2-Way SLI Performance: Palit GeForce GTX 770 JetStream and Zotac GTX 770 AMP! Edition Graphics Cards Review

Two graphics cards on enhanced PCBs, with increased clock speeds and unique cooling systems will not only compete against one another in our today’s test session, but will also stand in a 2-way SLI configuration against a dual-GPU GeForce GTX 690.

by Sergey Lepilov
08/05/2013 | 05:34 AM

 As soon as the Nvidia GeForce GTX 770 was announced, each and every Nvidia partner rolled out its own version of this highly interesting graphics card. All of them try to attract the customer with an improved PCB, original cooler, increased clock rates or some other special features. The products from Palit Microsystems Ltd. and Zotac International (MCO) Ltd. have been the first to arrive to our test labs. Of course, we are going to receive and test other brands’ products as well, but today we're talking about the Palit GeForce GTX 770 JetStream 2GB and the Zotac GeForce GTX 770 AMP! Edition 2GB. Besides our traditional tests of performance, temperature, noise level and overclocking potential, we will also benchmark them in 2-way SLI mode to check out the efficiency of the SLI technology as applied to the newest solutions from Nvidia. 

Technical Specifications Overview


We are going to start with an overview of the technical specifications on the two graphics cards discussed in this article: Palit GeForce GTX 770 JetStream and Zotac GTX 770 AMP! Edition. We will compare them side by side against the specs of the reference Nvidia GeForce GTX 770:


Testing Participants

Palit GeForce GTX 770 JetStream 2GB

The GeForce GTX 770 JetStream 2GB card from Palit is shipped in a huge box painted black and gold. Some basic information about the product can be found on the front of the packaging. Nvidia’s technologies are described on the back of the box.


The top of the box can be flipped open to reveal the card through a plastic window. You can also find a detailed description of the benefits of Palit's exclusive cooling system here.

The accessories include a power adapter, an HDMI->DVI adapter, a DVI->CRT adapter, an installation guide and a CD with drivers and utilities.

There are no extras in the box, but Palit has never been among those who indulge their customers with freebies. The Palit GeForce GTX 770 JetStream 2GB is manufactured in China and costs $429, which is $30 more expensive than the recommended price of the GTX 770. The warranty period is 2 years.

The new card from Palit has an unconventional appearance. We've seen coolers with three fans before, but the central fan here is larger than the other two and is additionally edged with golden plastic inserts, producing a rather attractive image:

The card is 285x129x49 millimeters, so it is not only 18 mm longer but also 10 mm thicker than the reference GeForce GTX 770. You should note this if you're going to build a SLI tandem out of two such cards.

The selection of video interfaces is perfectly standard: dual-link DVI-I and DVI-D ports, an HDMI 1.4a, and a DisplayPort 1.2.

Two MIO connectors for combining two, three or even four graphics cards into a SLI subsystem can be found in their conventional location.


The Palit GeForce GTX 770 JetStream 2GB is equipped with one 8-pin and one 6-pin power connector. Its specified power draw is 229 watts, which is 1 watt less than required by the reference GeForce GTX 770 despite the pre-overclocked GPU. Does it mean that Palit has managed to develop a more economical PCB? Well, the PCB differs from the reference design indeed:

Instead of the standard 5+1+1 power system, the Palit GeForce GTX 770 JetStream 2GB has eight power phases, based on solid-state DrMOS transistors, for the GPU and a couple of phases for the graphics memory and PLL.

The GPU power system is managed by an eight-channel controller ON Semiconductor NCP 4208.

So, the power system has been improved to ensure more stability at increased clock rates. Overclockers will also appreciate the fact that the card offers check points on the reverse side of the PCB to let you accurately measure GPU, memory and PLL voltages.

The 28nm GK104 die is revision A2 and was manufactured in Taiwan on the 13th week of 2013.

Its base clock rate is increased to 1150 MHz in 3D applications (+10%), reaching up to 1202 MHz in Boost mode. During our tests, at the maximum Power and Temperature targets, the GPU clock rate would peak up to 1254 MHz. In 2D applications the GPU clock rate is dropped to 135 MHz and its voltage is lowered from 1.2 to 0.85 volts.

Like the reference Nvidia GeForce GTX 770, the Palit GeForce GTX 770 JetStream comes with 2 gigabytes of GDDR5 memory in eight FCBGA-packaged chips soldered to the face side of the PCB. These are K4G20325FD-FC28 chips from Samsung Semiconductor.


