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System Builder Marathon, Q1 2014: The $750 Gaming PC

Improving High-Res Gaming By Overclocking Graphics

Intel's Core i3 can't be overclocked at all, and I didn't bother trying to eke out gains from the system memory. Rather, I focused all of my tuning efforts where they mattered most: extending the high-resolution gaming capabilities of Zotac's GeForce GTX 770 graphics card through aggressive overclocking.

Right out of the box, the graphics card ran coolly and quietly, with in-game GPU Boost frequencies pinned at 1150 MHz under heavy load. In CPU-limited workloads, clock rate dropped as low as 719 MHz at 0.9 V. That's normal behavior with GPU Boost-enabled hardware, as power-saving features kick in to save power in lighter tasks.

Nvidia's drivers are set to "Adaptive" Power Management Mode by default. While overclocking, however, I changed that to “Prefer Maximum Performance”, which prevents 3D clocks from dipping below the GPU's base value. Since neither the CPU nor the memory are overclocked, today's story gives us the bonus angle of benchmarking the effectiveness of Nvidia's efficiency concession, and see if it has any side effects. You can see slight variations in our charts using CPU-limited quality settings. In short, though, the driver option didn't make a bit of difference. At least in this configuration, the technology works as it should, paring back power consumption and heat without adversely affecting performance.

I had ambitious hopes to hit a 1300 MHz GPU Boost clock rate with this GeForce GTX 770, but ran into instability at 1267 MHz using 1.2 V. Unwilling to give up, I switched to the latest beta build of MSI's Afterburner software, which unlocked a 12 mV bump. The GPU then passed my initial stability testing at 1306 MHz.

The GDDR5 probably had more headroom, but I stopped at a stable 7806 MT/s data rate. To ensure extended stability, I backed both frequency settings down a bit, yielding a 1283 MHz GPU Boost clock rate and 7610 MT/s memory.