Gainward’s GT 520 SilentFX runs at reference GPU clocks – 810MHz. However, Gainward increased the memory clocks from reference 900MHz to 1070MHz. Nvidia did not want to intrude on the GT 430 but we’d still like to have seen a bit better performance by the GT 520.
Video processing and power consumption
Most users who want Nvidia?s GT 520 will use it for viewing HD movies, off of their own media servers or online, i.e. they'll utilize to the max solely for multimedia. Linux users on the other hand will prefer Nvidia to AMD due to the former's superior driver support. Relatively low consumption, passive cooling and enough juice for postprocessing effects are the pros for GT 520 because, as you've seen yourself, it's not quite tailored for gaming. The cheaper GT 430 on the other hand would be much better for this purpose.
Load Temp Gaming
GPUZ showed fan speed as well, although the GT 520 SilentFX is passively cooled.
Load Temp 1080p