GeForce GTX 280 is somewhat better in this respect.
Thus, the current flagship of the GeForce series has good chances in the upcoming fight. Let’s now take a closer look at each fighter before they come to blows.
Sapphire’s card comes in a small box that is about the same length as the graphics card itself. You can easily put this box into a plastic bag, so the lack of a carry handle won’t be a nuisance. Designed in blue tones, with a metallic effect and raised labels, the box is attractive even though the picture of a superficially dressed girl armed with two katana and accompanied with the slogan Prepare to Dominate looks trivial.
The marketing thought does dominate over the reality here as the box shows a “2GB GDDR3” sticker. Well, this is no lie, formally speaking, because the card does carry two sets of memory chips, 1024MB each. But being a homogeneous multi-GPU solution, the Sapphire HD 4850 X2 can only offer 1GB of graphics memory to user applications (memory data are duplicated for the two GPUs). The “4x Display Support” caption means that this card can work with four monitors simultaneously. We will discuss this capability shortly.
The packaging doesn’t provide any special protection for the card. There is a plain cardboard box insider the colorful wrapper. The Sapphire HD 4850 X2 is packed into a thick blister wrap and lies at the top part of the box. The bottom part is occupied by another box containing the card’s accessories. The list is quite extensive:
The accessories are good for this price category but we don’t like the outdated version of PowerDVD which doesn’t provide full-featured support for high-definition video, although supports H.264 decoding. The DVD Suite contains older versions of applications, too, but it may be found useful by users who don’t work with HD video. The included version of Futuremark 3DMark Vantage is a full-featured one because the only difference of the Advanced Edition and Professional Edition licenses is that the former does not permit a commercial usage of the software. An ordinary user can hardly use 3DMark Vantage for commercial purposes anyway. The Ruby ROM disc is rather a piece of advertising. Besides AMD’s exclusive wallpapers and screensavers, it contains demo versions of Call of Juarez and Stranglehold, a full version of the MMORPG Dungeon Runners, a trial version of the virtual globe Earthsim, and the GameShadow tool. The latter can help you organize your installed games into a single collection with the options of updating them, getting info about new games, etc.
We don’t have any gripes about the adapters and cables. The kit contains everything necessary to use the card even if your PSU lacks any PCI Express connectors. Well, we don’t think there are PSUs capable of delivering the required current over the +12V rail but not having at least one graphics card connector. So, the accessories to the Sapphire HD 4850 X2 2G/1G GDDR3 are good overall. They would be even perfect if the manufacturer included a video player with HD content support and some popular game.
The representative of the green camp comes in a rather small box, too. At least, it is small in comparison with some products from ASUS that are as large as a briefcase. The box is designed in white-and-orange colors like every other top-end product from Leadtek since GeForce 9800 GT.
The war robot on the face side of the box is just as trivial as the picture on Sapphire’s box, but it does attract the eye of the potential customer. The box offers as much information as Sapphire’s and correctly states the amount of memory available to 3D applications. The WinFast GTX 280 is a single-core solution and has 1024 megabytes of onboard memory. The contents of the box are fixed amidst pieces of soft foam-rubber that protect against any accidents during storage and transportation.
Besides the card proper, the box contains the following accessories:
The accessories are far from gorgeous considering the product category the Leadtek WinFast GTX 280 belongs to. There are no such necessities as a DVI-I → HDMI adapter or a cable for connecting the sound card’s S/PDIF to the appropriate input on the graphics card. It’s strange that the manufacturer has disregarded HDMI in such a manner. This is one of the most important interfaces today, after all. It doesn’t matter then that the box does not contain software for playing high-definition video. The Sapphire HD 4850 X2 kit doesn’t include such software, either. The outdated version of PowerDVD cannot be counted in.
The adapter from two 6-pin PCIe into one 8-pin PCIe connector may turn to be unhandy. It takes two 6-pin connectors, but many PSUs have only two or even one such connector. You can make up for this by means of adapters from 4-pin Molex connectors, but the single included adapter may be not enough. Moreover, there is no good in assembling a garland of adapters because it would contain a lot of contacts creating additional resistance and reducing the overall reliability of the connection. Therefore the configuration of adapters offered by Sapphire looks better as it ensures problem-free connection of the card even if your PSU does not offer native PCI Express connectors at all.
