The CPU-usage benchmark shows us just how much of the load the SpursEngine is taking off of the CPU:
Only the dual-core Athlon II X2 utilizes more than 60% of its resources when the WinFast PxVC1100 card is handling encoding, while all of the quad-core CPUs have compute headroom to spare. Contrast this with the CPU-only encoding, where only the Core i7-920 processor is using less than 90% of its total processing capacity.
These are impressive numbers, suggesting that a PC using the SpursEngine could still be used for other tasks while encoding. This is not something that a CPU-only solution would comfortably allow. Truly, this is probably the largest real-world benefit of the WinFast PxVC1100.
We can see the performance and CPU usage benefits, but what about the power usage of the WinFast card?
The WinFast board hardly makes a dent in overall power consumption. Even though the SpursEngine is likely drawing at least 10W under load, consider that the CPU is drawing less power while the add-in board is shouldering the workload. The end result is a relatively flat power result, despite the dramatic performance increase.