by Sergey Lepilov
07/03/2012 | 08:41 AM
Graphics cards from Zotac International (MCO) Ltd. are yet less widespread than products of such giants as ASUS, Gigabyte, Sapphire and MSI. However, we've recently had a chance to make sure that they too are worth considering if you're shopping for a top-performance card because they offer a number of benefits compared to both reference solutions and original products from other brands.
Therefore we continue with our exploration of Zotac's model range and want to take a look at the GeForce GTX 680 2GB AMP! Edition (ZT-60302-10P) model which claims to be the fastest serially manufactured GTX 680. And it does have reasons for that claim!
The technical specifications of the Zotac GeForce GTX 680 AMP! Edition graphics card are summed up in the following table side by side with those of a reference Nvidia GeForce GTX 680 and theoretically fastest GTX 680 card from Asus (the differences are marked with bold font):
The graphics card is shipped in a large cardboard box. On its front you can see the name of the manufacturer, the product’s model name, a list of supported technologies and a sticker that lists the bundled games.
You can find a description of Nvidia's technologies and a brief list of the included accessories on the back of the box. Inside, there is another cardboard box with a soft foam-rubber tray with compartments for the graphics card and its accessories. The card is additionally protected by a plastic cover. The packaging seems reliable overall.
The Zotac GeForce GTX 680 2GB AMP! Edition comes with two power adapters, one DVI->D-Sub adapter, a CD with drivers, user manual and software tools, a few promo booklets, a coupon to download TrackMania 2 Canyon, and a special bundle with three games from the Assassin’s Creed series.
There are no video cables in the box, but that's hardly a problem. In fact, the accessories are gorgeous and we wish other manufacturers offered as many of them with their products.
The retail price of the Zotac GeForce GTX 680 AMP! Edition is $549, which is a mere $25-30 higher than the cheapest samples of the reference GTX 680. Like Zotac's GeForce GTX 670 AMP! Edition, the card is manufactured in China and comes with a 2-year warranty. Moreover, the warranty can be easily extended to as many as 5 years by simply registering the card at Zotac's official website.
The Zotac GeForce GTX 680 2GB AMP! Edition looks exactly like the GTX 670 AMP! Edition model from the same brand. The face side of the PCB is covered by the metallic casing of the cooling system with two bright-orange fans.
The sticking-out heat pipes increase the height of the card to 125 millimeters whereas its length and thickness are 266 and 56 millimeters, respectively, but the PCB alone is 255 millimeters long. The card is too thick to be used in a 2-way SLI configuration if there’s only one other slot between the graphics PCI Express slots on the mainboard.
The card is equipped with two dual-link DVI outputs, one HDMI version 1.4a, and one DisplayPort version 1.2. There’s also a vent grid in the mounting bracket to exhaust the hot air out of the system case.
Two MIO and two 6-pin power connectors can be found in their conventional locations.
The cooling system is attached to the PCB with only four screws around the GPU, so it is easy to remove. Then, we took off the heatsinks from the power system components and memory chips to have a good view of the PCB.
Contrary to our expectations, Zotac’s engineers use a reference PCB with 4+2-phase power system for this AMP! Edition product: 4 phases for the GPU and 2 for everything else.
That was okay for the Zotac GeForce GTX 670 AMP! Edition, but leaves us somewhat disappointed now because some other manufacturers reinforce the power supply of their GTX 680s by installing a fifth GPU power phase or even redesigning the entire PCB.
Since there are no differences from the reference PCB design here, the power system is managed by a PWM-controller RT8802A from Richtek Technology located on the reverse side of the PCB.
The 28nm GK104 chip was manufactured in Taiwan on the 15th week of 2012 (mid-April). It is revision A2, the only revision we can find on serially manufactured products.
The GPU has the standard GTX 680 configuration except for clock rate which is 1110 MHz in 3D mode, or 10.3% higher than the reference card’s. The boost clock rate is up to 1176 MHz high. In 2D mode the GPU clock rate is dropped to 324 MHz. That’s not the highest factory overclocking possible. For example, the ASUS GeForce GTX 680 DirectCU II TOP has a default GPU frequency of 1137 MHz (boosted to 1201 MHz) and is theoretically faster. However, the Zotac has its memory pre-overclocked by 10%, to 6608 MHz in 3D mode, which may give it an edge against the ASUS at high graphics loads.
Although pre-overclocked, the Zotac GeForce GTX 680 AMP! Edition has the same memory chips as most other top-end single-GPU Nvidia-based cards: Hynix H5GQ2H24MFR R0C.
Here is a summary of the graphics card’s specs reported by GPU-Z:
We’ve already seen this cooler with four 6mm copper heat pipes and a copper base in our review of the Zotac GeForce GTX 670 AMP! Edition.
