When you create a virtual machine (VM) or bare metal instance using Compute Engine, you specify a machine series and a machine type for the instance. Each machine series is associated with one or more CPU platforms. If there are multiple CPU platforms available for a machine series, you can select a minimum CPU platform for the compute instance.
A CPU platform offers multiple physical processors, and each of these processors is referred to as a core. For the processors available on Compute Engine, a single CPU core can run as multiple hardware threads through Simultaneous multithreading (SMT), which is known on Intel processors as Intel Hyper-Threading Technology. On Compute Engine, each hardware thread is called a virtual CPU (vCPU). Some machine series, such as C4A, T2D, and H3, don't use SMT, and each vCPU instead represents a core. When vCPUs are reported to the VM as occupying different virtual cores, Compute Engine ensures that these vCPUs never share the same physical core.
The machine type of your compute instance specifies its number of vCPUs, and you can infer its number of physical CPU cores using the default vCPU per core ratio for that machine series:
- For the C4A, Tau T2D, Tau T2A, and H3 machine series, VMs always have one vCPU per core.
- For all other machine series, the compute instances have two vCPUs per core by default.
You can optionally set the number of threads per core , to a non-default value, which might benefit some workloads. Importantly, when you do this, the machine type of your compute instance no longer reflects the correct number of vCPUs. Instead, the pricing and number of physical CPU cores remains the same as it would be for the default two vCPUs per core ratio, and the number of vCPUs is half of the value indicated by the machine type.
Arm processors
For Arm processors, Compute Engine uses one thread per core. Each vCPU maps to a physical core with no SMT.
The following table describes the Arm processors that are available for Compute Engine instances.
| CPU processor and SKU | Supported machine series and types |
|---|---|
| Google Axion™ Processors | C4A |
| Ampere Altra Q64-30 | Tau T2A |
x86 processors
For most x86 processors, each vCPU is implemented as a single hardware thread. The H3 machine series is the exception, with one vCPU representing one physical core.
Intel processors
On Intel Xeon processors, Intel Hyper-Threading Technology supports multiple threads running concurrently on each core. The machine type of your compute instance determines the number of its vCPUs and memory.
| CPU processor | Processor SKU | Supported machine series and types | Base frequency (GHz) | All-core turbo frequency (GHz) | Single-core max turbo frequency (GHz) |
|---|---|---|---|---|---|
| Intel Xeon Scalable Processor (Emerald Rapids) 5th generation |
|||||
| Intel® Xeon® Platinum 8581C Processor |
2.3 | 3.1 | 4.0 | ||
| Intel® Xeon® Platinum 8581C Processor |
2.1 | 2.9 | 3.3 | ||
| Intel Xeon Scalable Processor (Sapphire Rapids) 4th generation |
Intel® Xeon® Platinum 8490H Processor | 1.9 | 2.9 | 3.5 | |
| Intel® Xeon® Platinum 8481C Processor | 2.2 | 3.0 | 3.0 | ||
| Intel® Xeon® Platinum 8481C Processor | 2.0 | 3.8 | 2.9 | ||
| Intel Xeon Scalable Processor (Ice Lake) 3rd Generation |
Intel® Xeon® Platinum 8373C Processor |
2.6 | 3.4 | 3.5 | |
| Intel Xeon Scalable Processor (Cascade Lake) 2nd Generation |
|||||
| Intel® Xeon® Gold 6268CL Processor | 2.8 | 3.4 | 3.9 | ||
| Intel® Xeon® Gold 6253CL Processor | 3.1 | 3.8 | 3.9 | ||
| Intel® Xeon® Platinum 8280L Processor | 2.5 | 3.4 | 4.0 | ||
| Intel® Xeon® Platinum 8273CL Processor | 2.2 | 2.9 | 3.7 | ||
| Intel Xeon Scalable Processor (Skylake) 1st Generation |
Intel® Xeon® Scalable Platinum 8173M Processor | 2.0 | 2.7 | 3.5 | |
| Intel Xeon E7 (Broadwell E7) | Intel® Xeon® E7-8880V4 Processor | 2.2 | 2.6 | 3.3 | |
| Intel Xeon E5 v4 (Broadwell E5) | Intel® Xeon® E5-2696V4 Processor | 2.2 | 2.8 | 3.7 | |
| Intel Xeon E5 v3 (Haswell) | Intel® Xeon® E5-2696V3 Processor | 2.3 | 2.8 | 3.8 | |
| Intel Xeon E5 v2 (Ivy Bridge) | Intel® Xeon® E5-2696V2 Processor | 2.5 | 3.1 | 3.5 | |
| Intel Xeon E5 (Sandy Bridge) | Intel® Xeon® E5-2689 Processor | 2.6 | 3.2 | 3.6 |
*N2 machine types that have 96 or more vCPUs require the Intel Ice Lake CPU.
