by Yaroslav Lyssenko
04/08/2011 | 12:03 PM
What's better, to link two inexpensive graphics cards in a single subsystem or buy one top-end card for the same money? This depends on the particular circumstances, of course. Perhaps you already have Nvidia's newest affordable solution GeForce GTX 550 Ti but you think it to be not fast enough in certain applications. Or you may have some $300 to spend and a mainboard with two PCI Express x16 slots. In either case the choice is hard considering the abundance of different offers in the graphics card market.
Judging by the specifications, a couple of GF116-based cards look a very appealing solution: the GPU clock rate is the highest among the competing offers. The same goes for the peak memory bandwidth which is almost as high as 200 GBps. Alas, such a high performance doesn’t come without certain downsides. The fastest graphics subsystem you can get for $300 would also have a high heat dissipation of 240 watts. Although lower than that of the GeForce GTX 590 or Radeon HD 6990, this number means very, very hot.
AMD users can hardly hope the Radeon HD 6950 to match the performance of a GeForce GTX 550 Ti SLI configuration. The single weakness this SLI tandemmay betray is in its rendering of scenes that require high texture-mapping performance. So, that’s the theoretical background behind our today's tests.
In our previous review we benchmarked a very nonstandard GF116-based product but today we've got a less extraordinary, yet quite interesting solution from Zotac.
The product box is painted Zotac’s traditional mix of yellow, brown and black. It is embellished with a picture of a dragon.
A few years ago graphics card makers were trying to attract the customer with various extra accessories. This trend has changed and recent products generally come with a bare minimum of accompaniments.
So, there is nothing special about these accessories save for the Zotac Boost Premium software suite that includes various tools for editing and recording videos and photos and virtually transforming your computer into a multimedia center.
Ours is not a trivial version of the graphics card, by the way. It is a special AMP! Edition and its GPU and memory clock rates are higher than those of the standard GeForce GTX 550 Ti. Zotac lifted the GPU frequency by 12% (to 1000 MHz) and the GDDR5 frequency by 300 MHz (to 4400 MHz). The memory bus is still 192 bits wide. The total amount of the onboard graphics memory is 1024 megabytes.
The graphics card supports SLI and has an appropriate connector. Compared to the MSI GeForce GTX 550 Ti, the Zotac looks smaller and kind of simpler. Except for the original cooling system, we can't see any serious differences from the reference sample.
Zotac's engineers took a simple cooler for this card since the peak power consumption of the GeForce GTX 550 Ti is declared to be only 116 watts. The aluminum heatsink takes up about half the PCB and is fastened with four screws. We will check out the performance of this cooler shortly to see how it copes with the pre-overclocked GTX 550 Ti.
Taking the heatsink off, we can see a copy of Nvidia’s reference GTX 550 Ti. The GF116-400-A1 chip is surrounded by six Hynix H5GQ2H24MFR memory chips with a rated frequency of 1250 (5000) MHz.
The power system of the Zotac GeForce GTX 550 Ti AMP! Edition is the same as the reference card’s. Nvidia’s engineers should be given credit for implementing a four-phase power circuit which turns out to be sufficient even for the pre-overclocked product from Zotac.
The connectivity options provided by the Zotac card are somewhat broader than those of the above-mentioned MSI: two DVI-I ports, one HDMI, and a DisplayPort. With so many connectors, you can hardly have any problems hooking this card up to your monitor and/or TV-set.
Now it’s time to check out the ability of Zotac's original cooler to cope with the pre-overclocked GeForce GTX 550 Ti.
Unfortunately, the cooler is far from perfect. The GF116 chip itself isn’t very hot but the increased clock rates and the rather small heatsink lead to a very high GPU temperature. Having a temperature of only 28°C at low loads, the GPU of the Zotac card is as hot as 84°C at full load.
When running 2D applications, the Zotac is not louder than our lab’s background noise. But when a 3D application is launched, it becomes quite audible at 57 dBA (if measured at a point near the testbed). Noise perception is subjective, of course, and in this particular case, although the noise level is high in decibel, the card is not really irritating.
