Thu May 03, 2012 5:13 am
The new GeForce GTX 690 is NVIDIA's flagship graphics card. Powered by two Kepler GPUs, it’s both a record setter in 3D performance and incredibly power efficient. In fact, the GeForce GTX 690’s performance is almost identical to a pair of GeForce GTX 680s in SLI, but with significantly reduced power and noise.
The card's front plate is composed of two different materials. The exterior frame is made of cast aluminum with trivalent chromium plating, giving the board a durable, matte finish. The central fan housing is created from injection molded magnesium alloy. Magnesium alloys are used throughout the automotive and aerospace industry (including the engines of the Bugatti Veyron and F-22 Raptor) for their light weight, heat dissipation, and acoustic dampening properties. To create the intricate geometries required for the fan housing, we used a form of injection molding called thixomolding, in which liquid magnesium alloy is injected into a mold. This allows us to create fine geometries and a tight, perfectly coupled fit.
The GeForce GTX 690 is cooled via a pair of custom vapor chamber heat sinks. Unlike a traditional heat sink that uses conduction to move heat away from the GPU, a vapor chamber exploits the superior heat conducting characteristics of evaporation. Inside each vapor chamber is a small amount of purified water. As the GPU heats up, the water evaporates, carrying away heat in the process. Once the vapor reaches the top of the fin stack, it cools, condenses, and the process repeats itself. It's similar to a miniature form of water cooling but, because the liquid is entirely self contained, there's no need for tubing and no chance of leaks.
Kepler introduces hardware based frame rate metering, a technology that helps to minimize stuttering. In SLI mode, two GPUs share the workload by operating on successive frames; one GPU works on the current frame while the other GPU works on the next frame. But because the workload of each frame is different, the two GPUs will complete their frames at different times. Sending the frames to the monitor at varying intervals can result in perceived stuttering.
The GeForce GTX 690 features a metering mechanism (similar to a traffic meter for a freeway entrance) to regulate the flow of frames. By monitoring and smoothing out any disparities in how frames are issued to the monitor, frame rates feel smoother and more consistent.
Thu May 03, 2012 6:47 am
Thu May 03, 2012 9:09 am
Thu May 03, 2012 9:49 am