AMD’s Radeon RX 6900 XT Liquid Cooled is one of the few reference models that come with an AIO cooler. Unfortunately, it’s limited to OEMs and SIs, and as such isn’t relevant to the DIY crowd. German outlet PC Games Hardware was able to get their hands on a unit via a pre-built PC, giving us an idea of how the GPU performs compared to its air-cooled variant.
There isn’t that much difference in the specs of the air-cooled and water-cooled models, but the latter boosts to nearly 2.5GHz (vs 2.25GHz for the reference model), allowing it to reach a higher performance target than the vanilla SKU:
At 1080p, the Radeon RX 6900 XT LC manages to beat the GeForce RTX 3090 by a margin of 3%, leveling with it at 1440p, and falling behind by 2% at UWQHD (3,440×1,440). Finally, at 4K, the RTX 3090 is 5% faster than the RX 6900 XT LC, an expected result considering the wider external bandwidth of the former.
In pure raster workloads, the RX 6900 XT is pretty much on par with the RTX 3090 (overall 4 resolution average), with the vanilla 6900 XT and the RTX 3080 Ti trailing by 6% and 3%, respectively:
In ray-traced games, the Radeon RX 6900 XT LC is 23% slower than the RTX 3090, 12% slower than the RTX 3080, and 6% faster than the vanilla RX 6900 XT on average across 10 games at four resolutions.
Overall, the RX 6900 XT LC provides a boost of just 6% over the reference variant, the same as most AIB overclocked models. This is due to the fact that AMD’s Navi GPUs are inherently poor overclockers, and don’t gain much even with hefty overclocks.