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by Alexey Stepin , Yaroslav Lyssenko
06/05/2009 | 05:10 PM
We have always claimed and continue to do so that contemporary multi-GPU concept has a number of fundamental issues, some of which cannot be solved, at least not with where the corresponding technologies are today. Nevertheless, if homogeneous multi-GPU systems haven’t yet reached ultimate perfection, then they are at least extremely close to it already. Most newly emerged compatibility issues with the new gaming titles are being solved very quickly and the drawbacks that could be eliminated completed are long gone.
In the times of economic crisis when many gamers can’t afford to spend a lot of money on graphics cards, the value of compromise solutions increases dramatically. Multi-GPU systems built out of inexpensive mainstream graphics accelerators also belong to these solutions. We have already discussed several systems like that including Nvidia GeForce GTS 250 SLI, Radeon HD 4830 CrossFireX and Radeon HD 4670 CrossFireX. The first two demonstrated pretty decent potential, while the latter turned out too slow and didn’t prove up to our expectations: it failed to compete successfully against single-processor Radeon HD 4870 and GeForce GTX 260 Core 216.
But this industry continues to evolve and Radeon HD 4830 was eventually replaced with the new Radeon HD 4770. This new solution is based on the industry’s first graphics processor manufactured with 40nm process and became a real revolution in the budget sub-$100 graphics card segment, because it outperformed Radeon HD 4830 and yielded just a tiny bit to Radeon HD 4850. In fact, it not just turned out a gravestone for the former, but also announced the upcoming retirement of the latter, because the newcomer offered similar performance combined with excellent energy-efficiency and considerably lower production costs.
Taking into account all advantages this new solution has to offer, it is extremely interesting to see how well a CrossFireX configuration built of two graphics cards like that may perform. Theoretically, it should perform similarly to today’s best single-GPU graphics solution, like GeForce GTX 285 or Radeon HD 4890, or maybe even better than that. Together with relatively low price of this solution, all these advantages make it very attractive, especially for those who have already got one Radeon HD 4770 and are looking to improve the performance of their gaming platform at comparatively low cost. Things look really good in theory: by investing a little over $200 you can get graphics performance approaching the level of GeForce GTX 285, which is currently selling for $320-$350. But what do things look like in reality? We decided to investigate the performance of ATI Radeon HD 4770 CrossFireX tandem in order to answer this question. But before, let’s compare its technical specifications against those of its potential competitors.
Just like the majority of ATI Radeon HD models, Radeon HD 4770 supports up to four cards in CrossFireX configurations. The dual-card configuration is of primary interest to us, because it is the most affordable option that doesn’t require a specific mainboard with three of four PCI Express x16 slots. The specifications of a tandem like that look pretty impressive:
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Its computational power, RBE and video memory subsystems performance are almost twice as good as those of Radeon HD 4670 CrossFireX. And considerably higher frequencies of the graphics cores will most likely make up for the fewer ALUs and texturing processors compared with Radeon HD 4850 X2. Our today’s hero doesn’t look bad against the background of Nvidia solutions, either. However, it is fairly hard to make any assumptions here because of architectural differences between the computational units in ATI and Nvidia graphics cores. Moreover, TMU and RBE performance in Nvidia graphics cores is theoretically higher; however, as we all know, it doesn’t always guarantee victory in games. Therefore, we would like once again to refrain from making any assumptions at this point and wait for the results of our benchmarks instead.
The combined power consumption of two Radeon HD 4770 graphics cards is another trump of this CrossFireX configuration: it makes only 99W, which is solely due to fine 40nm manufacturing process. It is just a little higher than the corresponding reading of the Radeon HD 4670 CrossFireX tandem, and moreover, looks absolutely remarkable against the background of potential competitors, such as Radeon HD 4850 X2, for instance.
I would like to remind you that the actual numbers may be different from what you see above. First, we don’t yet have the ability to measure power consumption of two graphics cards working in a multi-GPU configuration, so the 3D readings are obtained as the power consumptions of single graphics cards added together. And secondly, even in 2D mode the power consumption of the secondary card never drops down to 0. Nevertheless, the numbers above are precise enough to give you a good idea of Radeon HD 4770 CrossFireX power consumption levels. At least, we can say with all certainty that you won’t need a high-capacity PSU for that.