Leadtek’s kit has one special advantage, though. It includes a copy of Neverwinter Nights 2. The game is not particularly new, but remains an etalon of the role-playing genre. Of course, it’s better to have a full game than beta versions such as offered by Sapphire with their card. Coupled with this game, the accessories to the Leadtek WinFast GTX 280 can be considered as good. Sapphire’s accessories were good, too. The two products are so far equals.
Like the Radeon HD 4870 X2, the Sapphire HD 4850 X2 represents a highly sophisticated design. Having the same dimensions as the GeForce GTX 280, it has to carry two GPUs with two sets of memory chips, a PCI Express switch chip, and an appropriate power circuit. However, ATI Technologies’ closest partner was not taken aback and developed a unique PCB for this product. It has nothing to do with ATI’s reference design. The card is an imposing view with the cooler’s casing installed:
The two fans seem to promise a low level of noise, but, running a little ahead, we should confess that the card is very noisy due to its weak GPU heatsinks. Besides, the four DVI-I connectors left no space on the card’s mounting bracket for vent holes that could be used to exhaust the hot air out of the system case.
As a result, the hot air from the card remains within the system. The RV770 core being of a hot temper, you have to take care about proper ventilation of your system case. The cooler’s casing can be removed easily. You can unfasten four screws near each fan and have a look at this:
So, each GPU is cooled with an individual heatsink/fan pair. The heatsinks are made from aluminum but have a copper sole in the place of contact with the GPU die. They are rather small and light, so each heatsink is fastened with four spring-loaded screws only, without back-plates. The common dark-gray thermal grease is used as a thermal interface here.
You may wonder why the manufacturer didn’t use a more efficient single heatsink that would cool both the GPUs simultaneously. Well, it just wouldn’t be easy to ensure proper contact between such a heatsink and the components. Moreover, the row of electrolytic capacitors located between the heatsinks above the PCI Express switch would get in the way then. The switch itself is cooled with an individual needle-shaped heatsink fastened with thermal glue. We didn’t dare to tear it off, but it must conceal a PLX Technology PEX8647 chip, the same chip as on the Radeon HD 4870 X2.
Interestingly, all the memory chips of the Sapphire HD 4850 X2 are placed on the face side of the PCB whereas the reference Radeon HD 4870 X2 has half of the chips on the reverse side of the PCB. The chips are cooled with simple L-shaped aluminum plates fastened with three spring-loaded plastic clips. The thick elastic pads ensure proper thermal contact. This should be enough to cool GDDR3 memory considering the airflow from the fans.
The Sapphire HD 4850 X2 carries a total of 16 memory chips (QimondaHYB18H1G321AF-10) with a capacity of 1Gb (32Mb x 32), voltage of 1.8V and rated frequency of 1000 (2000) MHz. 16 such chips make up two memory banks with a capacity of 1024MB and a 256-bit memory bus: one bank for each GPU. The two banks store two copies of the same data due to the specifics of CrossFire technology, so the total amount of local memory available to 3D applications is 1024 megabytes. The memory is clocked at 993 (1986) MHz, which corresponds to the official Radeon HD 4850 X2 specs. There is little room for overclocking since the memory chips have an access time of 1 nanosecond.
The GPUs were both manufactured on the 37th week of 2008, i.e. in early September. Their memory controllers are reprogrammed for the use of GDDR3 instead of GDDR5 but you can’t distinguish the two versions of the RV770 chip by its marking. The marking offers no information for the uninitiated, save for the manufacturing date. The Sapphire HD 4850 X2 processors are clocked at 625MHz, which corresponds to the official specs, too. Considering the small heatsinks and the fact that the Radeon HD 4850 has a peak power draw of 110 watts, we can’t expect the Sapphire HD 4850 X2 to be quiet or economical.