The high GPU temperature and the high level of noise are indicative of the low performance of the Zotac cooler. It affects the card's overclockability, too. Our sample could only work at GPU and memory frequencies of 1020 and 4840 MHz, respectively. This is far from breaking any records, but the card comes pre-overclocked anyway.
We are going to investigate the gaming performance of Zotac GeForce GTX 550 Ti AMP! Edition using the following universal testbed:
We used the following ATI Catalyst and Nvidia GeForce drivers:
The ATI Catalyst and Nvidia GeForce graphics card drivers were configured in the following way:
Below is the list of games and test applications we used during this test session:
First-Person 3D Shooters
Third-Person 3D Shooters
Semi-synthetic and synthetic benchmarks
We selected the highest possible level of detail in each game. If the application supported tessellation, we enabled it for the test session.
For settings adjustment, we used 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 ran our tests in the following resolutions: 1600x900, 1920x1080 and 2560x1600. Unless stated otherwise, 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.
Besides Zotac GeForce GTX 550 Ti AMP! Edition, we also tested the following products:
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 3.3.3. In the latter case we ran the test three times and took the average of the three for the performance charts.
The duo of affordable graphics cards takes a good start in our tests. The effective game profile in the driver allows the GeForce GTX 550 Ti SLI subsystem to match the performance of the more advanced GeForce GTX 570. SLI technology boasts a scalability of 80-90% here butthe frame rate remains rather low due to the high system requirements of Aliens vs. Predator. The game is not playable at resolutions above 1600x900 pixels unless you lower its graphics quality settings.
When overclocked, our Zotac GeForce GTX 550 Ti AMP! Edition delivers over 30 fps in single-card mode, yet this frame rate is still not high enough for a first-person shooter.
The second test brings a second victory to the GeForce GTX 550 Ti SLI configuration which outperforms the closest rival GeForce GTX 570, even though by a mere 3 fps in some display modes. This game is playable with comfort at resolutions up to 1920x1080.
The factory overclocking doesn’t help the Zotac in single-card mode. You’ll have to turn off some visual options if you want to play Battlefield: Bad Company 2 Vietnam on a single Zotac GeForce GTX 550 Ti AMP! Edition with comfort.
Even a single GeForce GTX 550 Ti is good enough for running the latest version of Call of Duty: Black Ops. No wonder that the SLI configuration easily copes with that, too. It also outperforms both the GeForce GTX 570 and the Radeon HD 6950, but each of these cards delivers a playable frame rate as well.
The overclocked frequencies of the Zotac card add some more reserve of speed at 2560x1600 so that you didn’t worry about occasional slowdowns even if you are playing with FSAA turned on.
Nvidia’s programmers have been optimizing their SLI technology for a few years already and here’s the result: the scalability of the SLI tandem amounts to 80-90% in Crysis Warhead. The GeForce GTX 550 Ti SLI is comparable to the GeForce GTX 570 at 1600x900 but both are outperformed by the Radeon HD 6950 at the higher resolutions (the leader's frame rate of 20 fps is far from comfortable, though).
The extra 100 MHz of clock rate do not help the Zotac card cope with Crysis Warhead. You have to lower the graphics load by disabling FSAA and/or shadows to have a comfortable frame rate.
This game is tested with the tessellation option turned on.
The GeForce GTX 550 Ti SLI configuration doesn’t feel at its ease in the Moscow underground. Its scalability is rather low, so the tandem takes fourth place, after the GeForce GTX 570, Radeon HD 6950 and, rather alarmingly, GeForce GTX 560 Ti. If you are into this game, you may want to wait until Nvidia releases a more effective driver before you build a SLI tandem to play it.
The pre-overclocked card from Zotac is almost 20% faster than the regular GeForce GTX 550 Ti in Metro 2033 but, like in the previous game, you will have to step down your graphics quality settings to play with comfort.
This game runs with enabled tessellation.