Well, Radeon HD 4770 HD CrossFireX configuration looks very promising in theory. Now let’s see if it proves up to our expectations in practical tests.
We are going to investigate the gaming performance of the Radeon HD 4770 CrossFireX tandem in the following testbed:
The graphics card drivers were configured in the following way:
ATI Catalyst:
Nvidia GeForce:
We used the following synthetic benchmarks and games:
First-Person 3D Shooters
Third-Person 3D Shooters
RPG
Simulators
Strategies
Semi-synthetic Benchmarks
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 Radeon HD 4770 CrossFireX, we have also included the following graphics accelerators and multi-GPU systems to participate in our test session:
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 version 1.3 we used built-in game options that allow recording the original demo. Unfortunately, this approach doesn’t allow registering the minimal performance.
The budget Radeon HD 4770 CrossFireX tandem yields just a little bit to Radeon HD 4850 X2 (and obviously to Radeon HD 4850 CrossFireX configuration), but it is considerably ahead of all single-processor solutions participating in our today’s test session, including GeForce GTX 285. Moreover, it ensures pretty sufficient performance even in 2560x1600. Not bad, let’s see if this extremely interesting ATI solutions proceeds at the same pace.
But in the second test already the above described ATI tandem slows down, yielding to single-processor cards and falling considerably behind Nvidia GeForce GTS 250 SLI. Unfortunately, the performance of Radeon HD 4770 CrossFireX tandem is too low even in 1280x1024, so there is no practical value in it here. However, Nvidia solutions look just as good, because they can barely reach 20fps. There is hardly any difference between 15 and 20 fps: in both cases the gaming experience will be equally uncomfortable.
To ensure that we get extensive graphics cards performance report in Quake Wars we disabled the built-in average fps limiter in the game console. Since we use game’s built-in benchmarking options, there is no information about the minimal performance readings.
And as for Quake Wars, two inexpensive ATI graphics cards feel quite at home here, especially in 2560x1600 resolution, where Radeon HD 4770 CrossFireX is not just the fastest solution, but also has a significant advantage. It prevents instantaneous performance from ever dropping below 30 fps.
Two Radeon HD 4770 cards paired as a CrossFireX configuration perform pretty well, following closely behind Radeon HD 4850 X2 and ensuring acceptable results in up to 1920x1200 inclusive. The drop we observe in 2560x1600 must be connected with the specifics of CrossFireX operation. Insufficient video memory may not be the reason here, because Radeon HD 4850 X2 equipped with 1GB of video memory also shows very low results in this resolution. So, those of you who already have a monitor supporting high resolutions like that should probably go for a single GeForce GTX 275.
Things change again, and Radeon HD 4770 CrossFireX wins in three resolutions out of four. It yielded to GeForce GTX 285 only 8% in 2560x1600 resolution, but maintained sufficient average and minimal fps rates for comfortable gaming. Not bad at all for a multi-GPU tandem that costs only around $200.
This game is based on Source engine and has built-in benchmarking tools that report no minimal performance readings.
Due to higher GPU clock, Radeon HD 4770 CrossFireX manages to outpace Radeon HD 4850 X2 in all resolutions, and the first three – to successfully compete against GeForce GTX 285. Unfortunately, in 2560x1600 resolution our today’s main hero gives away its leading positions and starts losing to GeForce GTX 275. However, it still manages to maintain acceptable average performance level.
To achieve playable speed in this game we disabled FSAA and such resource-consuming options as Sun rays, Wet surfaces and Volumetric Smoke. We used the Enhanced full dynamic lighting (DX10) mode and additionally enabled the DirectX 10.1 mode for the ATI cards.
We didn’t expect Radeon HD 4770 CrossFireX to work any serious wonders here, but the results surprised us in a highly positive way. This configuration proved fats enough for 1680x1050 resolution and even for 2560x1600 with a few allowances. The only solution that could pose any serious competition to the ATI solution in question was GeForce GTX 250 SLI tandem.
Radeon HD 4770 CrossFireX system is beyond any competition in 1280x1024: it ultimately defeats all single-processor competitors and is 5% ahead of GeForce GTS 250 SLI. It acts a little more modest in the next two resolutions, either competing against GeForce GTX 285 in 1680х1050, or against Radeon HD 4890/GeForce GTX 275 in 1920x1200. However, in 2560x1600 our hero makes another leap forward and loses a little bit only to the noisy and not that cheap Radeon HD 4850 X2.
