Overclocking

To find the maximum overclock of our card we used a combination of ATITool's successor and our benchmarking suite.
The overclocks listed here were achieved with the default fan and voltage settings as defined in the VGA BIOS. Please note that every single sample overclocks differently, that's why our results here can only serve as a guideline for what you can expect from your card.



The overclocks of our card are 970 MHz core (1% overclock) and 1100 MHz Memory (5% overclock). Both overclocks are very disappointing but were to be expected since the default clocks are already quite high.

Unlike many other HD 4890 manufacturers Sapphire did not increase the GPU voltage too much to reach higher overclocks. So if you choose to go beyond the stock voltage of 1.4V you will easily reach 1000 MHz GPU clock.

I did a quick run at 1.5V to test this and reached spot on 1000 MHz.

Overclocked Performance

Using these clock frequencies we ran a quick test of Call of Duty 4 to evaluate the gains from overclocking.


The actual 3D performance gained from the "normal voltage" overclocking is 1.7%.

Temperatures

The temperatures reflect the perfect balance between fan noise and GPU temperature in my opinion. Around 80°C is perfectly safe for any graphics card.