The power circuit has nothing to do with that of the Radeon HD 4870 X2. Highly sophisticated, it is mostly located on the reverse side of the PCB, with only a few components nestled between the two GPUs. There is a two-phase voltage regulator based on a uPI uP6201BQ controller with three Infineon 042N03LS power transformers in each phase. The purpose of this regulator is rather unclear. It may be responsible for the memory chips and the PCI Express switch but can also take part in regulating the GPU voltage. The larger portion of the power circuit is hidden under two aluminum heatsinks: it is a seven-phase regulator with two external power connectors, one of which is of the 8-pin 150W variety, just like on the Radeon HD 4870 X2. The use of this connector is justifiable as the card is going to have a peak consumption of 220-230W. The connectors are placed near each other, which makes it easier to connect power cables to them than to the power plugs of the Radeon HD 4870 X2. Anyway, the connection process would be even handier if the connectors were turned by 90 degrees as on the GeForce GTX 280.
As for the four DVI connectors, this graphics card is indeed capable of supporting four monitors at any resolutions up to 2560x1600. As opposed to Nvidia’s SLI, ATI’s CrossFireX technology does not impose any limit on the number of monitors: this number depends only on many GPUs and display controllers the card has. The reference designs of the X2 series cards developed by ATI provide for the installation of only two DVI ports, and only one of them is used usually. Sometimes a large panel is connected to the second port via a DVI → HDMI adapter. Thus, it is unclear what user category is targeted by Sapphire with this solution. The Sapphire HD 4850 X2 is not a professional graphics card and won’t be used for appropriate applications. The support for four monitors simultaneously might be considered as an advantage if its implementation did not worsen the cooling system: the card lacks vent slits in its mounting bracket and cannot exhaust the hot air out.
Besides the DVI ports, the card is equipped with a standard 7-pin mini-DIN connector that can output video in Composite, S-Video and YPbPr formats. It also has one CrossFire connector for building a four-GPU subsystem out of two Sapphire HD 4850 X2 cards. But this would be a dangerous experiment considering that the cards do not exhaust the hot air out of the system case. It is no good having two heaters with a combined dissipated power of 440-460W inside your computer.
Thus, the Sapphire HD 4850 X2 seems to have a good design, save for two points. We don’t grasp the purpose of the developer’s idea of installing four DVI ports, and the cooling system is obviously ineffective for such an advanced card.
Like every version of GeForce GTX 280 we have tested in our labs, Leadtek’s is a precise copy of Nvidia’s reference sample. The sticker on the cooler’s casing is the only difference:
The PCB is as long as the Radeon HD 4870 X2 and HD 4850 X2, i.e. 27 centimeters, and the GeForce GTX 280 is not far simpler than the latter cards. Although it has only one GPU on board, it uses a 512-bit memory bus. So, it is very unlikely that some graphics card maker will come up with a nonstandard PCB for GeForce GTX 280.
A seven-phase GPU voltage regulator based on a Volterra VT1165MF controller resides in the right part of the PCB under the cooler’s casing. It has two connectors for external power supply, one of which is of the 8-pin variety. It is impossible to connect the PSU’s 6-pin connector to the latter: the card won’t start up, reporting a power problem by means of a red LED on the mounting bracket. The memory voltage regulator is based on a Richtek RT9259A controller that is powered by the PCI Express x16 slot.
Like the Sapphire HD 4850 X2, the Leadtek WinFast GTX 280 is equipped with 16 memory chips. These are Hynix H5RS5223CFR-N2C chips with a capacity of 512Mb (16Mb x 32), voltage of 2.05V, and rated clock rate of 1200 (2400) MHz. They make up a 1024MB memory bank accessed across a 512-bit memory bus. The memory is clocked at a frequency of 1100 (2200) MHz, providing a bandwidth of 140.8GBps, which is higher than the total bandwidth of the Sapphire HD 4850 X2 (128GBps). Half of the chips are located on the reverse side of the PCB and cooled with a metallic plate that is part of the cooling system. Fiber pads soaked in white thermal grease, typical of all solutions from Nvidia, are used as a thermal interface.