This is a true triumph of Radeon HD 4770 CrossFireX. It is the only other testing participant besides Radeon HD 4850 X2 that can ensure comfortable gaming experience in 2560x1600. Moreover, it boasts very impressive average performance in other resolutions, too.
The only drawback of dual-processor ATI solutions discussed today is their low minimal speed in 2560x1600 that is less than 25 fps. In all other cases they are way ahead of Radeon HD 4890, not to mention Nvidia solutions, of course.
This is where the difference in minimal performance between Radeon HD 4770 CrossFireX and Radeon HD 4850 X2 in 1680x1050 resolution is of primary interest to us. It could result from the difference in their memory subsystem organization, but we don’t see anything like that in any other resolutions, so we tend to believe that this fluctuation was caused by the manual fps rate measuring. As for the performance in general, unfortunately, Radeon HD 4770 CrossFireX application is limited to 1280x1024.
Radeon HD 4770 CrossFireX tandem is not any better or worse than any other contestants, yielding to them in one test and taking over in another. At least, it looks just as good as Radeon HD 4890 or GeForce GTX 275, but will undoubtedly cost less. Even the owners of large 30” monitors will not be disappointed.
We used the in-game benchmarking tools that do not allow measuring the minimal frame rate. We also enabled DirectX 10.1 support for ATI’s solutions.
It must be the amount of local graphics memory, which is only 512MB, that limits the potential of our hero in 2560x1600 resolution. However, in 1920x1200 it is ¼ ahead of the more expensive GeForce GTX 285, and in lower resolutions, it either outperforms the latter or yields to it insignificantly. The gaming is comfortable enough from my subjective standpoint, so two Radeon HD 4770 solutions may be a good choice for the flight sims fans.
The game has a built-in fps rate limiter locked at 30fps that cannot be disabled.
Radeon HD 4770 CrossFireX competes successfully against Radeon HD 4890 in 1280x1024 and 1680x1050, but in 1920x1200, not to mention 2560x1600, the budget CrossFireX tandem is not powerful enough. Nevertheless, it would be a good choice for Red Alert 3, especially keeping in mind how slow the competitor – Nvidia – solutions are in this game.
The recently released add-on to the original game does not introduce any technical innovations but contains a new plotline that allows you to play for the USSR.
Radeon HD 4770 CrossFireX yields substantially to Nvidia solutions in up to 1680x1050 inclusive, but in 1920x1200 it evens the score at a pretty comfortable performance level. You will be disappointed with the Radeon HD 4770 CrossFireX tandem performance in 2560x1600, but all other today’s testing participants are no better there either.
The parity between Radeon HD 4770 CrossFireX with a $200 price tag and Radeon HD 4850 X2 looks really impressive especially since the difference of 100 points is pretty negligible in this case. Moreover, RV740 tandem runs even faster in SM2.0 tests due to higher clock frequency. However, the defeat in SM3.0/HDR tests caused by lower computational power eats up the advantage resulting into even total score.
We minimize the CPU’s influence in 3DMark Vantage 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 performance in 3DMark Vantage is not so impressive because PhysX acceleration is not supported. However, Radeon HD 4770 CrossFireX managed to get considerably far ahead of the single Radeon HD 4890 and fell just a little behind GeForce GTX 275.
The results of individual benchmarks prove everything we have just seen: Radeon HD 4770 CrossFireX barely yields to Radeon HD 4850 X2 but is convincingly ahead of Radeon HD 4890. It is also evident that our hero feels best in lower resolutions, where memory subsystem and RBE performance have minimal effect on the final speed. However, it manages to outpace GeForce GTX 275 in the second test, even in 1920x1200, due to higher computational capacity.
So what can we say in conclusion to our today’s test session of the budget Radeon HD 4770 CrossFireX tandem? First, we have once again proven that the days of Radeon HD 4850, not to mention Radeon HD 4830, are numbered. And it doesn’t matter if we are talking about two discrete graphics card or about a rare and expensive Radeon HD 4850 X2 – in most cases two Radeon HD 4770 cards in CrossFireX configuration are just a tiny bit behind, no more than 1-3% on average. Second, we see an evident advantage over a single Radeon HD 4890, at least when the GPU frequency is at 850MHz. And finally, third, two Radeon HD 4770 are a very dangerous rival to single-GPU Nvidia solutions on G200b core, especially GeForce GTX 275 that is somewhat slower than GeForce GTX 285.
