AMD Ryzen 7 7840U vs AMD Ryzen 7 4980U

AMD Ryzen 7 7840U

The Ryzen 7 7840U is a powerful laptop processor (APU) of the Phoenix product family. Its eight Zen 4 cores run at 3.3 GHz to 5.1 GHz and are SMT-enabled for a total of 16 processing threads. The great Radeon 780M is responsible for 3D processing and similar duties; the 7840U also features Ryzen AI which is AMD's answer to Intel's GNA and DL Boost.

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.

More importantly, Zen 4 introduces some rather solid 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 7840U 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 thus with Thunderbolt. It comes with 20 PCIe 4 lanes for NVMe SSD speeds of up to 7.8 GB/s.

Systems built around the 7840U 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

The average 7840U in our extensive database is about as fast as the Core i7-12650H, as far as multi-thread benchmark scores are concerned. This means the Ryzen 7 APU packs quite a wallop, as of mid 2023.

Thanks to its decent cooling solution and a long-term CPU power limit of 35 W, the Framework Laptop 13.5 is among the fastest systems powered by the 7840U that we know of. It can be about 30% faster than the slowest system featuring the same chip in our database, as of December 2023.

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. Laptop makers are free to change that value significantly, with values as low as 15 W and as high as 30 W greenlighted by AMD. Either way, an active cooling solution is a must for any system powered by this chip.

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

AMD Ryzen 7 4980U

The AMD Ryzen 7 4980U is a Renoir family processor designed for certain Microsoft Surface systems. 4980U has eight Zen 2 cores clocked at 2.0 GHz (base clock speed) to 4.4 GHz (Boost) with thread-doubling SMT tech enabled for a total of 16 threads. The chip is manufactured on the modern 7 nm TSMC process and partly thanks to that AMD promises a 2x improvement in performance-per-Watt over Ryzen 3000 series mobile CPUs.

Architecture

The Zen 2 microarchitecture has brought a sizeable per-thread performance boost compared to the outgoing Zen+ parts. Renoir product family is also the first to introduce 8-core ULV processors to laptop market, keeping power consumption within reasonable limits. This AMD processor family is very impressive from most perspectives. One of the disatvantages to keep in mind is the lack of PCI-Express 4 support, meaning these blazing-fast NVMe SSDs will be limited to 3.9 GB/s tops.

Ryzen 7 4980U is designed to work with quad-channel LPDDR4 memory at up to 4,267 MHz. 8 MB of Level 3 are present in this chip. The Ryzen 7 gets soldered straight to the motherboard (FP6 socket) and is thus not user-replaceable. Please go to our Renoir hub page for more information on the product family.

Performance

The 4980U is the fastest U-class Ryzen 4000 series chip. As such, its clock speeds are 200 MHz higher (both the base one and Boost one) than what the Ryzen 7 4800U has.

It is thus hardly surprising that the average 4980U in our database is in the same league as the Ryzen 7 5800U and also the Core i7-1260P, as far as multi-thread benchmark scores are concerned.

Graphics

In addition to its eight CPU cores, the Ryzen 7 also features the Radeon RX Vega 8 graphics adapter with 8 CUs (= 512 shaders) at up to 1,950 MHz. This iGPU is compatible with FreeSync and DirectX 12 and is able to HW-decode AVC, HEVC, VP9-encoded videos (no AV1 support here). Vega 8 is capable of outputting UHD 2160p60 video signal to several monitors and, similar to Intel's Iris Xe (80 EUs), is good enough for a bit of light gaming on the go, provided one is content with sub-1080p resolutions and low/medium quailty presets.

Power consumption

The APU has a default TDP, also known as the long-term power limit, of 15 W; much like it is with other U-class Ryzen 4000 chips, AMD is fine with laptop makers (Microsoft, in this case) changing that value to anything between 10 W and 25 W.

The 7 nm TSMC process this Ryzen 7 is built with makes for above average, as of mid 2022, energy efficiency.