The memory frequency doesn't differ from the reference card's: 7012 MHz in 3D applications and 648 MHz in 2D applications. Thus, the Palit GeForce GTX 770 JetStream has the following specs:

The GPU of our sample of the Palit card has an ASIC quality of 82.5%.

The card's cooling system consists of three main parts: an aluminum heatsink with five 6mm copper heat pipes responsible for the GPU, a steel heat-spreading plate on the memory chips and power system components, and a plastic casing with fans:

The heatsink has two sections. The bigger section is pierced by the two middle pipes and the smaller, by the remaining three.

The heat pipes seem to be fastened to the cooler’s copper base with thermal glue. The heatsink fins are simply press-fitted on the pipes, which may have a negative effect on the overall performance of the cooler.

The heat-spreading plate contacts with graphics card components by means of thermal pads and, like the main heatsink, is cooled by the fans.

There are two types of fans here, both manufactured by Power Logic. The central 92mm fan has translucent blades and blue highlighting. The other two fans are 80 mm in diameter and simpler in design:


The speed of the main fan is PWM-regulated. Judging by the connection type, the other two fans are regulated by changing their voltage. We don’t know which exactly fan is used for monitoring, but the card's monitoring data indicate that the fan speed varies from 780 to 2730 RPM.

To check out the cards temperatures we used five runs of the pretty resource-hungry Aliens vs. Predator (2010) benchmark at the highest visual quality settings, at a resolution of 2560x1440 pixels, and with 16x anisotropic filtering and MSAA 4x.

We used MSI Afterburner 3.0.0 beta 10 and GPU-Z version 0.7.1 for monitoring of temperatures inside the closed system case, which configuration is discussed in detail in the corresponding chapter of the roundup. All tests were performed at 25°C room temperature.

Now let’s check out the efficiency of the cooler installed on the Palit GeForce GTX 770 JetStream when its fans are regulated automatically:

The peak GPU temperature was 80°C during this test and the fans only accelerated to 1650 RPM. We’ll check out the noise factor shortly but we can already say that the cooler is efficient, considering the pre-overclocked GPU.

At the maximum speed of the three fans, the GPU temperature was 11°C lower at only 69°C.

So we can see that the cooler's performance depends on the speed of its fans.

Checking out the card’s overclocking potential, we managed to increase its GPU and memory clock rates by 60 and 920 MHz, respectively.

The resulting clock rates were 1210/1262/7932 MHz:

The GPU clock rate would peak to 1306 MHz during the temperature test, though:

We can note that the GPU is still no hotter than 80°C thanks to the fans accelerating to 1740 RPM.

ZOTAC GeForce GTX 770 AMP! Edition 2GB

The GeForce GTX 770 AMP! Edition from Zotac is packed into a smaller box than the Palit, yet the box is still surprisingly large for a graphics card. There is no flip cover here, but you can read quite a lot of information about the product from the front and back of the packaging.


The accessories include two power adapters, a CD with software, a user manual, a Zotac sticker, and a Splinter Cell Compilation coupon.

Manufactured in China, the GeForce GTX 770 AMP! Edition is shipped with a 5-year warranty for $449, which is 12.3% higher than the recommended price of the GeForce GTX 770.

The Zotac is smaller than the Palit: 10 mm shorter and 10 mm narrower. So it seems to be a better choice for multi-GPU configurations. The entire face side of the PCB is covered with a figured metal casing with two bright orange fans.


The Zotac has the same video connectors as the Palit or the reference GeForce GTX 770 but the vent holes in its mounting bracket are large so that the hot air could be better exhausted from the computer case.

The Zotac is not original in its MIO and power connectors, either:


A 600-watt PSU is recommended for a computer with one such card.

The PCB resembles the Zotac GeForce GTX 680 AMP! Edition but with the complete set of power transistors.

The power system follows the 5+2 formula with five phases for the GPU and 2 phases for the graphics memory and PLL.

It is managed by a five-phase RT8802A PWM controller  from Richtek Technology which is located on the reverse side of the PCB.

The Palit seems to have a more advanced power system than the Zotac.

The GPU is the same revision as Palit’s but was manufactured 4 weeks earlier (9th week of 2013).

The clock rates (1150/1202 MHz) and the rest of the specs are the same as those of the above-discussed Palit GeForce GTX 770 JetStream. Notwithstanding the same memory chips, the memory frequency of the Zotac card is increased to 7200 MHz.