As opposed to the RV770, the die of the G200 processor has a heat-spreading cap protecting it from damage. The Leadtek WinFast GTX 280 comes with a revision A2 core marked as G200-300-A2. The second number seems to indicate a chip series according to the frequency and/or number of operating functional subunits. The core works in its full configuration with 240 unified shader processors, 80 texture-mapping units, and 32 raster back-ends. The card has the same GPU frequencies as the reference sample: 1296MHz for the shader domain and 602MHz for the main domain (including the raster back-ends).
The G200 is manufactured on 65nm tech process. Even without the display controllers it is as large as 576 sq. mm, incorporating 1.4 billion transistors. Therefore the display controllers are implemented as an individual NVIO2-A2 chip located near the DVI connectors. The graphics card is equipped with two dual-link DVI-I ports supporting resolutions up to 2560x1600, one universal analog video output, two SLI connectors (to combine up to three cards in a single multi-GPU subsystem), and an internal S/PDIF header. The latter is necessary to translate digital sound from your sound card into HDMI because the G200 does not incorporate an audio core.
The Leadtek WinFast GTX 280 uses the time-tested cooler that traces its origin back to the cooler of the GeForce 8800 GTX. Leadtek’s card differs from other versions of GeForce GTX 280 with the stickers: a picture of a robot on the cooler and a Leadtek logo on the fan.
The cooling system is based on a large heatsink consisting of thin aluminum plates and connected with heat pipes to the copper sole that contacts with the GPU cap. The metallic casing is part of the heat dissipation system, too. The aluminum base of the cooler has protrusions with thermal pads against those elements that require additional cooling such as power transistors or the NVIO chip. The airflow is created by a blower located at the back of the card. It blows through the heatsink and the hot air is exhausted out of the system case through the slits in the card’s mounting bracket. The cooler boasts high efficiency. The fan works at a reduced speed most of the time, ensuring comfortable noise level.
This cooling system seems to be better than Sapphire’s but its job is simpler, too. It has to cool one GPU only and the peak power consumption of the GPU is lower than the combined consumption of two RV770 chips even when the latter are clocked at reduced frequencies. We’ll check this out in the next section, though.
It is interesting to see how much power the Radeon HD 4850 X2 really needs. Although our version of the card has a nonstandard design of the power circuit, we measured its power consumption on the following testbed:
The 3D load was created by means of the first SM3.0/HDR test from 3DMark06 running in a loop at 1600x1200 with 4x FSAA and 16x AF. The Peak 2D mode was emulated by means of the 2D Transparent Windows test from PCMark05. This test is important as it simulates the user’s working with application windows whereas Windows Vista’s Aero interface uses 3D features.
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We had not expected the Sapphire HD 4850 X2 to be an economical solution, of course. Its peak power draw is indeed higher than 220 watts, being roughly similar to the total consumption of a CrossFire configuration built out of two Radeon HD 4850 cards plus the consumption of the PCI Express switch. Despite the differences in power circuit design, the distribution of load among the individual lines is very similar to what we saw with the Radeon HD 4870 X2: the 8-pin PCI Express connector was loaded the most.
The Sapphire HD 4850 X2 was not very hot, though. Catalyst Control Panel reported a temperature of about 40°C when idle and 62-64°C under 3D load. For the Leadtek WinFast GTX 280, the temperatures were 46°C and 73°C, respectively. Now let’s compare the amount of noise produced by each card.
The level of noise at a distance of 1 meter from the working testbed with a passively cooled graphics card inside was 43dBA. That’s the reference point for our measurements. And the results are far from good. The Sapphire HD 4850 X2 is one of the noisiest cards we have ever tested in our labs. Well, this might have been expected, as each of its GPUs produces 100 watts of heat which is to be dissipated by rather weak heatsinks. As a result, the cooling system has to make up for that by increasing the speed of the fans. And like with the Radeon HD 4870 X2, it is doing this smartly, changing the speed constantly to keep the GPUs cool. The fluctuations of speed can be easily heard even from a closed system case, and they are very irritating.
The Leadtek’s cooler produces little noise in 2D applications. When under load, the card can be heard among other system components, but its noise is not annoying. It sounds like a hissing of air and its level is constant. Thus, the card is far more agreeable for your ear than the Sapphire HD 4850 X2.
Thus, the Leadtek WinFast GTX 280 wins this round. This card has lower power consumption and heat dissipation but ensures more comfortable noise characteristics.
