During CES 2021, Intel unveiled its 11th-generation CPUs from its Intel Core lineup in the form of two architectures: Tiger Lake-H for laptops and Rocket Lake-S for desktops. Both disparate since while TL is built under Intel’s 10 nm process, RKL is built on the 14 nm node and each has its own architecture. In this article we will talk about the desktop.
Rocket Lake is actually nothing more than an Ice Lake, but with the main difference that Intel has designed it so that it can be manufactured under its 14 nm node, something that surprises, since the fact of using one node or another is not something simple and requires the entire revision of the entire chip, as well as certain optimizations because, contrary to the usual step in which a version with a more advanced node is designed, in this case Intel has gone to a less advanced node.
The paradox is that we are facing the first major change in years if we talk about Intel architectures for desktop computers, since the changes at the IPC level from the sixth generation with Skylake to the tenth with Comet Lake have been null, the reason is that Intel has spent four years using the same core and releasing versions of the same processor with minor improvements.
All this while they were polishing their already veteran 14nm node, hoping that the 10nm node would have enough performance in production to make the leap. Due to these problems, Intel made the decision to make a 14 nm version of its Ice Lake in order to face the Gen 11 of the Intel Core and as prior to Alder Lake.
The general architecture of the Intel Rocket Lake-S
Rocket-Lake S is an 8-core processor with Hyperthreading capability, these are based on Intel’s Cypress Cove architecture, which is a port at 14 nm from the Sunny Cove of Ice Lake.
On the other hand, where if there are changes in the part of the integrated GPU that is now an Intel Xe LP of 32 Execution Units, equivalent to an AMD GPU of 4 Compute Units, so in the graphic section its iGPU only complies with what minimum of minimum. The really remarkable thing? The fact of having a hardware video CODEC for AV1, so the CPU will not suffer when it comes to playing those videos.
Regarding the I / O, Intel has decided to place a 20-rail PCIe interface, which means that the most common configuration that we are going to see is the dedicated graphics card together with an SSD unit, the problem is that the CPU does not integrate other I / O interfaces inside, as it uses Intel’s Z590 chipset.
Z590 chipset, the companion of the Rocket Lake-S
If there is something good about Intel CPUs it is the use of the Direct Media Interface, an interface to communicate the Northbridge integrated in the processor with the Southbridge of the same. At AMD they use PCI Express lanes for this, so we can say that the 24 lanes of the AMD CPUs via IO Hub, are equivalent to the 20 PCIe lanes of the Intel Rocket Lake-S + 8 vias DMI.
The downside is that unlike AMD where the Southbridge integrated in the CPU provides a USB controller, here the Z590 chipset is needed, something that is purposely done by Intel to sell the Z590. The chipset supports up to 3 USB ports 20 Gb / s 3.2 2.2, 10 USB 3.2 Gen 2 × 1 10 Gb / s ports, 10 USB 3.2 Gen 2 × 1 5 Gb / s ports, and up to 14 USB 2.0 ports.
If we talk about other I / O ports, it supports up to 6 SATA 6 Gb / s ports for conventional hard drives that can be placed in a RAND 1,5, 10 configuration. Integrated LAN for network connection by ethernet cable, WiFi Integrated with WiFi support and 6 24 PCI Express 3.0 lanes.
Cypress Cove, the heart of Rocket Lake-S based in Sunny Cove
The Cypress Cove core results in the first jump in IPC of Intel desktop CPUs since Skylake, so the performance comparing core to core at the same speed is superior to the previous generation.
As it is a 14 nm port of Sunny Cove, it is not a new architecture, it is more, it was presented at the Intel Architecture Days of 2018, so the architecture at the launch date of Rocket Lake-S is more than two years old. of existence.
It is surprising that Intel has not decided to launch a Tiger Lake for desktop, since the Willow Cove core of these has a performance between 10% and 20% at the same clock speed and better consumption than the Sunny Cove / Cypress Cove. This disparity in Intel’s Gen 11 makes us think that Rocket Lake-S is a parallel project to Tiger Lake and that it was much more expensive for Intel to cancel the project than to continue with its execution.
Cypress Cove / Sunny Cove Core Specifications
Intel has not given specific details of Cypress Cove beyond that it is the 14 nm version of the Sunny Cove that they presented more than two years ago, in any case, here is a list of its technical characteristics:
- Firstly, its CPI has risen, averaging 19% in some benchmarks compared to Skylake-based cores.
- The micro-cache for the micro-instructions which is 50% larger, going from 1536 entries to 2.25k entries.
- The IDQ has also been improved, going from 70 MicroOps per second compared to 64 of previous generations.
- The processor prefetchers used during the instruction fetch phase, as well as the jump prediction unit used to analyze the code beforehand and find conditional jumps has been improved.
- Regarding the part dedicated to the decoding of instructions, the paths are now 20% wider, so there is less contention, the planner of the instructions in charge of programming the sending to the execution units of the CPU from 97 to 160 inputs. And the sending of instructions to the execution units from the Dispatch unit has gone from 8 to 10.
- The virtual address generation unit, AGU, has also been improved.
- As for the cache, the first-level data cache has gone from 32 KB to 48 KB, while the L2 cache is 512 KB.
- In Cypress Cove, the top-level cache is L3 per core is 2MB, making a total of 16MB for the 8-core configuration.
As you can see, the architecture of the Rocket Lake cores is an important change compared to the 6th to 10th generation Intel Core, in terms of performance per core, despite the fact of not having a 10-core configuration makes that loses in multicore performance versus Comet Lake with that setup,
