Our basic test hardware remains unchanged from the initial RX 6600 XT launch, except we're using the public 21.8.1 AMD drivers now. You can refer to the launch review for additional details, but we're using the same 13 game test suite. We've also enabled Trixx Boost and tested it at 1440p (2176x1224) as an extra data point. All of the games worked with Trixx Boost, though Dirt 5 required setting the desktop resolution to 2176x1224 and then running at "100% Native" scaling. We'll start with 1080p and then look at 1440p and 4K ultra results.
Pretty exciting stuff, right? At 1080p, the three RX 6600 XT cards all land within 0.5% of each other. The only real difference came from our Ryzen 9 5900X testing, where performance improved by about 2% overall, thanks mostly to a couple of the games that were really hitting CPU limits on the i9-9900K. There are a few cases where the Sapphire card came out slightly ahead, but mostly it's just margin of error differences. Let's move on.
The results at 1440p are again super close. This time, however, we've got Trixx Boost enabled. That improved performance by 24% on average, though a few games showed smaller or larger gains. Red Dead Redemption 2 was the outlier, with 52% higher performance. It's not clear if the card was running out of memory, or memory bandwidth (maybe both), but the lower resolution clearly helped a lot. Forza Horizon 4 showed the lowest gain of 13% because it was already hitting CPU limits. Everything else landed in the 20–32% range of improvement.
Trixx Boost is a nice extra feature, though it's possible to get similar results by manually creating a lower resolution as well — just without Radeon Image Sharpening doing the upscaling. We wouldn't necessarily spend a lot of extra money on a Sapphire card just to get access to Trixx Boost, but it's there if you happen to encounter a game that can't quite hit a steady 60 fps or more at your desired resolution.
Last, we have 4K, a resolution that's generally a better fit for faster GPUs — unless you don't mind 30 fps gaming. Forza Horizon 4 was the only game to clear 60 fps at 4K, and several games are right at the 30 fps threshold. We also saw the biggest difference between the ASRock and Sapphire cards at 4K: just 3%, in Red Dead Redemption 2. Despite its substantially larger cooler and third fan, plus a higher TDP and modest overclock, the Sapphire Pulse is only a hair slower than the ASRock Phantom Gaming.
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