The g99 is stronger.
Compared with the Snapdragon 750g and Mediatek helio g99, the helio g99 has stronger overall performance. Released in May, the Mediatek helio g99 is built on TSMC's 6nm process and is equipped with two cores with a maximum frequency of 2.2GHz and six small cores with a frequency of 2GHz. The Qualcomm Snapdragon 750g processor, which was released by Qualcomm in September 2020, is based on the 8nm process and supports millimeter wave and sub-6GHz 5G. Frequencies up to 2.2GHz Small cores up to 1.8GHz. The Qualcomm Snapdragon 750g has a combined score of 49 in the CPU ladder ranking. The helio g99 ranks 48th on the Ladder. So the helio g99 is more powerful.