The resulting memory bandwidth is as high as 230.4 GB/s, so the Zotac GeForce GTX 770 AMP! Edition should have an edge over the Palit GeForce GTX 770 JetStream:

The ASIC quality of the GPU die is almost the same at 81.0%.

Zotac’s cooler is called Dual Silencer. It consists of an aluminum heatsink with heat pipes, a couple of fans, and a metallic casing.

There are individual aluminum heatsinks with thermal pads on the memory chips and power transistors. The heatsink has five heat pipes, two of which are 8 mm in diameter. The three remaining pipes are 6 mm in diameter.

As opposed to the Palit's cooler, the pipes are soldered to the heatsink, and in a very neat way. The heatsink is cooled by two 70x10mm fans from FirstD:

Their speed is PWM-regulated in a range of 1000 to 3300 RPM. In our temperature test the speed was 2160 RPM when the fans were regulated automatically.

The peak GPU temperature was 81°C. Considering the same GPU clock rates and ASIC quality, the Zotac cooler is not better than the Palit one. It is 3°C worse at the maximum speed of the fans:

Still, the Dual Silencer is quite good at its job.

The Zotac GeForce GTX 770 AMP! Edition doesn’t have high overclocking potential. Its GPU could be overclocked by a mere 35 MHz and its memory, by 580 MHz.

The resulting clock rates were 1185/1237/7780 MHz. The Palit card reached higher frequencies in our tests.

The peak GPU temperature of the overclocked Zotac was 82°C, its fans rotating at 2220 RPM.


Noise Level

The noise level of each cooler was measured between 1:00 and 3:00 AM in a closed room about 20 m2 big using CENTER-321 electronic noise meter. The noise level for each cooler was tested outside the system case when the only noise sources in the lab were the cooler and its fan. The noise meter was installed on a tripod and was always at a 150 mm distance from the cooler fan rotor. The tested cooling systems were placed at the edge of the desk on a sheet of polyurethane foam. The lowest noise reading our noise meter device can register is 29.8 dBA and the subjectively comfortable noise level in these testing conditions was around 36 dBA (do not mix it up with low noise level). The fan(s) rotation speed was adjusted in the entire supported range using our precise in-house controller by changing the voltage with 0.5 V increment.

We will compare the noise level of the Palit GeForce GTX 770 JetStream and Zotac GeForce GTX 770 AMP! Edition with that of the reference GeForce GTX 770 from Nvidia. The top speed of the fans they reach when regulated automatically is indicated with vertical dotted lines.

First of all, none of these cards can be called really quiet. Each of them is not just audible against the background noise of our rather quiet computer but downright loud. The Palit GeForce GTX 770 JetStream is the noisiest of the three, surpassing the reference cooler from Nvidia and being barely comfortable in 2D applications. The Zotac GeForce GTX 770 AMP! Edition is indeed quieter than the reference sample but not by much. At speeds above 2200 RPM the Zotac is noisier than the Nvidia. It is, however, the quietest of the three cards in 2D applications, which is important even for gamers.

Power Consumption

We measured the power consumption of our testbed equipped with different graphics cards using a multifunctional Zalman ZM-MFC3 panel which can report how much power a computer (without the monitor) draws from a wall outlet. There were two test modes: 2D (editing documents in Microsoft Word or web surfing) and 3D. In the latter case the load was created by four runs of the introductory “Swamp” scene in Crysis 3 game at 2560x1440 with maximum image quality settings, but without MSAA.

Besides the cards from Zotac and Palit and the reference Nvidia GeForce GTX 770, we’ve included into this test a configuration with an overclocked dual-processor Nvidia GeForce GTX 690 (we’ll explain the reasons for its overclocking shortly). Here are the results:

There is only a 26-watt difference between the configurations with the reference Nvidia GeForce GTX 770 and the pre-overclocked Zotac. On the other hand, the Zotac needs 5 watts more than the reference GTX 770 when the latter is overclocked to higher frequencies. This must be the consequence of the customized PCB or a higher power draw of the cooler’s fans. The configuration with two GTX 770s (the Palit plus the Zotac working at the same clock rates) needs 204 watts more than the configuration with only one such card and 73 watts more than the configuration with a dual-processor GeForce GTX 690. Now let’s see which one delivers higher performance.

