Overclocking fared roughly the same for both graphics cards with 7900MHz effective memory for the GTX 950 and 8000MHz effective for the GTX 960, up from 7200MHz stock on both. Maximum boost clocks increased by 8.2% for the GTX 950 and 8.7% for the GTX 960.
These are par-for-the-course maximum overclocks for a GTX 950 and 960, suggesting to us there's been no speed-binning of chips here – not that it would be reasonable to expect that on such a budget-level GPU anyway. It is likely possible to go further with vBIOS or voltage mods, however, this would void your warranty and has a number of risks.
The aforementioned overclocks translated into an 8.3% boost in 3DMark performance for the PNY GTX 950 and a 9.1% boost for the GTX 960. In real terms there is very minimal overclocking headroom to be had, less than 10%, due to already high factory overclock
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