AMD Ryzen 9 7940HS analysis – Zen4 Phoenix is ideally as efficient as Apple

We had to wait quite a while for AMD’s Pheonix CPUs and after the impressive introduction of the Ryzen 9 7945HX a few weeks ago, our expectations of the new 4 nm chips with the codename Pheonix were obviously extremely high. After thoroughly testing the new Ryzen 9 7940HS, the results are a little sobering in total.

Compared to Intel, who have relied on a hybrid architecture since last year, AMD continue to use 8 full Zen4 cores. Single-core performance could also be increased by the higher Turbo Boost of 5.2 GHz and is now on par with last year’s H-series processors from Intel. However, AMD also has the problem that this performance increase comes with increased consumption, which is why its single-core efficiency is worse than last year’s old Zen3+ chips despite its higher performance.

AMD’s new Zen4 Pheonix processor features better performance and it can keep up with Intel in multi-core use – who use considerably more power. Its single-core performance is also better, but its single-core efficiency has sunk. It makes the most sense to run the new HS Zen4 chips at 35-55 watts, which gives laptop manufacturers more room to play with in terms of dedicated GPUs. 

Its multi-core performance is about 30% more compared to last year’s Ryzen 9 6900HS and its efficiency is also better, which is also the case in comparison to Intel processors. However, we can clearly see that its efficiency drops significantly at high power limits of more than 55 watts. The sweet spot for the new HS processors is 35-55 watts and at 35 and 45 watts, respectively, the new Zen4 chip comes within the range of Apple’s M2 chips (M2 Pro & M2 Max). This is definitely good news for the upcoming Zen4 Phoenix U-series CPUs (15-28 watts). In addition, laptop manufacturers have much more leeway for the dedicated graphics card when using the HS CPUs in compact devices, whereas Intel chips require more power for comparable performance.

However, its idle power consumption has increased slightly and here, the Intel chips also end up being more efficient. Then there is of course the new iGPU Radeon 780M, which we will take a closer look at in a separate article. However, you should not have too high expectations here…