ASUS GTX 660 DirectCU II TOP Reviewccokeman -
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Testing of the ASUS GTX 660 DIrectCU II TOP will consist of running it and comparison cards through the OverclockersClub.com suite of games and synthetic benchmarks. This will test the performance against many popular competitors. Comparisons will be made to cards of a range of capabilities to show where each card falls on the performance ladder. The games used are some of today's newest and most popular titles, which should be able to provide an idea of how the cards perform relative to each other.
The system specifications will remain the same throughout the testing. No adjustment will be made to the respective control panels during the testing, with the exception of the 3DMark 11 testing, where PhysX will be disabled in the NVIDIA Control Panel, if applicable. I will first test the cards at stock speeds, and then overclocked to see the effects of an increase in clock speed. The cards will be placed in order from highest to lowest performance in each graph to show where they fall by comparison. The latest press release driver will be used in testing of the GTX 660, with the 660Ti tested with the release driver; AMD will be using Catalyst 12.6 drivers.
- Processors: Core i7 2600K @ 4.4 GHz 100 x 44
- CPU Cooling: Corsair Hydro Series H100
- Motherboard: Gigabyte Z68AP-D3
- Memory: Mushkin 993997 9-11-10-28 1866Mhz
- Video Card: ASUS GTX 660 DirectCUII TOP
- Power Supply: Corsair AX1200
- Hard Drive: Corsair Force GT 240GB
- Optical Drive: Lite-On Blu-Ray
- Case: Corsair Obsidian 650D
- OS: Windows 7 Professional 64-bit
Comparison Video Cards:
- ASUS GTX 660 DirectCU II TOP— Core 1206MHz, Memory 1635MHz
Overclocking this ASUS GTX 660 DIrectCU II was accomplished using ASUS' latest version of its GPU Tweak (Version 126.96.36.199) utility. When Kepler-based cards first launched there were concerns that overclocking would be limited due to how the onboard monitoring would down clock the card to keep within the power and thermal limits of the GPU. In fact there was just another wrinkle added to the process. Manage the thermals and only adjust voltage enough to reach the next clock speed plateau and all is good. If the power draw gets too high the symptoms will be that gaming performance or benchmarks will be drastically reduced from the expectations.
Starting out on this card I increased the power limit to its maximum level of 110%, bumped the fan speed to 100% and started bumping up the boost clock and running the card through some preliminary stress testing to find the limit on the core. I kept boosting and testing and bumping the core voltage in small steps until I reached a level where voltage would not fix the stability issues. I then followed the same process for the memory without the voltage increases until the game tests would fail. To that end it took 1100mv to reach the 1206MHz boost clock on the core and 1634MHz (6538MHz Effective) clock on the memory. The boost speed may not seem all that impressive but consider that it would go between the 1220 to 1233MHz range in just about every game with the card under the 110% power envelope. All told that is a +69MHz boost over the already impressive 1137MHz factory boost clock and 135MHz higher than the factory memory clock. Free performance at its finest. By boosting the fan speed to 100% the card never saw the high side of 59 °C in my testing. At 64 °C the stock cooling performance is good but it gets better as expected with increased fan speed. Now normally with fan speed comes noise, but not so with this implementation of the DCU II design. Much like its cousin the GTX 660Ti DCU II TOP, I was able to close up the chassis and eliminate the noise form the card with the cooling solution for the CPU being the loudest thing in the case.
ASUS' GPU Tweak utility has been revamped with features that include monitoring and tweaking, overclocking range enhancements to push the limits higher, a video recording option so that there is no need to spend money on FRAPS (that's money in your pocket if you use the feature), built-in GPU-Z reporting, and a pair of widgets. Overall it was easy to use and navigate through while testing out the functionality. Once you find you way around its a breeze. With the proliferation of gamers recording their gaming exploits and posting the content online it is all added value when you look at the cost concerns. Overall I was quite happy with the tools and how well this card overclocked.
Maximum Clock Speeds:
Testing for the maximum clock speed consists of looping Unigine 3.0 for 30 minutes each to see where the clock speeds fail when pushed. If the clock speed adjustment fails, then the clock speeds are adjusted and the test is rerun until each card passes the testing.
- Gaming Tests:
- Metro 2033
- Batman: Arkham City
- Battlefield 3
- Sid Meier's Civilization V
- Unigine Heaven Benchmark 3.0
- DiRT 3
- Mafia II
- 3DMark 11
- Power Consumption