Chinese news outlet Zhuanlan (opens in new tab) has tested two of AMD's new Rembrandt Zen3+ mobile CPUs, with one of those chips being the new mid-range Ryzen 5 6600H with Radeon 660M graphics. According to the outlet's benchmark results, performance is impressively good, with the Radeon 660M usually outperforming Intel's highest-end graphics options in its Alder Lake mobile CPUs.
The Ryzen 5 6600H is part of AMD's new Zen3+ product stack, codename Rembrandt. The new microarchitecture upgrade brings excellent efficiency improvements to the Ryzen architecture, with 50 additional features added to Zen3+ to improve the power consumption of the entire SoC. Unfortunately, as a result, performance has not been improved that much -- despite the transition to TSMC's 6nm process.
However, this isn't the case for AMD's new graphics engine. AMD has finally made the jump to RDNA2 for its latest series of integrated GPUs, which pack some severe upgrades over AMD's previous Vega architecture, found in its prior IGPs. Clock speeds have increased by 300 MHz, and memory bandwidth has improved by 50% -- thanks to LPDDR5X, and the IGP's execution engine is now 50% larger. These are just some of the upgrades found in Rembrandt's new IGPs.
The Ryzen 5 6600H (opens in new tab) includes six cores and 12 threads, with a peak boost of 4.5 GHz and a default TDP of 45W. For graphics, the 6600H comes with the new Radeon 660M with six RDNA2 cores and a peak boost of 1.9 GHz. For comparison, AMD's flagship iGPU is the Radeon 680M which features double the core count and a maximum boost clock of 2.4 GHz.
Despite having just six GPU cores, the Radeon 660M shows competitive results in Zhuanlan's suite of game benchmarks, including League of Legends, CS:GO, Dota 2, Shadow of the Tomb Raider, Gears 5, and more. In addition, the Radeon 660M outperformed the Core i7-12700H with its 96 EU Iris Xe graphics engine -- the highest available graphics engine in Intel's mobile lineup.
However, performance is not entirely in favor of AMD. There were a couple of games where the Radeon 660M lost to Intel's Iris Xe iGP flagship, particularly in Apex Legends, F1 2018, Narka: Bladepoint, A Total War Saga, Troy, and Gears Tactics.
But for the most part, performance between the Radeon 660M and Iris Xe iGP was identical primarily, with just a few frames per second difference in most of the games tested. The only outliers were League of Legends, CS:GO, Assassin's Creed Odyssey, and Metro Exodus, which saw significant performance differences between the two iGPs. Of course, this can result from many things, including graphics drivers, core architectures, and power limits.
In further testing, Zhuanlan also evaluated the Ryzen 5 6600H's gaming capabilities under a range of power targets, including 25W, 42W, and 54W. Surprisingly, the benchmarks show gaming performance to be incredibly similar between all three power targets -- especially between the 42W and 54W results. The only outliers include League of Legends, Dota 2, and CS:GO, where performance severely drops off with the 25W limit.
The results show us that performance and efficiency peak at the Ryzen 5 6600H's default 42-45W power limit, and anything beyond that won't yield any beneficial gains when it comes to gaming.
Performance at 25W showed favorable results but was consistently below that of the 42W data. With some outliers showing severe performance drop off with the 25W limit. The Ryzen 5 6600H can perform well at 25W but can be prone to performance drop-off in specific workloads due to the shallow power target.
Overall, it appears AMD's new mid-range RDNA2 integrated graphics engine is a huge success and is a massive upgrade over the company's previous Vega graphics. In general, the Radeon 660M can slightly outperform Intel's top-of-the-line 96EU Iris Xe graphics featured in its Alder Lake CPUs. However, a significant achievement considering the 660M is AMD's mid-range iGP and doesn't even count AMD flagship Radeon 680M, which boasts twice the core count of the 660M.