What is Cascade Lake Processor? (Explained)

What is Cascade Lake Processor?

Cascade Lake is the codename of the 14 nm microarchitectures of the workstation, server, and enthusiast lines of processors from Intel.

Technically, Cascade Lake CPU follows the PAO or Process Architecture Optimization model of Intel and is basically an optimization of the Skylake line of processors.

KEY TAKEAWAYS

  • Cascade Lake is the codename of the processors from Intel built on a 14 nm manufacturing process and belongs to the 2nd generation.
  • According to a statement from Intel, the Cascade Lake processors are supposed to be the first microarchitecture type from them that supports 3D XPoint-based memory modules.
  • Launched in April 2019, this specific line of processors offer support for other useful features such as Deep Learning Boost instructions, mitigations for Meltdown and Specter and more.
  • The Cascade Lake processors are available in different variants such as servers, enthusiasts, and workstation class, offering both advanced and scalable performance.
  • In comparison to the earlier models and its predecessor, Skylake, the Cascade Lake processors have improved speed, efficiency, performance and security.

Understanding Cascade Lake Processor

What is Cascade Lake Processor

Cascade Lake is the codename of the microarchitecture of Intel processors.

These 2nd generation processors typically come with Intel C620 series chipsets and offer significantly high performance even with AI workloads.

With features like Deep Learning Boost, the processor combines different IoT workloads as well and can deal with a large dataset and ensure transactions in real time – well, almost.

The Intel Cascade Lake processors come with significant enhancements in specific areas such as:

  • Speed
  • Performance
  • Security
  • Efficiency

Some of the top specifications of this particular line of processors from Intel include:

  • Up to 28 cores
  • Up to 3.8 GHz of non-AVX-based frequency
  • Multi-socket support
  • Up to 3 UPI channels for each CPU
  • 6 channel support for DDR4 memory for each CPU with up to 2933 MT/s speed
  • Memory capacity ranging between 1 TB and 4.5 TB per CPU
  • Integrated Intel Ethernet Connection X722
  • 48 lanes of PCIe 3.0 in each CPU
  • PCIe, USB, and SATA support
  • SSD, Ethernet, and FPGA peripheral connection support

With all these features, the functionality of the Cascade Lake processors from Intel is highly enhanced which helps them to offer the following:

  • Higher per-core performance
  • Balanced energy efficiency
  • Higher performance per watt
  • More reliability
  • Extended memory support

The best part of these processors is that they allow hardware mitigations with their enhanced security for the Meltdown and Specter vulnerabilities.

In case you do not know, these two vulnerabilities can exist in computers, mobile devices, and even in the cloud infrastructure.

These vulnerabilities can steal data when a program is being processed in a system and there will be no traces of it left in the traditional log files.

Other significant benefits offered by the Cascade Lake processors, apart from the above, include the following:

  • Faster evaluations with the help of Intel Select Solutions
  • Stronger and more capable platforms that can be used for data-intensive enterprise
  • Next-gen capabilities that are optimized for cloud implementations, next-gen virtual networks and 5G-ready networks
  • High-performing data analytics and breakthrough HPC

General information

Here are a few facts about the Intel Cascade Lake processors at a glance:

  • Technology node – 14 nanometers Tri-Gate transistors
  • Architecture and instructions – x86-64
  • Cores – 4 to 56
  • GPU – None
  • Hyperthreading – Turned on
  • Turbo Boost – Turned on with Turbo Frequency up to 3.90 GHz for non-AVX and up to 3.8 GHz for AVX2 and AVX-512
  • SocketsLGA 2066, LGA 3647, and BGA 5903
  • Predecessor – Skylake-X desktop, Skylake-SP server
  • Successor – Ice Lake 1S and 2S systems, Cooper Lake 4S and 8S systems
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Instruction extensions

This processor supports different instruction extensions such as:

  • AES-NI or Advanced Encryption Standard New Instructions
  • CLMUL or Carry-less Multiplication
  • RDRAND or Read Random
  • MPX or Memory Protection Extensions
  • TXT or Text File extension
  • MMX or MultiMedia eXtensions
  • SSE or Streaming SIMD Extensions, along with all its variants such as SSE2, SSE3, SSSE3, SSE4, SSE4.1, SSE4.2
  • AVX or Advanced Vector Extensions, along with AVX2 and AVX-512
  • FMA3 or Fused Multiply Add
  • TSX or Transactional Synchronization Extensions
  • VT-x and VT-d or Virtualization extensions

Main features

Some of the key features of the Intel Cascade Lake processors are as follows:

  • Intel Deep Learning Boost – This feature helps in expediting the performance of the CPU while handling AI, vision, or deep learning workloads. The inference output performance of it is enhanced up to 14 times as compared to the earlier generation processors.
  • Intel Optane DC Persistent Memory – This feature also helps in expediting the process while dealing with complex workloads and reduces time to offer insights. This is a revolutionary memory product which is persistent, large and affordable.
  • Integrated Intel Quick Assist Technology – Also referred to as Intel QAT, this feature facilitates accelerating cryptography and data compression. This integrated feature also helps in freeing up the host processor and enhances data protection while transmitting across storage, network, server, and VM.
  • Intel Resource Director Technology for Determinism – This feature offers extended Quality of Service (QoS) and ensures proper memory bandwidth assignment.
  • Enhanced security – Improved security features offered by this processor allow hardware mitigations for Meltdown and Specter vulnerabilities, different side-channel exploits, and help in protecting data and the system by fortifying the platform to prevent any malicious attacks.

Different variants of Cascade Lake processors are available with different brand names and families.

The different names of these processors are as follows:

  • Cascade Lake X, abbreviated as CSL-X, which is targeted at the HEDT or High End Desktop and Enthusiasts market segment
  • Cascade Lake W, abbreviated as CSL-W, which is targeted at the enterprise or business workstations market segment
  • Cascade Lake SP, abbreviated as CLX-SP, which is targeted at the server class scalable processors market segment
  • Cascade Lake AP, abbreviated as CLX-AP, which is targeted at the server class advanced processors market segment

As for the families of Intel Cascade Lake processors, there are five of them, each with different features, such as:

  • The Xeon W processors that are designed as high performance workstation processors come with a number of cores ranging from 8 to 28 and support features like HT, TBT, and one AVX 512 unit.
  • The Xeon Bronze processors that are designed as high performance, cost-effective entry-level processors come with 6 cores and support features like one AVX 512 unit, and two UPI links offering scalability up to 2.
  • The Xeon Silver processors that are designed as high performance, efficient, and low power, mid range processors come with a number of cores ranging from 8 to 16 and support features like HT, TBT, one AVX 512 unit, and two UPI links offering scalability up to 2.
  • The Xeon Gold 5000 processors that are designed as high performance processors come with a number of cores ranging from 4 to 18 and support features like HT, TBT, one AVX 512 unit, and two UPI links offering scalability up to 4.
  • The Xeon Gold 6000 processors that are designed as high performance processors come with a number of cores ranging from 8 to 24 and support features like HT, TBT, two AVX 512 units, and three UPI links offering scalability up to 4.
  • The Xeon Platinum processors that are designed as high performance and flexible processors come with a number of cores ranging from 4 to 28 and support features like HT, TBT, two AVX 512 units, and three UPI links offering scalability up to 8.
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Memory subsystem

Technically, the memory hierarchy of the Intel Cascade Lake processors is similar to that of its predecessor, Skylake, and is as follows.

The L0 µOP cache comes with the following features:

  • 1,536 µOps per core
  • 8-way set associative
  • 32 sets
  • 6-µOP line size
  • Statically partitioned between threads included with L1I

The Level 1 instruction cache comes with the following features:

  • 32 KiB per core
  • 8-way set associative
  • 64 sets
  • 64 B line size
  • Competitively distributed by the threads per core

The Level 1 data cache comes with the following features:

  • 32 KiB per core
  • 8-way set associative
  • 64 sets
  • 64 B line size
  • Competitively divided by threads per core
  • 4 cycles for fastest load-to-use allowing simple pointer access
  • 5 cycles for complex addresses
  • 128 B per cycle load bandwidth
  • 64 B per cycle store bandwidth
  • Write-back policy

The Level 2 cache comes with the following features:

  • 1 MiB per core
  • 16-way set associative and inclusive
  • 64 B line size
  • 64 B per cycle bandwidth to L1
  • 14 cycles latency
  • Write-back policy

The Level 3 cache comes with the following features:

  • 1.375 MiB per core
  • 11-way set associative
  • Distributed across all cores
  • 2,048 sets
  • 64 B line size
  • 50 to 70 cycles of latency
  • Non-inclusive victim cache
  • Write-back policy
  • Snoop Filter with 2,048 sets, 12-way set associative

The system’s Dynamic Random Access Memory or DRAM comes with the following features:

  • 6 channels
  • DDR4 support up to 2933 MT/s
  • RDIMM or Registered Dual Inline Memory Module
  • LRDIMM or Load Reduced Dual Inline Memory Module
  • Bandwidth of up to 23.47 GB/s
  • Average combined bandwidth of 140.8 GB/s

Translation Lookaside Buffer

The Cascade Lake processors also come with a Translation Lookaside Buffer that consists of a dedicated L1 TLB for instruction cache called the ITLB and one for data cache called the DTLB.

