AMD Ryzen 7 5825U vs AMD Ryzen 7 7840U

AMD Ryzen 7 5825U

The AMD Ryzen 7 5825U is a processor for thin and light laptops based on the Cezanne generation. It is part of the "Barcelo" refresh in early 2022 and offers 100 MHz higher clocked CPU cores compared to the old Ryzen 7 5800U. The R7 5825U integrates all eight cores based on the Zen 3 microarchitecture and is the fastest U-series processor at launch. They are clocked at 2 (guaranteed base clock) to 4.5 GHz (Turbo) and support SMT / Hyperthreading (16 threads). The chip is manufactured on the modern 7 nm TSMC process.

The new Zen 3 microarchitecture offers a significantly higher IPC (instructions per clock) compared to Zen 2. For desktop processors AMD claims 19 percent on average and in applications reviews showed around 12% gains at the same clock speed.

Performance

The average 5825U in our database is in the same league as the Ryzen 7 7735U and the Core i7-1270P, as far as multi-thread benchmark scores are concerned. Which is a really good result, as of early 2023.

Thanks to its decent cooling solution and a long-term CPU power limit of 37 W, the 2022 Envy x360 15 is among the fastest laptops built around the 5825U that we know of. It can be more than 15% faster in CPU-bound workloads than the slowest system featuring the same chip in our database, as of August 2023.

In addition to the eight CPU cores, the APU also integrates a Radeon RX Vega 8 GPU with 8 CUs at up to 2000 MHz. The dual channel memory controller supports DDR4-3200 and energy efficient LPDDR4-4266 RAM. Furthermore, 16 MB level 3 cache (up from 8 MB at the 4800U) can be found on the chip.

The TDP of the APU is specified at 15 Watt (default) and can be configured from 10 to 25 Watt by the laptop vendor (most chips are configured higher than 15 Watt). That means the chip is intended for thin and light laptops (but with fans).

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.