The Zone is a more favorable environment for the SLI tandem which is 80-90% faster than the single card and competitive against the GeForce GTX 570 and Radeon HD 6950. Unfortunately, the GeForce GTX 550 Ti will not allow you to play comfortably at 2560x1600 notwithstanding the rather old graphic engine of this game.
The Zotac card outperforms the reference GeForce GTX 550 Ti by about 16% here.
Just Cause 2 reveals the downsides of the multi-GPU configuration. The GeForce GTX 550 Ti SLI is only 20 to 30% faster than the single such card and falls behind the GeForce GTX 560 Ti, let alone the more advanced solutions.
On the other hand, this test highlights the benefits of the pre-overclocked Zotac card which stays halfway between the single GeForce GTX 550 Ti and the SLI tandem.
We’ve got an interesting picture here. The SLI scalability is quite high at 60-70%, yet this only helps our SLI tandem match the GeForce GTX 560 Ti.
The single card from Zotac is close to the Radeon HD 6950 at 1600x900 but falls behind at the higher resolutions.
Dragon Age IIhas been included into our list of tests but recently, yet the ForceWare driver can effectively parallel computations between the two GPUs of our SLI configuration. On the other hand, the game is obviously optimized for AMD solutions, so the Radeon HD 6950 is unrivalled. As for the GeForce GTX 550 Ti SLI, it shares second place with the GeForce GTX 570 at low resolutions and loses its ground in the higher display modes.
As we saw in earlier reviews, Dragon Age II does not differentiate between GeForce GTX 550 Ti and 560 Ti. Therefore the Zotac GeForce GTX 550 Ti AMP! Edition leaves the 560 Ti behind despite their considerable architectural differences.
We enforced full-screen antialiasing using the method described in our special Mass Effect 2 review.
We’ve got record-breaking scalability of SLI in this test even though it can only be really necessary for nonstandard highest-resolution panoramic display modes. The GeForce GTX 550 Ti SLI tandem easily beats every opponent and allows playing this space odyssey comfortably at the highest resolution of 2560x1600.
The 10% increase in speed the Zotac card enjoys thanks to its pre-overclocked frequencies doesn’t help it reach the level of the GeForce GTX 560 Ti.
There are large gaps between products from different classes in this racing sim. The best that our SLI tandem of GeForce GTX 550 Ti cards can do is overtake the GeForce GTX 560 Ti.
The game runs rather fast even on the single Zotac card, though. On the other hand, we can see that it certainly prefers a more advanced GPU architecture to a higher GPU clock rate.
The struggle is quite fierce in this test: the GF116-based SLI tandem matches the GeForce GTX 570 at 1600x900 and wins at 1920x1080 but the GTX 570 then beats the SLI configuration at 2560x1600.
The Zotac card is 17% ahead of the reference sample, yet still cannot catch up with the GeForce GTX 560 Ti.
Here is another recent addition to our list of tests. Unfortunately, the latest installment in the famous Total War series is not compatible with SLI technology. Hopefully, Nvidia will solve this problem with the next ForceWare release.
You have to lower your graphics quality settings or choose a faster graphics card than the Zotac GeForce GTX 550 Ti AMP! Edition in order to play Total War: Shogun 2 comfortably.
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 resolutions.
Our SLI tandem has no problems in the synthetic benchmarks. It scores over 10,000 points, joining the leaders GeForce GTX 570 and Radeon HD 6950. The scalability of the SLI technology amounts to 100% here. This test is indicative of what a GeForce GTX 550 Ti SLI configuration can do if the graphics driver effectively uses both graphics cards in parallel.
The single Zotac card is not very impressive, though. It is only 7% faster than the reference sample.
Like in the real games, our SLI tandem is slightly slower than the GeForce GTX 570. The Radeon HD 6950 is also very close, ready to overtake the GeForce GTX 550 Ti SLI as soon as it fails but a little.
The Zotac GeForce GTX 550 Ti AMP! Edition shows that 3DMark Vantage is rather indifferent to the GPU clock rate. We’ve seen the same in F1 2010.