Testbed Configuration and Testing Methodology

All participating graphics cards were tested in a system with the following configuration:

Since both GeForce GTX 770 graphics cards in the 2-Way SLI configuration worked at a 100 MHz higher GPU frequency than the nominal setting and the video memory worked at 200 MHz higher frequency than the nominal setting, we added 100 MHz to the GPU and 200 MHz to the memory speed on the dual-GPU GeForce GTX 690:

Once we evened out the video memory frequency on both: Palit and Zotac graphics cards, we could easily put together a cohesive 2-Way SLI system:

As for the single-card mode, we chose to benchmark Zotac product, since its video memory works faster than that on the Palit card.

We also included the reference Nvidia GeForce GTX 770 working at the nominal clock speeds for comparison purposes:


In order to lower the dependence of the graphics cards performance on the overall platform speed, I overclocked our 32 nm six-core CPU with the multiplier set at 48x, BCLK frequency set at 100 MHz and “Load-Line Calibration” enabled to 4.8 GHz. The processor Vcore was increased to 1.38 V in the mainboard BIOS:

Hyper-Threading technology was enabled. 16 GB of system DDR3 memory worked at 2.133 GHz frequency with 9-11-10-28 timings and 1.65V voltage.

The test session started on June 14, 2013. All tests were performed in Microsoft Windows 7 Ultimate x64 SP1 with all critical updates as of that date and the following drivers:

We tested the graphics cards performance in two resolutions: 1920x1080 and 2560x1440. The tests were performed in two image quality modes: “Quality+AF16x” – default texturing quality in the drivers with enabled 16x anisotropic filtering and “Quality+ AF16x+MSAA 4x(8x)” with enabled 16x anisotropic filtering and full screen 4x or 8x antialiasing, in those cases when the average fps rate remained high enough for comfortable gaming experience. We enabled anisotropic filtering and full-screen anti-aliasing from the game settings. If the corresponding options were missing, we changed these settings in the Control Panels of Catalyst and GeForce drivers. We also disabled Vsync there. There were no other changes in the driver settings.

The benchmarking suite used this time included two popular semi-synthetic benchmarks and 12 resource-consuming games of various genres:

If the game allowed recording the minimal fps readings, they were also added to the charts. We ran each game test or benchmark twice and took the best result for the diagrams, but only if the difference between them didn’t exceed 1%. If it did exceed 1%, we ran the tests at least one more time to achieve repeatability of results.


3DMark 2013

The factory-overclocked GeForce GTX 770 is expectedly faster than the reference card from Nvidia and somewhat slower when the latter is overclocked. The 2-way SLI configuration built out of two overclocked GTX 770s is 76% faster than the single such card and always ahead of the dual-processor GeForce GTX 690, which is overclocked, too.

Unigine Valley Bench

We can see the same standings here as in the previous test but the 2-way SLI configuration is more efficient, enjoying a larger advantage over the GeForce GTX 690.

Metro 2033: The Last Refuge

The SLI tandem of GeForce GTX 770s performs well in this game, being 91% faster than the single card and having no problems in terms of bottom speed. It is easily ahead of the dual-processor GeForce GTX 690.

Total War: SHOGUN 2 – Fall of the Samurai

The 2-way GeForce GTX 770 SLI configuration is good in Total War: SHOGUN 2 – Fall of the Samurai, too, especially when we turn on antialiasing (+94% compared to the speed of the single card). We don’t see any problems with bottom speed which can often be observed with multi-GPU configurations. The GeForce GTX 690 is slower than the SLI tandem, which, incidentally, costs less. The standings of the single cards won’t change in the remaining tests.

Battlefield 3

Excepting the CPU-dependent settings at 1920x1080, we can see the same standings in Battlefield 3:


Sniper Elite V2 Benchmark

The 2-way GeForce GTX 770 SLI configuration enjoys its largest advantage over the GeForce GTX 690 in this test session: 17 to 26%. On the other hand, we don't see such a large difference in terms of bottom speeds. The bottom speed of the SLI tandem is only comparable to that of the single-processor GeForce GTX 770 cards.

Sleeping Dogs

Sleeping Dogs is a CPU-dependent application too, so we can only evaluate the efficiency of the SLI tandem when we turn on antialiasing. In that case, the two GeForce GTX 770s are 87 to 97% ahead of the single GTX 770 and faster than the GeForce GTX 690.

Hitman: Absolution

The Hitman: Absolution benchmark seems to be even more limited by the overall performance of the platform, so every graphics card produces the same result at 1920x1080 without antialiasing.

But when we turn on 8x MSAA, we can see the second GeForce GTX 770 add 74-81% to the speed of the first one in the SLI tandem, so the latter is slightly ahead of the overclocked GeForce GTX 690.

