AMD Ryzen 9 PRO 7940HS vs AMD Ryzen 9 4900H vs AMD Ryzen 7 7840HS

AMD Ryzen 9 PRO 7940HS

The AMD Ryzen 9 PRO 7940HS is a fast high-end laptop processor of the Phoenix series. It offers 8 cores (octa core) based on the Zen 4 architecture that supports hyperthreading (16 threads). The cores clock from 4 (base) up to 5.2 GHz (single core boost). The processor includes 8 MB L2 cache and 16 MB L3 cache.

Compared to the consumer Ryzen 9 7940HS, the PRO models offer additional security, manageability, and reliability features designed for professional users and workstation environments.

The performance of the R9 PRO 7940HS should be slightly higher than the old top model Ryzen 9 6980HX (8 Zen 3 cores with up to 4.9 GHz) at 54W TDP and Ryzen 9 6980HS at 35W TDP. Compared to the higher end Dragon Range series, the 7940HS should be similar to the Ryzen 7 7745HX (also 8 Zen 4 cores, max 5.1 GHz, 55W tDP, 32 MB L3).

The chip integrates a modern and fasts RDNA 3 graphics card (iGPU) called Radeon 780M with 12 CUs and up to 2.8 GHz clock speed. Furthermore, the Phoenix series include a video engine with AV1 de- and encoding, a new Xilinx FPGA based XDNA AI accelerator (Ryzen AI) that should be faster than the AI engine in the Apple M2 SOC and a dual-channel DDR5-5600 / LPDDR5x-7500 memory controller (with ECC support). The connectivity features includes 2 possible USB 4 (40 Gbps) ports and 20 PCIe 4.0 lanes for a GPU and SSDs.

The Phoenix series uses a single monolithic design (unlike the chiplet design of the 7045HX series) and is manufactured in the modern 4nm process at TSMC. The TDP can be configured between 35 and 45 Watt.

AMD Ryzen 9 4900H

The AMD Ryzen 9 4900H is a mobile SoC for big laptops based on the Renoir architecture. At the time of announcement in March 2020 it is the fastest model of the 4000H series. The R9 4900H integrates all eight cores based on the Zen 2 microarchitecture. They are clocked at 3.3 (guaranteed base clock) to  4.4 GHz (Turbo) and support SMT / Hyperthreading (16 threads). The chip is manufactured in the modern 7 nm process at TSMC and partly thanks to it AMD advertises a 2x improved performance per Watt for the Renoir chips

According to our information, the Ryzen 9 4900H is only slightly faster than the Ryzen 7 4800H. The CPU is clocked 400 MHz (base +14%) to 200 MHz (boost +5%) higher, but the gains greatly depend on the cooling and TDP settings. Compared to Intel chips, the i9-9980HK top model should be comparable. That means the Ryzen 9 4900H should be able to handle all demanding tasks and gaming.

In addition to the eight CPU cores, the APU also integrates a Radeon RX Vega 8 integrated graphics card with 8 CUs. The dual channel memory controller supports DDR4-3200 and energy efficient LPDDR4-4266 RAM. Furthermore, 12 MB level 3 cache can be found on the chip. See our hub page on the Renoir Processors for more information.

The TDP of the APU is specified at 45 Watt (default). That means the chip is intended for big and relatively heavy laptops.

AMD Ryzen 7 7840HS

The Ryzen 7 7840HS is a powerful Phoenix family chip that saw the light of day in H1 2023. The processor features 8 cores (16 threads thanks to SMT support) running at 3.8 GHz. The highest Boost clock speed achievable is 5.1 GHz.

Not only does this APU has full might of the Zen 4 architecture at its disposal, it also comes with the new Ryzen AI technology that's set to make generative AI more ubiquitous than ever before. Last but not the least, the Radeon 780M serves as the integrated GPU.

Architecture & Features

Phoenix family chips are powered by the Zen 4 architecture, much like Dragon Range family chips are. The latter however lacks hardware AI workload acceleration capabilities that Phoenix has. Ryzen AI is coming after Intel's DL Boost and GNA technologies; time will tell if this move by AMD is a good idea.

Perhaps more importantly, Zen 4 introduces AVX512 support (which Zen 3 chips did not have) and, thanks to a plethora of other improvements including larger caches/registers/buffers across the board, is set to bring a double-digit IPC improvement.

Elsewhere, the 7840HS has 16 MB of L3 cache and a seriously fast RAM controller (up to LPDDR5x-7500 and up to DDR5-5600, ECC-enabled memory included). PCI-Express speeds are capped at 1.97 GB/s per lane which corresponds to the 4.0 spec.

This Ryzen 7 series chip is designed to run 64-bit Windows 11, 64-bit Windows 10 or Linux; please note that it isn't overclockable and neither is it user-replaceable. It gets soldered down for good instead (FP7, FP7r2, FP8 socket interfaces).

Performance

The average 7840HS in our database is in the same league as the Core i7-12700H, Core i7-12850HX, Core i9-12900H, Core i9-13900H and also the Ryzen 9 7940HS, as far as multi-thread benchmark scores are concerned. This is a very fast chip, as of Q3 2023.

Your mileage may vary depending on how high the CPU power limits are and how competent the cooling solution of your system is.

Graphics

The Radeon 780M (12 CUs / 768 shaders, up to 2,700 MHz) is capable of powering 4 monitors simultaneously with resolutions as high as SUHD 4320p. It will also have little issue hardware-encoding and hardware-decoding the most widely used video codecs (AV1, HEVC, AVC). As far as gaming is concerned, the thing will let you play most games at 1080p as long as you are fine with moderate quality settings. Long story short, this is the best iGPU money can buy, as of H2 2023.

Your mileage may vary depending on how high the CPU power limits are, how competent the cooling solution of your system is, how fast the RAM of your system is (there is no dedicated VRAM here).

Power consumption

This Ryzen 7 series chip has a long-term power limit (default TDP) of 35 W to 54 W, giving system makers a choice between improving battery life and making the system they're designing insanely fast. Either way, an active cooling solution is a must for a laptop or a mini-PC built around this APU.

The 7840HS is built with TSMC's 4 nm process for high, as of late 2023, energy efficiency.