at the right balance of frame buffer bandwidth required to keep the texture units
fully utilized and not starved for data.
General frame buffer efficiency has been improved for GeForce GTX 200 GPUs.
We reworked the critical paths in the frame buffer to allow higher speed memory
operation, up to 1.1 GHz GDDR3 stock speed. Memory bank access patterns and
caching algorithms have also been improved. Additional compression hardware in
GeForce GTX 200 GPUs effectively increase frame buffer bandwidth by permitting
more data to traverse the interface per unit time, enabling better performance at
higher resolutions.
Power Management Enhancements
GeForce GTX 200 GPUs include a more dynamic and flexible power management
architecture than past generation NVIDIA GPUs. Four different performance /
power modes are employed:
Idle/2D power mode (approx 25 W)
Blu-ray DVD playback mode (approx 35 W)
Full 3D performance mode (varies—worst case TDP 236 W)
HybridPower™ mode (effectively 0 W)
Using a HybridPower-capable nForce motherboard, such as those based on the
nForce 780a chipset, a GeForce GTX 200 GPU can be fully powered off when not
performing intensive graphics operations and graphics output can be handled by the
motherboard GPU (mGPU).
For 3D graphics-intensive applications, the NVIDIA driver can seamlessly switch
between the power modes based on utilization of the GPU. Each of the new
GeForce GTX 200 GPUs integrates utilization monitors (“digital watchdogs”) that
constantly check the amount of traffic occurring inside of the GPU. Based on the
level of utilization reported by these monitors, the GPU driver can dynamically set
the appropriate performance mode (i.e., a defined clock and voltage level) that
minimizes the power draw of the graphics card—all fully transparent to the end
user.
The GPU also has clock-gating circuitry, which effectively “shuts down” blocks of
the GPU which are not being used at a particular time (where time is measured in
milliseconds), further reducing power during periods of non-peak GPU utilization.
All this enables GeForce GTX 200 graphics cards to deliver idle power that is nearly
1/10th of its maximum power (approximately 25 W on GeForce GTX 280 GPUs).
This dynamic power range gives you incredible power efficiency across a full range
of applications (gaming, video playback, surfing the web, etc).
Many other areas of the GeForce GTX 200 GPU pipeline have been reworked to
improve performance and reduce various processing bottlenecks.
Additional Pipeline and Architecture Enhancements
Starting from the top of the GeForce GTX 200 GPUs, the front-end unit
communicates with the graphics driver running on the host system to accept
commands and data. The communication protocol and certain software classes have
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May, 2008 | TB-04044-001_v01