Crysis 3

Crysis 3 is yet another game where 2-way SLI works perfectly. The SLI tandem is 86 to 90% ahead of the single card, has no problems with bottom speed, and easily beats the more expensive dual-processor GeForce GTX 690.

Tomb Raider (2013)

In the new Tomb Raider the 2-way SLI tandem boasts its highest efficiency in this test session – up to 100%! Considering that the bottom speed grows up, too, the two GeForce GTX 770s show exemplary performance here. They also have a clear advantage over the GeForce GTX 690 in this game.

BioShock Infinite

The SLI efficiency is lower in this game at 80%.

It’s a good result nonetheless. The low bottom speed of the SLI tandem has nothing to do with the SLI technology because the single-processor cards have the same problem.

Metro: Last Light

With Advanced PhysX turned on:

And with Advanced PhysX turned off:

In both cases the standings are the same. The SLI technology is expectedly more efficient at high loads (i.e. with enabled Advanced PhysX). The GeForce GTX 690 is always a little slower than the two GeForce GTX 770s.


GRID 2 is the only game on our list where the 2-way SLI tandem built out of GeForce GTX 770s is not very efficient. It is only 15 to 31% faster than the single GTX 770. The dual-processor GeForce GTX 690 isn’t any better. Hopefully, driver updates may bring some improvements in the future.

Company of Heroes 2

Although newer than GRID 2, Company of Heroes 2 responds well to our enabling SLI mode at 2560x1440 pixels with antialiasing. The performance boost is 75-81% then, but no higher than 50% at the lower settings.

Here’s a table with full test results, so we can move on to our summary diagrams.


Performance Summary Diagrams

First of all, let’s check out the difference between the faster of the two GeForce GTX 770s we’ve discussed today and the reference GeForce GTX 770.

The Zotac is an average 5-6% ahead of the reference variant thanks to the pre-overclocked GPU and memory. That’s good, especially as the original card doesn’t cost much more but features an improved PCB and high-efficiency cooler.

Now let’s see how efficient the SLI technology is when applied to two overclocked GeForce GTX 770s as compared to a single GTX 770 working at the same clock rates.

The SLI tandem isn't always perfect. For example, the performance growth in the new GRID 2 is very small (although Nvidia promises to improve it in new drivers). On the other hand, the SLI configuration can be up to 100% efficient in heavy games. The average performance growth across all the games with the antialiasing settings is 79 to 82%. Considering that the GeForce GTX 770 is new, we can expect it to perform better in SLI configuration as the drivers get more optimized.

And now let’s compare the SLI tandem built out of two overclocked GTX 770s (from Palit and Zotac) with the dual-processor GeForce GTX 690 which is overclocked to the same frequencies (+100 MHz for the GPU and +200 MHz for the graphics memory):

It is the GeForce GTX 770 tandem that wins most of the tests, only losing to the dual-processor card in GRID 2 and in one mode of Hitman: Absolution. The 2-way GeForce GTX 770 SLI configuration is faster than the GeForce GTX 690 by an average 5-8% at 1920x1080 and by an average 7-8% at 2560x1440 across all the games. Considering the lower cost of the SLI tandem, it is undoubtedly preferable to the GeForce GTX 690.


The two original GeForce GTX 770 graphics cards we’ve discussed today have quite a lot of things in common. They are similar in GPU frequencies and ASIC quality as well as in temperature, which means that their coolers are comparable in performance. Although the Zotac’s cooler is quieter, we can’t really call either of them quiet in 3D applications. As for differences, the Palit GeForce GTX 770 JetStream features an original PCB with an 8-phase GPU power system and check points for measuring voltages. It has higher overclocking potential, too. The Zotac GeForce GTX 770 AMP! Edition also features an improved PCB, yet it is overall simpler than the Palit's. The Zotac is more compact, has more accessories and comes with an extended 5-year warranty, though. In any case, we recommend our readers to wait for more reviews of original GeForce GTX 770s and only then make up their mind as to what exactly variant to buy.

As for our tests of the 2-way SLI configuration built out of two GTX 770s, we are quite satisfied with the outcome. It only failed in one game, namely GRID 2, but the latter is a new title, so this problem is likely to be corrected with driver updates and game patches. In the other cases, the GeForce GTX 770 tandem ensures a performance boost of 80 to 100%, beating the dual-processor GeForce GTX 690, which costs $1000 even now, a year after its release. That’s about $100 more than the cost of the two original GeForce GTX 770s. Savvy?