In addition to that, there is also another unified L2 TLB called the STLB. All of these come with diverse features as follows:

ITLB

The ITLB allows two types of page translations.

As for 4 KiB page translations, the features are as follows:

  • 128 entries
  • 8-way set associative
  • Dynamic partitioning

As for 2 MiB / 4 MiB page translations, the features are as follows:

  • 8 entries per thread
  • Fully associative
  • Duplicated for every thread

DTLB

The DTLB allows three types of page translations with different features.

As for 4 KiB page translations, the features are as follows:

  • 64 entries
  • 4-way set associative
  • Fixed partition

As for 2 MiB / 4 MiB page translations, the features are as follows:

  • 32 entries
  • 4-way set associative
  • Fixed partition

As for 1G page translations, the features are as follows:

  • 4 entries
  • 4-way associative
  • Fixed partition

STLB

The STLB allows two types of page translations with different features.

As for 4 KiB + 2 MiB page translations, the features are as follows:

  • 1536 entries
  • 12-way set associative
  • Fixed partition

As for 1 GiB page translations, the features are as follows:

  • 16 entries
  • 4-way set associative
  • Fixed partition

Connectivity Support

Typically, the on-chip architecture of the Cascade Lake processors, especially the SP variants, use a similar mesh layout as that of the Skylake processors.

Here, the Level 3 cache and the cores are typically arranged in rows and columns and not in a ring architecture, as it was used in the previous Xeon processors.

These processors normally support up to three Intel Ultra Path Interconnect or UPI links that run at a high speed of usually up to 10.4 Gigatransfers per second (GT/s).

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Each of these links comes with separate lanes that allow transfer of data in two directions.

For three links, the total full-duplex bandwidth is 62.4 GB/s, and for those with only two links, the total full-duplex bandwidth is 41.6 GB/s.

For the inter-node network the Cascade Lake processors usually use two PCIe or Peripheral Component Interconnect Express interfaces, one for each socket.

This offers a bandwidth in excess of 15 GB/s in each direction with the use of the Endpoint Detection and Response or EDR technology of 100 GBit/s.

Cascade Lake vs Ice Lake

  • Typically, the Intel Cascade Lake processors belong to the 2nd generation of Intel processors, while, in comparison, the Intel Ice Lake processors belong to the 3rd generation of CPU lines.
  • The number of cores supported by the Cascade Lake processors per socket typically ranges from 4 cores to 28 cores. On the other hand, the Ice Lake processors can support anywhere from 8 cores and scale up to 40 cores per socket.
  • In terms of caching and access, the Intel Ice Lake processors allow much faster caching as well as much faster access to data, as opposed to the 2nd generation Cascade Lake processors.
  • The Intel Cascade Lake processors typically cannot offer UPI speed as fast as the Intel Ice Lake processors offer. The UPI speed is the interconnect speed from one processor to the other.
  • The Cascade Lake processors also cannot offer as high bandwidth between the CPUs as the Intel Ice Lake processors can.
  • There are as many as six memory channels per processor in the case of the 2nd generation Cascade Lake. On the other hand, in the Ice Lake processors, there are as many as 8 memory channels per processor, therefore offering higher memory capacity.
  • Talking about memory, the Cascade Lake processors can support a speed of up to 2933 MT/s, offering up to 13 GiBs per socket. In comparison, the Ice Lake processors will allow you to populate up to 16 GiBs per socket at a higher speed.
  • Considering the PCI Express support, the 2nd generation Cascade Lake processors support Gen 3 PCIe slots and up to only 48 lanes in total. The Intel Ice Lake processors, on the other hand, support Gen 4 PCIe lanes and each socket supports up to 64 lanes in total.
  • The Intel Cascade Lake processor supports Intel Optane persistent memory of the 100 series, but in comparison, the Ice Lake processors support Optane persistent memory of the 200 series.

Which Generation is Cascade Lake?

The Cascade Lake processors belong to the 2nd generation of Intel processors.

Typically, it is the earlier name of the 2nd generation of Intel Xeon Scalable processors.

Conclusion

The Cascade Lake CPUs the successors of Intel Skylake and predecessors of Intel Ice Lake and Cooper Lake processors.

These 2nd generation CPUs come with a lot of upgrades in different fields over and above speed and performance and come with a lot of useful features that help in many specific hardware mitigations.