The battle field for Sapphire HD 4850 X2 2G/1G GDDR3 and Leadtek WinFast GTX 280 will be our new universal testbed configured as follows:
The graphics card drivers are configured in the same way as before: 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, and we used multisampling mode for both graphics architectures, because ATI solutions do not support supersampling for this function. As a result, our ATI and Nvidia driver settings looked as follows:
We made a lot of changes to the list of games and benchmarks we normally use for our tests. As a result, it currently includes the following titles:
First-Person 3D Shooters
Third-Person 3D Shooters
As before, 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. 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 Sapphire HD 4850 X2 2G/1G GDDR3 and Leadtek WinFast GTX 280 cards we have also included the following graphics accelerators to participate in our test session:
We ran our tests in the following resolutions: 1280x1024, 1680x1050, 1920x1200 and 2560x1600. The latter was only used for our today’s heroes and for ATI Radeon HD 4870 X2. Everywhere, where it was possible we ran the tests with enabled MSAA 4x antialiasing and anisotropic filtering 16x. 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. As we have already said, we didn’t modify the games configurations files.
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 2.9.6. In the latter case we ran the test three times and took the average of the three for the performance charts. We measured not only the average speed, but also the minimum speed of the cards where possible.
Well, let the battle begin!
The Sapphire HD 4850 X2 hits first. The card is 4-6% ahead of its opponent in every resolution save for 1680x1050 where the gap is as large as 16%. To be more specific, the two RV770 cores, even clocked at 625MHz and limited by the relatively slow memory, can maintain a higher bottom speed than the single G200 core. This advantage has practical value at the resolution of 2560x1600 where the Leadtek WinFast GTX 280 cannot deliver a comfortable frame rate.
The new Crysis is somewhat less heavy than its predecessor, yet the speeds are very low at the maximum level of detail, making you forget about playing at high resolutions. The opponents are equals in this test. Although the advantages of CrossFireX technology can be seen at the resolutions higher than 1280x1024, this cannot be viewed as a victory because the game is virtually unplayable at a frame rate of 11-20fps.
The frame rate is fixed at 30fps in this game as this is the rate at which all events are synchronized during networked play. We disabled this limit 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.
There is no clear winner here. Both cards are fast enough for comfortable networked play. The Leadtek is somewhat better at the low resolutions but the Sapphire goes ahead at 1920x1200 and higher display modes.
This is the first test where the Sapphire HD 4850 X2 enjoys a serious advantage over the Leadtek WinFast GTX 280: 32-33% at resolutions up to 1920x1200 and 23% at 2560x1600. However, both cards ensure the same comfort for the gamer because it is mostly determined by the bottom speed. The Sapphire has a much higher bottom speed at 1280x1024 but fails at 2560x1600: there is no talk about comfort if the frame rate can suddenly drop from 40 to 9fps.
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 enabled the DirectX 10.1 mode for the ATI cards.
The results are not high even at the reduced settings. The ATI Radeon HD 4870 X2 is the only card that can provide a playable frame rare at every resolution. As for the heroes of this review, the Leadtek WinFast GTX 280 gave up at 1920x1200 whereas the Sapphire HD 4850 X2 delivers a nearly comfortable speed at that resolution and slows down a little at 2560x1600. This should be counted in as a point for the red team.
Not a heavy application, Dead Space is predisposed to Nvidia’s solutions. It is the first test in which the Sapphire HD 4850 X2 is routed by its opponent, being 46-53% slower depending on the resolution. The reason can be guessed if you look at the low performance of the Radeon HD 4870 X2 and the good result of the Radeon HD 4870 1GB. So, CrossFire technology just does not work correctly or is incompatible with the game engine, which lowers the performance of the multi-GPU solutions. They do provide comfortable frame rates even at 2560x1600 but the problem is obvious. Hopefully, it will be solved with game or driver updates.
The Sapphire HD 4850 X2 feels the lack of fast memory its elder brother is equipped with, yet it is still ahead of the Leadtek WinFast GTX 280 at every resolution, including 2560x1600. The gap varies from 23 to 41% depending on the resolution. It should be noted, however, that the Leadtek card is quieter and consumes less power but provides the same level of comfort in this game. Thus, Nvidia’s approach to designing top-end graphics cards is viable, too.
