AMD Ryzen 5 6600U vs AMD Ryzen 5 7640U

AMD Ryzen 5 6600U

The AMD Ryzen 5 6600U is a processor for thin and light laptops based of the Rembrandt generation. The Ryzen packs six of the eight cores based on the Zen 3+ microarchitecture. They are clocked at 2.9 (guaranteed base clock) to 4.5 GHz (Turbo) and support SMT / Hyperthreading (12 threads). The chip is manufactured on the modern 6 nm process at TSMC. Compared to the similar R5 6600H, the 6600U offers a lower base clock speed and a lower TDP.

In the 6000 series, AMD finally switched to the current RDNA 2 graphics architecture for the iGPU. The 6600U only offers the small Radeon 660M with 6 of the 12 CUs enabled and 1.9 GHz max. clock rate.

The new Zen 3+ is a refresh of the Zen 3 architecture and should not offer a lot of changes. The chip itself however, offers a lot of new features, like support for USB 4 (40 Gbps), PCI-E Gen 4, DDR5-4800MT/s or LPDDR5-6400MT/s, WiFi 6E, Bluetooth LE 5.2, DisplayPort 2, and AV1 decode.

Performance

The average 6600U in our database matches the Ryzen 7 5800U in multi-thread performance, making this Ryzen 5 series chip a great CPU for most activities as of mid 2023.

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

Power consumption

This Ryzen 5 series chip has a default TDP, also known as the long-term power limit, of 15 W to 28 W, the expectation being that laptop makers will go for a higher value in exchange for higher performance. Either way, that's too much to allow for passively cooled designs.

The R5 6600U is manufactured on TSMC's 6 nm manufacturing process for good, as of mid 2023, energy efficiency.

AMD Ryzen 5 7640U

The Ryzen 5 7640U is a Phoenix family processor that was unveiled in H1 2023. The mid-range laptop chip has 6 SMT-enabled cores (12 threads) running at 3.5 GHz to 4.9 GHz. Those Zen 4 architecture cores are mated to the Radeon 760M integrated graphics adapter; the latter is about as fast as the aging Intel Iris Xe options.

Furthermore, the 7640U is one of the first AMD processors to support Ryzen AI which is AMD's answer to Intel's DL Boost and GNA technologies.

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 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 deliver a double-digit IPC improvement.

Elsewhere, the 7640U has 16 MB of L3 cache and USB 4 support (therefore, Thunderbolt is supported as well). The chip is compatible with DDR5-5600 and LPDDR5x-7500 RAM which is really impressive as of H1 2023.

A system powered by this Ryzen 5 will have access to twenty PCIe 4 lanes; this means a speedy enough NVMe SSD will be able to deliver speeds up to 7.8 GB/s.

Systems powered by this APU are expected to run 64-bit Windows 11, 64-bit Windows 10, or Linux. Like most laptop chips, the 7640U is neither overclockable nor user-replaceable. It gets soldered down for good (FP7, FP7r2, FP8 socket interfaces).

Performance

While we have not tested a single system built around the 7640U as of December 2023, it's safe to expect the chip to be at least 10% faster than the Zen 3 Plus-powered Ryzen 5 6600U (6 cores, 12 threads, up to 4.5 GHz).

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 760M has 8 CUs (512 shaders) running at up to 2,600 MHz. While not great for gaming (unless you are fine with resolutions such as 900p and low detail settings), the iGPU will let you use up to 4 monitors with resolutions as high as SUHD 4320p. It also HW-decodes and HW-encodes the most widely used video codecs including AV1, HEVC, AVC without breaking a sweat.

Power consumption

The 7640U has a long-term power limit (default TDP) of 28 W that laptop makers are free to change to anything between 15 W and 30 W. Either way, an active cooling solution is a must for any system powered by the chip.

Last but not the least, the 7640U is manufactured on TSMC's 4 nm process for high, as of late 2023, energy efficiency.