|EVGA GeForce GTX 660 2GB SuperClocked|
|Reviews - Featured Reviews: Video Cards|
|Written by Olin Coles|
|Thursday, 13 September 2012|
Page 13 of 14
NVIDIA GPU Boost
Like the CPU found inside most modern desktop computer systems, the GPU inside a video card almost never reaches 100% usage. In fact, the CPU and GPU rarely use more than 10% of their available power, yet consume energy regardless of how much is actually needed. NVIDIA has recognized this, and followed suite with CPU manufacturers to offer variable clock speeds and power consumption. NVIDIA GPU Boost is a combination of dedicated hardware circuitry that continually monitors GPU power consumption along with software technology that works in the background. NVIDIA GPU Boost enables the GeForce GTX 660 video card to dynamically adjust power and clock speeds based on real-time application demands, automatically tweaking these settings several times per second. In some of the more demanding video games and applications there may occasionally be a time when the GPU is being fully utilized, which is when NVIDIA GPU Boost increases clock frequency to deliver improved graphics performance and higher image quality.
GPU Boost clock manipulates the top-end speed for the video card, which is controlled by hardware and software demands. The GPU Boost speed is not the same as the base core clock speed, which is not able to be adjusted as it has been with previous graphics products. GPU Boost works together with the Power Target ratio to determine how often or how high an overclocked 'boost' is established.
NVIDIA GPU Boost is not some marketing gimmick, it's a way for manufacturer's to ensure their product performs well on demand while conserving power whenever it sits idle. GPU Boost also complicates how enthusiasts define their clock speed. There's the core speed, which is a constant clock speed that never changes, and then there's the ever-changing Boost speed. Furthermore, the maximum GPU Boost speed is a target clock range the video card will attempt to operate at if it can maintain the defined power profile.
EVGA Precision X Overclocking Utility
EVGA offers a free software utility to overclocking enthusiasts named Precision X. EVGA Precision X is completely free software, and works with almost every video card on the market regardless of manufacturer. Register and download the utility from here: http://www.evga.com/precision/
This tool can be used to squeeze additional performance from one or more video cards by tweaking GPU and memory clock speeds within defined ranges based on the product. Unlike previous versions of NVIDIA GeForce video cards, the 600-series contain specific overclock ranges that ensure software tools do not adjust outside of safe parameters. These parameters vary between products and are set by the hardware's firmware programming, so not all products of the same model will share the same available range of settings. Voltage can be adjusted using the and power target setting, which helps to unlock greater GPU speeds.
EVGA Precision X is also useful for fine-tuning the cooling fan power profile as well as the temperature response curve. The graphics card uses an auto-tuned fan profile by default, although experienced users may manually tune their fan speed using the sliding fan-power scale to suit their cooling needs. Most GeForce GTX 600-series video cards already operate quietly even at 100% power, but it's better to use a purpose driven profile that reduces noise whenever possible. For this purpose, EVGA Precision enables a feature where users may define their own custom fan power scale with transition points.
The EVGA Precision X utility also allows hardware enthusiasts to monitor various aspects of their computer components, and can be customized to show metrics for every measurable aspect of the graphics card. Once the desired settings have been tested stable, EVGA Precision X can store up to ten custom profiles using buttons 1, 2, 3, etc. Some features such as Frame Rate Target help energy-conscious users conserve power while playing video games or working on the computer.
EVGA GTX 660 SC Overclocking
Because the EVGA GeForce GTX 660 SuperClocked comes from the factory with a substantial overclock, it's difficult to imagine having much overclocking headroom out of a GPU that's already been stretched well past the reference speeds. Using the retail kit 02G-P4-2662-KR for testing, I was able to achieve an additional 79MHz to the already-high GPU core clock. This raised the GPU Boost target, and was good for a few more FPS. Here are the results:
*Please note that the actual NVIDIA GPU Boost clock speed will vary, depending on system conditions and application demands. Typical GPU Boost speed shown.
Overclocking Summary: At reference speeds (980/1033*MHz) the GeForce GTX 660 performs well, but when giving a modest factory overclock the EVGA GTX 660 SC really matches up nicely to the more-expensive GTX 660 Ti (see chart above). For the most part, there was an average 1-FPS difference between reference clock speeds, the EVGA GTX 660 SC, and the 660 SC with maximum stable overclock. Every extra frame translates into an advantage over your enemy.