The game does not allow to set Texture Quality at higher than Medium for graphics cards with 512MB of graphics memory whereas the maximum safe value of View Distance is 32. So, we had to select the mentioned values for our test. The other options were set at their maximums. 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 built-in test is not a good measure of the performance of today’s cards. We can only see a difference between the two opponents at 1920x1200 and 2560x1600. The Sapphire is 6% ahead at the former resolution and 10% behind its opponents at the latter resolution. This can be viewed as a draw, but the better noise characteristics of the Leadtek WinFast GTX 280 are an advantage.
The situation changes from test to test. Here, the ATI/Sapphire team is on the winning side, enjoying a 70% advantage over Nvidia/Leadtek at 1920x1200. However, the Leadtek WinFast GTX 280 offers a playable speed at every resolution, including 2560x1600, too. Note that the gap between the Sapphire HD 4850 X2 and the Radeon HD 4870 X2 is small in the first three resolutions, indicating that the memory bandwidth is not an important factor then. But it becomes decisive at 2560x1600.
There is tough struggle at 1280x1024 but the Leadtek WinFast GTX 280 proves to be unable to keep the frame rate higher than 25fps at 1680x1050 and higher resolutions. The Sapphire HD 4850 X2 gives up at 1920x1200 but wins the test anyway. The card’s high level of noise is the only downside.
The Sapphire HD 4850 X2 is 14 to 29% ahead of the Leadtek WinFast GTX 280 in the first three resolutions, both cards providing highest possible comfort. Moreover, the Leadtek may even seem preferable as it is a quieter and cooler card. However, the gap grows up to 58% at 2560x1600 which is a serious advantage. Once again we must acknowledge that ATI’s decision to use multi-GPU technology for top-end solutions was right and this approach works best at high resolutions such graphics cards are intended for.
The specific feature of this test is in wide fluctuations of the frame rate which can easily vary from 12 to 100fps depending on the scene. Neither of the two opponents has a bottom speed higher than 20fps at 2560x1600, so neither of them can be used to play the game at that resolution comfortably. As for the lower resolutions, the Leadtek can only provide a comfortable speed at 1280x1024 and the ATI/Sapphire team scores another point.
The game has a built-in frame rate limiter set at 30fps.
As we noted in our review dedicated to Red Alert 3, Nvidia’s solutions are significantly inferior to ATI’s in this game if you turn on FSAA. This is true for the current version of Nvidia’s driver, at least. And while this situation lasts, we can only recommend you to disable FSAA if you want to play the game on an Nvidia graphics card. The performance of the Sapphire HD 4850 X2 is affected by slow GDDR3 memory at 1920x1200 where its bottom speed sinks below playable.
The game has an integrated frame rate limiter set at 30fps. It doesn’t support FSAA.
This test does not give us useful information. All the cards hit the frame rate limit and do not differ much in terms of bottom speed. Perhaps we will replace this test with a more informative one in our future reviews.
The two opponents are roughly equal at resolutions up to 1680x1050, but the Sapphire HD 4850 X2 goes ahead at 1920x1200. Besides the 24% lead in average speed, the Sapphire can maintain a bottom speed of 25fps and higher. The Leadtek WinFast GTX 280 can’t match this performance. When it comes to the resolution of 2560x1600, neither card is capable of providing an acceptable bottom speed although their average frame rates are good enough.
The Sapphire HD 4850 X2 has a higher overall score, over 19,000 points, whereas the Leadtek WinFast GTX 280 only scores 17,000 points. These numbers have little practical value because 3DMark06 is a technically outdated benchmark, but let’s see what we have in the individual tests.
The Leadtek has no advantage even under favourable conditions. We mean the SM2.0 tests that have high-resolution textures and multiple light sources but little mathematics. The difference between the two opponents is only 761 points, though. That’s about 10%.