But let’s take a look at the detailed charts for each resolution separately:
Strange as it might seem, Radeon HD 4770 CrossFireX falls most behind Radeon HD 4850 in 1280x1024. The gap between them makes 3.5% on average and in some cases, like Prince of Persia and Mass Effect it may reach up to 9-10%. But it is much more interesting to compare our today’s hero against Radeon HD 4890 and GeForce GTX 285: in the first case the average advantage if Radeon HD 4770 CrossFireX makes 18%, and in the second - 8%.
Dual-processor ATI solution loses to a single-GPU Nvidia card only in five tests out of fifteen. The most serious defeat takes place in Enemy Territory: Quake Wars.
In 1680x1050 resolution Radeon HD 4770 CrossFireX falls 19% behind Radeon HD 4890 and 9% behind GeForce GTX 285. In the former case, the dual-processor solution loses in three tests, while in the latter – in six. However, the only title where it may cause any problems for comfortable gaming is Crysis Warhead, because in all other cases the performance remains within comfortable range. Radeon HD 4770 CrossFireX tandem not just proves worthy, but does it really brilliantly, especially due to its low price and the opportunity for gamers to purchase cards separately.
Radeon HD 4770 CrossFireX platform evens the score with Radeon HD 4850 X2 almost eliminating the difference – it got as low as 1%. However, the advantage over single-GPU rivals drops down to 13% for Radeon HD 4890 and to 8% for GeForce GTX 285. In the latter case the score is again 9:6 in ATI’s favor and even the lost games won’t cause any problems for the users. You will anyway need something more powerful than GeForce GTX 285 for Crysis Warhead, while in all other games two Radeon HD 4770 cards will provide subjectively sufficient gaming comfort.
This is the triumph of ATI Radeon HD 4770 CrossFireX: in this resolution it manages to tie with single-processor solutions. In fact, it is not quite a tie: for example, our tandem yielded quite tangibly to Radeon HD 4890 in Crysis Warhead, Far Cry 2, Fallout 3, Race Driver: GRID, Red Alert 3: Uprising, Left 4 Dead and World in Conflict: Soviet Assault. Although we could disregard the first two games here, in Fallout 3 and RA3: Uprising we have already come across the situations when performance dropped below acceptable levels. Compared with GeForce GTX 285, our hero did in fact lose in Crysis Warhead and Far Cry 2,and also in F.E.A.R. 2: Project Origin, Left 4 Dead and World in Conflict: Soviet Assault.
It is hard to imagine that an owner of a monitor supporting 2560x1600 resolution could be interested in getting a dual- Radeon HD 4770 CrossFireX configuration – as a rule, he or she either already has a more powerful solution or is planning to get one. But nevertheless, our today’s hero demonstrated very good results in this resolution that is in fact not intended for it initially. We don’t have the opportunity to check out graphics cards performance in all existing games, but at least we can state with all certainty that Radeon HD 4770 CrossFireX tandem will ensure comfortable gaming experience in 2560x1600 resolution even with maximum image quality and enabled FSAA 4x in the following titles: Call of Duty: World at War, Enemy Territory: Quake Wars, F.E.A.R. 2: Project Origin, Left 4 Dead, Devil May Cry 4, Prince of Persia and Race Driver: GRID.
Overall Radeon HD 4770 CrossFireX is a very promising and interesting solution that definitely has the right to be there. Buying a second Radeon HD 4770, if you already have one, may be an excellent and most importantly inexpensive way of increasing your system’s gaming performance significantly if you have a mainboard that supports two ATI Radeon HD graphics cards in CrossFireX mode. We didn’t reveal any stability, image quality or compatibility issues during our test session. Nevertheless, we have to remind you that we cannot cover all existing games and proper functioning of ATI CrossFireX technology, as well as of Nvidia SLI, is directly connected with the software driver optimizations. That is why you’d better make sure that your multi-GPU solution of choice supports your favorite games, before you buy it. Otherwise, you may end up waiting for the new driver version supporting your game for a long time and there is always a chance that your wait may not be rewarded after all.