Overclocking Intel's Core i5-3470 can't get any easier. I kept the company's power-saving features turned on and enabled the “Non K-series Overclocking” option in ASRock's firmware, exposing multiplier settings up to 40x.
Our Core i5-3470 didn’t need any extra voltage to run stably at 4 GHz with one or two of its cores active. Intel's baked-in limitations step frequency down to 3.9 GHz with three cores active and 3.8 GHz with the CPU under full load. That's not bad, though. We managed a 400 MHz boost in light loads and 600 MHz with all cores active in more heavily-threaded apps.
To help with heat as I overclocked, I disabled PWM fan control, running the CPU and case fans at full duty cycle. Pegged around 2000 RPM, they make so little noise that they're drowned out by the graphics card in gaming tests.
Satisfied with my elevated Core i5 clock rates, I set about tweaking the RAM. Team Vulcan's DDR3-1600 kit needed more than 1.55 V and returned minimal gains. So, I left the modules at their XMP timings and moved on to graphics.
Unfortunately, Gigabyte’s Radeon R9 280X was less cooperative than I expected. Its high factory frequencies delivered excellent stock performance. But with the GPU's voltage locked at 1.131 V under load, it was already running close to the practical limit. I only got another 20 MHz out of the chip before it became unstable. And pushing the card's memory didn't seem worthwhile either. Performance gains with 1600 MHz GDDR5 barely registered at all.
On the bright side, I didn't see any evidence of throttling under load. Even in taxing games, the Tahiti GPU ran at a constant 1100 MHz.
I settled on 1115 MHz core and 1600 MHz memory clock rates. Honestly though, if this card was in my own workstation, I'd leave it at Gigabyte's factory-overclocked settings. The payoff is just too small.