I ran a series of tests on both graphics card to determine how they handled overclocking and the amount of heat generated while under stress. Overclocking was performed using EVGA's Precision Software. I began by incrementing the core and memory clocks in small amounts (the shader clock was linked to the core clock).
I stress tested the graphics cards using FurMark while temperatures were monitored with GPU-Z. I didn't attempt to determine the maximum clock speeds, but rather tried to find a reasonable overclock while maintaining a reasonable temperature. The table below shows the results.
I obtained a 75MHz overclock on the core and 200MHz (400MHz effective) overclock on the memory. This is a nice and modest overclock. Let's take a look at how the temperatures faired.
Naturally, the ambient and idle temperatures didn't change much. The maximum temperature increased by 7 degrees. This increase keeps the graphics card well within normal operating ranges. Next, I benchmarked Tom Clancy's HAWX again with the graphics card overclocked to determine any increase in performance.
Here we can see that overclocking the GeForce GT 240 helped it gain some ground on the GeForce 9800 GT and narrowed the performance gap. The overclock brought the graphics card close to the GeForce 9800 GT in terms of performance as each resolution gained approximately 5 FPS. This equates to a 10.6%, 12.5%, and 14.7% performance increase for the 1280x1024, 1680x1050, and 1920x1200 resolutions, respectively.
Lastly, I checked out the video encoding performance of the GeForce GT 240 and GeForce 9800 GT. For video encoding, I used the video encoding software badaboom. The table below provides the results for recoding tests (i.e. decoding, then encoding) a 100MB file at 720p.
Video Encoding Test
The GeForce 9800 GT was faster at encoding the video and outpaced the GeForce GT 240 due its greater number of stream processors. However, the GeForce GT 240 still put up an impressive time of seven and a half minutes for a 100MB file. This is more than a reasonable time for HTPC owners who want to re-encode files on their systems.