GeForce Go 7900 GTX vs. GeForce Go 7900 GS: Mobile GPU Battle
How We're Testing
This is the first time we're taking an indepth look at evaluating a mobile GPU, so we can't approach it the same way as your typical desktop adapter. From a mobile perspective there are three important criterias to evaluate: performance, heat, and power consumption. Since a laptop often runs without a connection to an outlet, power consumption and the GPU's ability to adapt to different work loads is very important.
Testing Power Consumption and Power Conservation
PowerMizer 6.0 is a unique hardware and software power management technology on the Go 7900 GPUs that turns off parts of the processor when those parts are not in use to conserve power. PowerMizer also throttles operating voltages and frequencies to adapt to the workload so that the GPU only uses as much power and bandwidth as needed. Finally, the software driver allows the user to select how aggressive power savings are executed by the hardware.
When NVIDIA released the GeForce Go 7900, the PowerMizer power management feature interested me the most. For a laptop user who is unplugged, power conservation is a big concern but unfortunately NVIDIA's press material did not give much information about how PowerMizer affects real-world applications. In this article we will attempt to test some PowerMizer features as we measure the power consumed from the wall outlet at all different performance levels.
It will be interesting to see how the GeForce Go 7900 GTX and Go 7900 GS scales in performance as settings are changed from Performance to Power Savings.
Testing Thermal Properties
Since PowerMizer controls what parts of the GPU is used and how quickly it performs, we will measure the temperature of the GPU as it performs its duties. We use a temperature probe taped to the heatpipe just above the GPU and measure the results.
To test the GeForce Go 7900 GTX and Go 7900 GS, we have two identically configured Dell XPS M1710 gaming laptops. Same RAM, CPU, etc. The only difference is that one laptop has a GeForce Go 7900 GTX and the other has a Go 7900 GS. To find out the details of this wicked Dell gaming laptop, be sure to check out our review here.
Well, there's another difference. One laptop is red and the other is black, but we all know that the colour of a laptop doesn't make it go faster, right? RIGHT?
The following table summarizes our hardware configuration.
Dell M1710 Laptop
Intel T2600 Core Duo 2.16GHz (667 MHz bus)
2x1024MB DDR2 (5-5-5-13) - 667MHz
Hitachi 100GB 7200 RPM SATA
SigmaTel STAC9200 HD Audio
NVIDIA GeForce Go 7900 GS 256MB ()
Two Dell XPS M1710 monsters chewing through frames during testing.