At the foundation, both the Gainward Phoenix-S and the Gigabyte WindForce OC SFF are built on identical silicon: the same 8960 shading units, 280 TMUs, 96 ROPs, and 1750 MHz memory speed. This means their theoretical performance ceiling is governed by the same GPU die, and any difference between them comes down entirely to how aggressively each board partner has tuned the boost behavior.
That tuning is where the WindForce OC SFF pulls ahead. While both cards share the same 2295 MHz base clock, the Gigabyte reaches a 2497 MHz GPU turbo versus the Gainward's 2452 MHz — a 45 MHz advantage that cascades into every derived metric. Its floating-point throughput of 44.75 TFLOPS edges out the Phoenix-S's 43.94 TFLOPS, and its texture rate of 699.2 GTexels/s versus 686.6 GTexels/s means it can process geometry and shading slightly faster in complex scenes. In practice, the gap is roughly 1.8% — imperceptible in most gaming scenarios, but real and consistent.
The verdict for this group: the Gigabyte WindForce OC SFF holds a narrow but clear performance edge, driven purely by its higher factory boost clock. Both cards support Double Precision Floating Point, so neither has a compute workload advantage over the other. For users who will run both cards at stock settings, the WindForce OC SFF is the marginally faster card on paper — though the real-world gap is slim enough that thermal behavior and sustained clock maintenance will matter more in extended workloads.