We were not sure whether the pipes and copper base were soldered to each other, but they seem to be, judging by the dots that become visible where the base gets hot.
The two fans are attached right to the heatsink and covered with a metallic casing from above.
The heat pipes pierce the right part of the heatsink. The fins are soldered to the base, which is the only way for the heat to get to the left part of the heatsink.
The fins, soldered to the pipes too, are 0.3 millimeters thick and 2 millimeters apart from each other. There are small aluminum heatsinks with thermal pads mounted on the power components and memory chips.
Two 7-blade 92x12mm fans are set to blow at the heatsink.
Labeled MGT9212YB-W20, they are manufactured by Protechnic Electric.
Judging by the sticker, the peak power draw of each fan is 5.8 watts at 0.48 amperes. The speed is PWM-regulated from 1350 to 3600 RPM but the top speed is actually limited to 85% in the graphics card’s BIOS.
We checked out the card’s temperature while running Aliens vs. Predator (2010) in five cycles at the highest settings (2560x1440, with 16x anisotropic filtering and 4x antialiasing).
We used MSI Afterburner 2.2.2 and GPU-Z 0.6.2 as monitoring tools. This test was carried out with a closed system case at an ambient temperature of 25°C. We didn’t change the card’s default thermal interface. Let's see how efficient Zotac's exclusive cooler is on the top-end GTX 680:
Auto fan mode
Maximum fan speed
With the fans regulated automatically, the GPU temperature was as high as 78°C, the fans rotating at 2220 RPM (or 46% of their full speed). And if the speed is manually set at 3600 RPM (85%, which is the maximum set in the graphics card's BIOS), the GPU is 7°C cooler and has a temperature of 71°C at peak load. Considering that this is a pre-overclocked card whose GPU can occasionally work at 1189 MHz, the results are satisfactory, although the same cooler had done much better on our Zotac GeForce GTX 670 AMP! Edition.
We had some doubts about these results, though, so we replaced the default thermal interface with Arctic MX-4. We were astonished at the difference:
Auto fan mode
Maximum fan speed
The GPU temperature lowered by as much as 13°C in the automatic regulation mode, so the GPU was only 65°C hot and the fans slowed down from 2220 to 1950 RPM. At the maximum 3600 RPM, the temperature was 59°C or 12°C lower than with the default thermal interface. Well, we don’t want to blame the thermal interface alone. Perhaps the factory assembly of the cooler wasn’t perfect (one of the screws wasn’t tightened up, although the thermal grease imprint on the GPU seemed to be okay). Anyway, the fact is that we significantly increased the efficiency of Zotac's cooler by replacing the default thermal interface.
Then we measured the level of noise using an electronic noise-level meter CENTER-321 in a closed and quiet room about 20 sq. meters large. The noise-level meter was set on a tripod at a distance of 15 centimeters from the graphics card which was installed on an open testbed. The mainboard with the graphics card was placed at an edge of a desk on a foam-rubber tray.
The bottom limit of our noise-level meter is 29.8 dBA whereas the subjectively comfortable (not low, but comfortable) level of noise when measured from that distance is about 36 dBA. The speed of the graphics card’s fans was being adjusted by means of a controller that changed the supply voltage in steps of 0.5 V.
We’ve included the results of the reference Nvidia GeForce GTX 680 and the ASUS GeForce GTX 680 DirectCU II TOP into the next diagram for the sake of comparison (the ASUS card has a highly efficient and quiet cooler). Here are the results (the vertical dotted lines indicate the top speed of the fans in automatic regulation mode):
Unfortunately, the Zotac GeForce GTX 680 AMP! Edition isn't quiet. Yes, the original cooler from Zotac is quieter than the reference GeForce GTX 680 in the automatic fan regulation mode, but it is much worse than the one installed on the ASUS GeForce GTX 680 DirectCU II TOP, which seems to be the best cooler among all serially manufactured graphics cards.
We’d recommend Zotac not only to change their fan supplier because the fans rattle at low speed but also limit the bottom speed to 1000 rather than 1350 RPM. This would make the card quieter and even silent in 2D applications.
We always set the power limit to its maximum when benchmarking GeForce GTX 6xx series cards, especially in our overclocking tests. This limit is 132% with the Zotac GeForce GTX 680 AMP! Edition.
After some experimenting we managed to add 95 and 420 MHz to the card's default GPU and memory frequencies, respectively.
As a result, our Zotac GeForce GTX 680 AMP! Edition was stable at clock rates of 1206 MHz (+79 MHz in boost mode) and 7028 MHz.
That’s very good for a pre-overclocked graphics card, especially as Zotac's cooler kept the temperatures low even after our additional overclocking:
The GPU is only 69°C hot and the fans rotate at 2040 RPM.
