AMD Ryzen 7 8840HS vs AMD Ryzen 5 8645HS

AMD Ryzen 7 8840HS

The Ryzen 7 8840HS is a powerful processor (APU) of the Hawk Point family. This isn't an entirely new laptop chip; instead, it's a rebadged Ryzen 7 7840U, the slightly higher wattage of the 8840HS being the only meaningful difference between the two. The 8840HS has eight Zen 4 cores running at 3.3 GHz to 5.1 GHz that are SMT-enabled for a total of 16 processing threads, while the great Radeon 780M is responsible for 3D processing and similar duties. The 8840HS also features the Ryzen AI technology, now in its 2nd generation.

Architecture & Features

Hawk Point family chips are powered by the Zen 4 architecture, much like Phoenix and Dragon Range family chips are. That's not to say there is no difference between the three. With Hawk Point, AMD is betting big on generative AI; these processors are set to deliver an up to 40% increase in generative AI performance over 7040 series APUs, making apps like DaVinci Resolve and Adobe Photoshop more useful than ever before.

Unlike Zen 3, Zen 4 features AVX512 support and, thanks to a plethora of other improvements including larger caches/registers/buffers, is slated to bring a double-digit IPC improvement over the former.

Elsewhere, the 8840HS has 16 MB of L3 cache and support for super-fast DDR5-5600 and LPDDR5x-7500 RAM. The chip is compatible with USB 4 and therefore with Thunderbolt. It comes with 20 PCIe 4 lanes, giving NVMe SSDs up to 7.8 GB/s of throughput.

Systems built around this Ryzen 7 series APU are designed to run 64-bit Windows 11, 64-bit Windows 10, or Linux. Please note that this processor is not overclockable and neither is it user-replaceable. It gets soldered down for good instead (FP7, FP7r2, FP8 socket interfaces).

Performance

Since this is a 7840U in disguise that we are dealing with here, it is safe to expect the 8840HS to be about as fast as the Core i7-12650H, as far as multi-thread performance is concerned.

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

Graphics

The Radeon 780M has 12 CUs (768 shaders) purring away at up to 2,700 MHz. This is exactly the right iGPU for people looking for a bit more horsepower than what Intel's aging Xe options can provide. The Radeon will let you use up to 4 monitors with resolutions as high as SUHD 4320p and it will also HW-decode and HW-encode the most widely used video codecs (including AV1, HEVC and AVC) without breaking a sweat. In terms of gaming, the thing is good enough for 1080p and medium-to-low settings, as of late 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 28 W that laptop makers are free to tune to their liking, with values between 20 W and 30 W greenlighted by AMD. Either way, an active cooling solution is a must for any system powered by this chip.

The 8840HS is built with TSMC's 4 nm process for high, as of late 2023, energy efficiency.

AMD Ryzen 5 8645HS

The Ryzen 5 8645HS is an upper mid-range processor (APU) of the Hawk Point family. This isn't an entirely new chip; instead, the 8645HS is a rebadged Ryzen 5 7640HS. The 8645HS was brought to life in Q4 2023 and it has 6 SMT-enabled Zen 4 cores (12 threads) running at 4.3 GHz to 5.0 GHz. The Radeon 760M iGPU is responsible for carrying out 3D calculations and similar duties, and the Ryzen AI tech is now in its 2nd generation.

Architecture & Features

Hawk Point family chips are powered by the Zen 4 architecture, much like Phoenix and Dragon Range family chips are. That's not to say there is no difference between the three. With Hawk Point, AMD is betting big on generative AI; these chips are promised to deliver an up to 40% increase in generative AI performance over 7040 series APUs making apps like DaVinci Resolve and Adobe Photoshop even more powerful.

Unlike Zen 3, Zen 4 features AVX512 support and, thanks to a plethora of other improvements including larger caches/registers/buffers across the board, is slated to bring a double-digit IPC improvement over the former.

Elsewhere, the 8645HS has 16 MB of L3 cache and a super-fast DDR5-5600 / LPDDR5x-7500 RAM controller. USB 4 (and thus Thunderbolt) is supported natively and so is PCIe 4. In fact, 20 PCIe 4 lanes are on offer; data transfer speeds of up to 7.8 GB/s will be possible provided a sufficiently fast NVMe SSD is used.

Systems powered by this Ryzen 5 series chip are expected to run 64-bit Windows 11, 64-bit Windows 10, or Linux. Please note that the APU is not overclockable and neither will you be able to replace it with a faster one as it gets soldered to the motherboard permanently (FP7, FP7r2, FP8 socket interfaces).

Performance

Since the 8645HX is an 7640HS in disguise, it is safe to expect the APU to be about as fast as the Ryzen 9 5900HX, Ryzen 7 6800H, Ryzen 7 7736U and also the Core i5-12500H, as far as multi-thread performance is concerned.

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 760M has 8 CUs (512 shaders) running at up to 2,600 MHz. While this is not the best graphics adapter for gaming as it's only just fast enough for low quality settings and resolutions such as 1600 x 900, it will let you connect up to four SUHD 4320p monitors and it also HW-encodes and HW-decodes the most widely used video codecs such as AV1, HEVC and AVC without breaking a sweat.

Power consumption

The 8645HS has a long-term power limit (default TDP) of 35 W to 54 W, giving laptop makers a choice between improving battery life and giving the system they are working on more oomph. Either way, an active cooling solution is a must for any system powered by the chip.

This Ryzen 5 series APU is built with TSMC's 4 nm process for high, as of late 2023, energy efficiency.