|ASUS GeForce GTX 660Ti DirectCU-II TOP|
|Reviews - Featured Reviews: Video Cards|
|Written by Olin Coles|
|Thursday, 16 August 2012|
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NVIDIA GPU Boost
Like the CPU found inside computer systems, the GPU found in video cards 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 Ti 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.
ASUS GPU Tweak Utility
In the past, software-based overclocking on ASUS video cards had been accomplished through the ASUS SmartDoctor software (and GamerOSD tool prior to that). Now all overclocking and status monitoring tasks are handled by ASUS GPU Tweak and Monitor software (illustrated below).
ASUS GPU Tweak (GPUTweak.exe) allows users to adjust a controlled range of GPU core and boost clock speeds, memory clock speed, cooling fan power, minimum GPU voltage, and maximum boost power target. Tuning controls are part of the GPU Tweak portion of the software, which users can compliment by adding the Monitor (Monitor.exe) tool which is displayed along the left side when is enabled.
The ASUS Monitor utility can be customized to show metrics for every measurable aspect of the graphics card, allowing the user to add/remove fields as they see fit. Additionally, ASUS Monitor can record data to a log file saved onto the computer system. In the illustration of Monitor below (left side), I've demonstrated how particular times can be hovered over to gather data from that period, or set multiple periods using right-click.
GPU Tweak Overclocking
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.
GPU Boost Clock manipulates the top-end speed for the video card, which is controlled by hardware and software demands (GPU Boost is discussed elsewhere in this article). 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.
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. The ASUS GTX660Ti DirectCU-II TOP model operates extremely quiet even at 100% power, but it's better to use a purpose driven profile that reduces noise if possible. For this purpose, ASUS GPU Tweak eneables a feature where users may define their own custom fan power scale with transition points.
Once the desired settings have been tested stable, the ASUS GPU Tweak can be used to store up to four custom profiles (using buttons 1, 2, 3, 4), or apply one of two pre-set profiles: Power Saving (button P) or Gaming (G).
660Ti DirectCU-II TOP Overclocking
Because the ASUS GeForce GTX 660Ti DirectCU-II TOP 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 144 MHz/157 MHz (Boost) past the reference speeds. To my surprise, I was able to achieve 1200 MHz (Boost) stable NO additional power or increase to power target. However, with a bump to minimum and target power settings there was room to bump the speeds to a 'mostly stable' 1210 MHz Boost.
*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: Upgrading performance from NVIDIA GeForce GTX 660 Ti reference speeds to ASUS GTX660Ti DirectCU-II TOP levels, nearly every game tested jumped 2-3 FPS thanks to the factory overclock. Pushing even farther to a 1200 MHz GPU Boost clock speed, we captured another 2-3 FPS over the TOP results at 1920x1080 resolution. Essentially, our maximum overclock resulted in 5-7 FPS beyond reference values and closed the gap between a stock GTX 660 Ti and GTX 670. Every extra frame translates into an advantage over your enemy.