Hello, Kirin 990 and Kirin 980 consume the same amount of power. They're all 7nm technology.
It can be seen from comparing 990 and 980. The 990 CPU and GPU architecture did not cross generations, still continued the Cortex A76 Mali G76, the cache capacity is unchanged, the CPU frequency has increased, and the GPU although the number of cores has increased, but the actual frequency has decreased.
According to Huawei's official data, the Kirin 990 claims to be 10% more single-core performance than the Snapdragon 855 CPU, and the multi-core performance exceeds 9%; The GPU performance is 6% better than the Snapdragon 855.