The mathematics-heavy SM3.0/HDR tests are easier for the Sapphire HD 4850 X2 which boasts 320 shader processors with 1600 ALUs. The card’s advantage grows up 1189 points as the consequence. The individual groups of tests agree with the overall picture. But 3DMark06 is an old benchmark already and we won’t publish the results of its individual tests in our future reviews.
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.
When the test runs at 1920x1200 with 4x MSAA, the Sapphire HD 4850 X2 is slower than the Leadtek WinFast GTX 280 because the latter has higher memory bandwidth.
Oddly enough, the Sapphire HD 4850 X2 is far slower not only than the Leadtek WinFast GTX 280 but also than the Radeon HD 4870 X2, at least at low resolutions. This may be due to the low frequency of its graphics cores. Besides, the Leadtek card can utilize the GPU’s computing resources for physical model calculations.
The second test puts a heavy load on the graphics card’s texture processors and the Sapphire card is superior in it. This is no wonder as we know that the G200’s 80 texture-mapping units perform similarly to 40 ordinary texture processors in real-life applications whereas the two TMU arrays of the Sapphire HD 4850 X2 work in sync, delivering double performance. The end result is limited by the card’s memory bandwidth as is indicated by the relative results of the Sapphire and the Radeon HD 4870 X2.
The fight between the two heavyweights – the Sapphire HD 4850 X2 and Leadtek WinFast GTX 280 – is over and it’s time to name the overall winner. Alas, the Leadtek left the ring without much glory. Having a comparable retail price, it is inferior to the Sapphire card in nearly each of our tests. The specifications of these cards coincide with those of the reference Radeon HD 4850 X2 and GeForce GTX 280, so we can acknowledge yet another defeat of Nvidia.
Let’s now discuss the fight in more detail.
At a resolution of 1280x1024 the Sapphire HD 4850 X2 wins nine tests, its advantage varying from 4 to 43%. It also has three draws and three losses, but only one loss is considerable (in Dead Space). We should acknowledge, however, that Red Alert 3 is the only game where the Leadtek WinFast GTX 280 failed completely. Otherwise, it is not much worse than the Sapphire in terms of delivering comfortable gaming conditions in most of the games. Moreover, the Leadtek card is quieter and thus more comfortable for your ears.
At the next resolution the Radeon HD 4850 X2 enjoys 11 wins and has only 1 draw and 3 losses. The average advantage over the GeForce GTX 280 grows from 10 to 16%. Besides Red Alert 3, Nvidia’s solution cannot deliver a comfortable speed in Mass Effect and X³: Terran Conflict.
If you have a 23 to 27-inch monitor, the choice is obvious: the Radeon HD 4850 X2 loses only in Dead Space due to the lack of support for CrossFire technology. It wins the rest of the tests confidently, enjoying an average advantage of 20% over the GeForce GTX 280. The only thing that can mar the victory is the high level of noise of the Sapphire card.
It is clear that the resolution of 2560x1600 pixels is a summit Nvidia’s single-PCB solutions are yet to conquer. This task lies with the upcoming dual-processor GeForce GTX 295. The current flagship GeForce GTX 280 ensures good speed in some games but is unable to compete with the Radeon HD 4850 X2. The Sapphire HD 4850 X2 is about 27% faster than the Leadtek WinFast GTX 280 on average but there were problems with bottom speed in Far Cry and the second GPU did not work in Dead Space.
So, the red team claims victory, but what is its price? With all its advantages, the Sapphire HD 4850 X2 2G/1G GDDR3 has two fundamental drawbacks. It has a poor design of the cooler, which leads to high level of noise. Moreover, the cooler doesn’t exhaust the hot air out of the system case. Your mainboard, hard drives and other components won’t like to have those 200 watts of heat staying inside. The support for four monitors simultaneously is an interesting feature, but we don’t think that many gamers will use it.
So, if you don’t mind the noise and your gaming system is roomy and well ventilated, the Sapphire HD 4850 X2 2G/1G GDDR3 may be a good buy because it is cheaper than the Radeon HD 4870 X2 but faster than the GeForce GTX 280 in most of today’s games. Otherwise, the Leadtek WinFast GTX 280 can make a good buy, too, especially if the card’s speed at the resolution of 2560x1600 pixels is unimportant for you.