We use the Extreme profile here. As opposed to 3DMark Vantage, this profile uses a resolution of 1920x1080 pixels.
The more recent version of 3DMark produces the same standings. The GeForce GTX 570 is first, followed by the SLI tandem. The AMD solution is 4% slower than the SLI configuration.
The higher loads of 3DMark 11 emphasize the benefits of the Zotac card, so we can see it outperform the reference sample by 10%.
This benchmark makes wide use of tessellation to render the surface of the earth. The number of polygons per one frame can be as high as 1.5 million!
Interestingly enough, the GeForce GTX 550 Ti SLI takes first place at the highest resolution only, although in the previous tests it looked preferable in the lowest display modes. The SLI scalability is only 50%, so the SLI configuration might do better with a more optimized driver.
The pre-overclocked Zotac adds to the performance of the reference card, especially at 2560x1600.
We use Normal tessellation in this test.
The last test in this review is where the GeForce GTX 550 Ti SLI shows its best scalability. It is over 120%, actually. Unfortunately, we didn't see that in the gaming tests. And even here, the SLI tandem cannot beat the GeForce GTX 570 or the Radeon HD 6950.
On the other hand, this test highlights the advantages of the Zotac card which is 22% faster than the reference sample.
Just as you might have inferred from the specifications table at the beginning of this review, the GeForce GTX 550 Ti SLI configuration is indeed a viable solution for a gaming computer, yet there are a number of things that you must take into account in case you really want to build one for yourself.
First of all, you should make up your mind as to what games you are going to play. Unfortunately, the efficiency of any modern multi-GPU technology depends on the graphics driver's ability to effectively parallel computations between the two GPUs. Thus, everything depends on software optimizations.
Second, you need a mainboard with two graphic slots which may be costlier than a mainboard with only one such slot.
Anyway, if you really want to try a configuration with two GeForce GTX 550 Ti cards, here is what you can expect from it in games:
At a resolution of 1600x900, the average advantage of the SLI tandem over the single-processor GeForce GTX 570 varies from -70 to +22%. The large dispersion is due to the lack of SLI support for Total War: Shogun 2 in Nvidia’s latest driver. Apart from this failure, the two solutions are rather similar to each other. We'd prefer the single GeForce GTX 570 since it helps achieve the same performance with less trouble.
Except for Total War: Shogun 2, the Radeon HD 6950 is an average 20% slower.The price wars of the GPU developers are constantly changing the market situation, yet AMD will be unable to compete with the pair of GF116-based products unless the Radeon HD 6970 steps down into the lower category.
Surprisingly enough, there are but few changes when we switch to the resolution which is perhaps the most popular today. The GeForce GTX 550 Ti SLI cannot beat the GeForce GTX 570 and enjoys the same lead over the Radeon HD 6950. The summary diagram makes it clear how greatly the performance of a particular solution depends on the selection of test applications.
So, if you've already got a GF116-based card, purchasing a second one is quite a good way to upgrade. Spending $149 for a second GeForce GTX 550 Ti, you get the performance of a GeForce GTX 570. Of course, the first card cost you some money as well, but you can hardly return it to the seller at the same price. Selling your GTX 550 Ti, adding $149 and buying a GTX 570 ishardly possible.
But if you are building a new system and choosing between a GeForce GTX 550 Ti SLI setup and a single GeForce GTX 570, you may want to prefer the latter because it offers the same performance with fewer risks. Moreover, it would allow you to eventually upgrade to a GeForce GTX 570 SLI configuration if necessary.
GeForce GTX 550 Ti cards come from different brands in different versions. Zotac's is a rather conventional offer. This card comes with a minimum of accessories but offers higher frequencies instead of free software or fridge magnets.
The Zotac GeForce GTX 550 Ti AMP! Edition is going to be a good buy for every user who values speed above everything else. The warranty-covered factory overclocking is the key advantage of this product. However, it's up to you to decide whether its 16% increase in speed is worth the increased level of noise. The Zotac card is fast enough to allow you to play most of today’s games at the highest graphics quality settings.