https://wccftech.com/amd-ryzen-9-4900u-flagship-15w-renoir-cpu-spotted-8-cores-faster-vega-gpu/

AMD's Flagship Ryzen 4000 'Renoir' CPU has been spotted, the Ryzen 9 4900U, which will feature faster specifications than the Ryzen 7 4800U. While both processors feature the same core config, it's the Ryzen 9 4900U which has the highest clocks of the two offerings and will be embedded in more powerful laptop designs, even if it is a 15W chip.

So far, AMD has officially announced the Ryzen 7 4800U as the fastest 15W Renoir chip but we had seen systems from various manufacturers which listed the Ryzen 9 4900U. The CPU has now been spotted in various online databases by TUM_APISAK, mainly 3DMark and UserBenchmark. It looks like AMD Ryzen 9 4900U, like the Ryzen 9 4900H, would keep the same core config as the Ryzen 7 SKU but take it up a notch by boosting the clock speeds in a higher binned package.