Intel Core i7-1355U vs AMD Ryzen 5 5500U

Intel Core i7-1355U

The Intel Core i7-1355U is a high-end mobile CPU for thin and light laptops based on the Alder Lake architecture (Raptor Lake-U / RPL-U series). It was announced in early 2023 and offers 2  performance cores (P-cores, Golden Cove architecture) and 8 efficient cores (E-cores, Gracemont architecture). The P-cores support Hyper-Threading leading to 12 supported threads when combined with the E-cores. The clock rate ranges from 1.7 to 5 GHz on the performance cluster and 1.2 to 3.7 GHz on the efficient cluster. The performance of the E-cores should be similar to old Skylake cores (compare to the Core i7-6700HQ). All cores can use up to 12 MB L3 cache. The CPU supports "Essentials" vPro management features. Compared to the P-series (28W) or H-series (45W), the 15W TDP may limit the sustained performance.

Performance

Thanks to the high clock speed, the Core i7-1355U should perform slightly better than the older core i7-1265U (up to 4.8 GHz). The faster i7 like the i7-1365U models offer only higher clock rates (and a faster iGPU).

Architecture

The integrated memory controller supports various memory types up to LPDDR5-6400. The Thread Director (in hardware) can support the operating system to decide which thread to use on the performance or efficient cores for the best performance. For AI tasks, the CPU also integrates GNA 3.0 and DL Boost (via AVX2). Quick Sync in version 8 is the same as in the Rocket Lake CPUs and supports MPEG-2, AVC, VC-1 decode, JPEG, VP8 decode, VP9, HEVC, and AV1 decode in hardware. The CPU still only supports PCIe 4.0 x8 for a GPU and two PCIe 4.0 x4 for SSDs.

The integrated graphics card is based on the Xe-architecture and offers all 96 EUs (Execution Units) operating at up to 1.3 GHz.

Power consumption

This Core i7 CPU is rated at a TDP of 15W (base power, PL1) and a maximum turbo power of 55W (PL2). The RPL-U processors are built in a further improved Intel 7 process (10nm SuperFin) that allows higher clock rates.

AMD Ryzen 5 5500U

The AMD Ryzen 5 5500U is a hexa-core APU of the Lucienne product family designed for use in ultra-thin, upper mid-range laptops. The processor was unveiled in H1 2021; its six CPU cores are based on the Zen 2 microarchitecture. The cores run at 2.1 GHz (base clock speed) to 4 GHz (highest Boost frequency possible) and feature the thread-doubling SMT technology for a total of 12 threads. The chip is manufactured on the modern 7 nm TSMC process.

One could be forgiven for thinking Ryzen 5 5500U is a renamed Ryzen 5 4500U - which is not the case. Ryzen 5 5500U is most similar to Ryzen 5 4600U, the most noteworthy difference between the two being the faster iGPU model of the former.

In the meantime, Ryzen 5 5600U got a little more lucky; it is based on the newer Zen 3 architecture and it also has higher clock speeds than what a 5500U can boast of.

Architecture

While Ryzen 5 5500U and Ryzen 7 5700U are Zen 2-based processors, the neighbouring Ryzen 5 5600U and Ryzen 7 5800U use AMD's brand-new Zen 3 architecture. This makes the former two a generation older than their names suggest. Still, Zen 2 is nothing to sneeze at, with its high performance-per-Watt and performance-per-MHz figures.

Ryzen 5 5500U supports dual-channel DDR4-3200 and quad-channel LPDDR4-4266 RAM and has 8 MB of Level 3 cache. Unlike desktop-grade Ryzen 5000-series processors, Ryzen 5 5500U is limited to PCI-Express 3.0 (not PCI-Express 4.0; no 7.9 GB/s NVMe SSDs here).

The processor gets soldered permanently on to the motherboard (FP6 socket interface) and is thus not user-replaceable.

Performance

Multi-thread performance is most comparable to the Ryzen 7 4700U and the Core i7-10850H, which is nothing to sneeze at. The Ryzen will have no trouble chewing through pretty much any workload, as of mid 2022.

Thanks to its decent cooling solution and a long-term CPU power limit of around 27 W, the Lenovo IdeaPad Flex 5 14ALC05-82HU006NGE is among the fastest laptops built around the 5500U that we know of. It can be more than 30% faster in CPU-bound workloads than the slowest system featuring the same chip in our database, as of August 2023.

Graphics

The Radeon RX Vega 7 iGPU has 7 CUs at its disposal (64 x 7 = 448 unified shaders) running at up to 1,800 MHz. Its real-life performance is close to what we've seen from GeForce MX250 and Iris Xe Graphics G7 (80 EUs); Mass Effect Legendary Edition (2021) runs well at 1080p resolution, low-to-medium settings, to give you an example. As the iGPU has no VRAM of its own, it is paramount that fast system RAM is used.

The graphics adapter definitely supports UHD 2160p monitors at 60 Hz. It will have no trouble HW-decoding HEVC, AVC, VP9, MPEG-2 and other popular video codecs. There is no AV1 support; AV1-encoded videos will be software-decoded, which six Zen 2 cores will handle with ease.

Power consumption

The APU has a default TDP (also known as the long-term Power Limit) of 15 W. That can be changed to anything between 10 W and 25 W by laptop makers and in many cases they do go for a value higher than 15 W to achieve higher performance levels. On the other hand, by going for the lowest value, it will be possible to build a passively cooled system around the Ryzen 5.

The R5 5500U is manufactured using TSMC's 7 nm process for average, as of mid 2023, average efficiency.