We measured the power consumption of computer systems with different graphics cards using a multifunctional panel Zalman ZM-MFC3 which can report how much power a computer (the monitor not included) draws from a wall socket. There were two test modes: 2D (editing documents in Microsoft Word and web surfing) and 3D (the benchmark from Metro 2033: The Last Refuge at 2560x1440 with maximum settings). Here are the results:
Well, we already know how much power GeForce GTX 680 and Radeon HD 7970 cards need, so we don’t see anything particularly new here. Compared to the reference GTX 680, the system with the Zotac GeForce GTX 680 AMP! Edition consumes 15 watts more. When overclocked to 1206/7028 MHz, it needs an additional 14 watts. The system with the Radeon HD 7970 needs 70 watts more anyway. We can also add that a computer with any of these graphics cards would require a 550-watt PSU, which is the basic minimum for today's gaming platforms.
All participating graphic cards were tested in a system with the following configuration:
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 37x, BCLK frequency set at 125 MHz and “Load-Line Calibration” enabled to 4.625 GHz. The processor Vcore was increased to 1.46 V in the mainboard BIOS:
Hyper-Threading technology was enabled. 16 GB of system DDR3 memory worked at 2 GHz frequency with 9-10-10-28 timings and 1.65V voltage.
The test session started on June 26, 2012. All tests were performed in Microsoft Windows 7 Ultimate x64 SP1 with all critical updates as of that date and the following drivers:
The graphics cards were tested 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 4(8)x” with enabled 16x anisotropic filtering and full screen 4x or 8x antialiasing if the average framerate was 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.
Since we have already tested GeForce GTX 680 based graphics cards multiple times before, we decided to run less tests this time. Our list of games and applications used in this test session will include three semi-synthetic benchmarking suites and six most resource-demanding popular games:
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.
The numbers from semi-synthetic benchmarks and Aliens vs. Predator (2010) will be illustrated by screenshots with the results of the Zotac GeForce GTX 680 AMP! Edition at its default (left) and overclocked (right) frequencies.
The default Zotac GeForce GTX 680 AMP! Edition is 6% ahead of the reference GeForce GTX 680 without antialiasing and 9% ahead when antialiasing is turned on. It also outperforms its junior cousin Zotac GeForce GTX 670 AMP! Edition by a similar margin. The Radeon HD 7970 GHz Edition is much slower at the Performance settings but closes the gap at the Extreme settings thanks to its larger amount of onboard memory and wider memory bus.
The Zotac GeForce GTX 680 AMP! Edition is ahead in 3DMark 2012 both at its default and overclocked frequencies. It has no rivals today, actually, and enjoys an advantage of 8-9% over the reference GeForce GTX 680.
The Zotac GeForce GTX 680 AMP! Edition feels at ease in this demo, too, outperforming the reference GTX 680 by the same 9-10% and meeting no resistance from the AMD Radeon HD 7970 GHz Edition.
The Radeon goes ahead in Metro 2033: The Last Refuge, the Nvidia-based solutions competing with each other. The Zotac GeForce GTX 680 AMP! Edition is 9-10% ahead of its reference cousin.
The Radeon has an advantage in Aliens vs. Predator (2010). The Zotac GeForce GTX 680 AMP! Edition can only resist the Radeon HD 7970 GHz Edition when there's no antialiasing. When we turn 4x MSAA on, the Zotac can’t compete with the Radeon despite its good overclocking.
The GeForce 304.48 beta driver has brought the performance of the GeForce GTX 6xx series back to its previously high level in Total War: Shogun 2. Meanwhile, AMD’s Catalyst 12.7 beta doesn’t change anything in the Radeon HD 7970’s behavior here. That’s why the green team are as fast as the read one and even go ahead when antialiasing is turned on.
Crysis 2 and Battlefield 3 produce the same standings: the pre-overclocked GeForce GTX 680 from Zotac is about as fast as the Radeon HD 7970 GHz Edition.
The Radeon is superior in the newest game on our list. As for the GeForce series, the Zotac GTX 680 AMP! Edition is 8-9% ahead of the reference card from NVIDIA.
Cutting a long story short, the Zotac GeForce GTX 680 2GB AMP! Edition is one of the best original graphics cards with the GK104 Kepler processor. The increased GPU and memory clock rates make it 8-10% faster than the reference GTX 680 as well as the majority of original cards from other brands. The exclusive cooler, although not very quiet, ensures good protection against overheat, even if you dare overclock the card further. The attractive and robust packaging, numerous accessories, stylish exterior, cutting-edge Nvidia technologies and competitive pricing make this product the No.1 candidate for purchase among all GeForce GTX 680s.
We might criticize it for using the reference PCB but the latter fact didn’t prevent our sample from doing well in our overclocking tests whereas its long service life is promised by Zotac's extended 5-year warranty.