We've all seen lots of conflicting benchmarks that either confirm or disprove the real world functionality of the dual GPUs in FCPX. What makes this difficult is there are so many combinations of CPU & GPU that you can't actually determine if the speed gaps are because of the CPU or the GPU. For example, I've seen a lot of benchmarks that sometimes show a D300 beating a D500... but the reality is those benchmarks are also using different CPUs, so you can't tell if the D300 won simply because it was a single threaded program that runs better on a 4 core than an 8 core. So, to get a definitive answer, I came up with a very simple benchmark that takes a few minutes to run and it doesn't require downloading any programs or video content. If anyone is willing to run the test and post their CPU and GPU results, we can sort them by CPU so that the results show exactly what the advantages of each GPU are. The goal is to only compare: 4 core D300 vs 4 core D500 vs 4 core D700. 6 core D300 vs 6 core D500 vs 6 core D700. 8 core D300 vs 8 core D500 vs 8 core D700. 12 core D300 vs 12 core D500 vs 12 core D700. A home run would be to get the same test run on all three GPUs for at least one group of CPUs. For me, it doesn't matter which group (4, 6, 8, 12), but the real key is to get all three tests in the same class CPU. A GRAND SLAM would be to some day get all 12 combinations. Then we would know how much a real world application like FCPX scales with the various configurations. Obviously there is a sweet spot somewhere. ===== HERE'S MY TEST ===== In order to simulate a real world FCPX project, I decided to shoot for something longer than BruceX, which is only 6 seconds. Short benchmarks are skewed easily by Turbo Boost, so this one creates an 8 minute 1080p video. My test has 5 steps: 1. Create a 1920 x 1080p 30p project, and place "Pages" from the Generator on the timeline... then make the duration exactly 8 minutes, then time how long it takes to background render it. 2. Add the "Clouds" title to the start, change it's duration to 8 minutes too... and time the background render. 3. Add the "Romantic" filter to the "Pages" clip and time the background render. 4. Export a ProRes 422 master, then time it. 5. Compress it with Compressor using the "Apple Devices HD (Best Quality)" preset... then time it. ---- My FIRST RESULTS ---- Mac Pro 4 Core, D300 Step 1, "Pages". 1:49 Step 2, "Clouds" 2:28 Step 3, "Romantic" 2:44 Step 4, Render ProRes 422: 36 seconds Step 5, H.264 Compression: 6:25 Since the 4 core, D300 is the entry level, I would LOVE to see results from other configurations. A 4 core D500 or 4 Core D700 would truly answer a LOT of questions, because we could then rule out the CPU differences. I'm hoping we can pull off a real home run or two... all three GPUs for any CPU. Any takers?