AMD processors
AMD processors provide optimized performance and scalability using SMT. In almost all cases, Compute Engine uses two threads per core, and each vCPU is one thread. Tau T2D is the exception where Compute Engine uses one thread per core and each vCPU maps to a physical core. The machine type of your compute instance determines the number of its vCPUs and memory.
| CPU processor | Processor SKU | Supported machine series | Base frequency (GHz) | Effective frequency (GHz) | Max boost frequency (GHz) |
|---|---|---|---|---|---|
| AMD EPYC Genoa 4th Generation |
AMD EPYC™ 9B14 | 2.6 | 3.3 | 3.7 | |
| AMD EPYC Milan 3rd Generation |
AMD EPYC™ 7B13 | 2.45 | 2.8 | 3.5 | |
| AMD EPYC Rome 2nd Generation |
AMD EPYC™ 7B12 | 2.25 | 2.7 | 3.3 |
Frequency behavior
The previous tables describe the hardware specifications of the CPUs that are available with Compute Engine, but keep the following points in mind:
Frequency: A PC's frequency, or clock speed, measures the number of cycles the CPU executes per second, measured in GHz (gigahertz). Generally, higher frequencies indicate better performance. However, different CPU designs handle instructions differently, so an older CPU with a higher clock speed can be outperformed by a newer CPU with a lower clock speed because the newer architecture deals with instructions more efficiently.
Base frequency: The frequency at which the CPU runs when the system is idle or under light load. When running at its base frequency, the CPU draws less power and produces less heat.
A compute instance's guest environment reflects the base frequency, regardless of what frequency the CPU is actually running at.
All-core turbo frequency: The frequency at which each CPU typically runs when all cores in the socket are not idle at the same time. Different workloads place different demands on a system's CPU. Boost technologies address this difference and help processes adapt to the workload demands by increasing the CPU's frequency.
- Most compute instances get the all-core turbo frequency, even if only the base frequency is advertised to the guest environment.
- Ampere Altra Arm processors can provide more predictable performance because the frequency for Arm processors is always the all-core turbo frequency.
- C4 VMs are able to
run at all-core-max turbo frequency by setting the
AdvancedMachineFeature
field to
ALL_CORE_MAX. If this field is unset, the VM runs at the default setting, which is unrestricted frequency.
Max turbo frequency: The frequency a CPU targets when stressed by a demanding application like a video game or design modeling application. It's the maximum single-core frequency that a CPU achieves without overclocking.
Processor power management technologies: Intel processors support multiple technologies to optimize the power consumption. These technologies are divided into two categories, or states:
- C-states are states when the CPU has reduced or turned off selected functions.
- P-states provide a way to scale the frequency and voltage at which the processor runs so as to reduce the power consumption of the CPU.
All C4 machine types, and certain C2 (30, 60 vCPUs), C2D (56, 112 vCPUs) and M2 (208, 416 vCPUs) machine types support instance-provided C-state hints by way of the
MWAITinstruction.Compute Engine instances don't provide any facilities for customer control of P-states.
CPU features
Chip manufacturers add advanced technologies for computations, graphics, virtualization, and memory management to the CPUs they produce. Google Cloud supports the use of some of these advanced features with Compute Engine.
Advanced Matrix Extensions (AMX)
Intel AMX is a new instruction set architecture (ISA) extension designed to accelerate artificial intelligence (AI) and machine learning (ML) workloads. AMX introduces new instructions that can be used to perform matrix multiplication and convolution operations, which are two of the most common operations in AI and ML.
AMX is supported on Intel Xeon 5th generation processors (code named Emerald Rapids), which powers the C4 general purpose VM series, as well as Intel Xeon 4th generation processors (code named Sapphire Rapids), which powers the A3 accelerator-optimized and C3 general purpose VMs. All C4 and C3 VM machine types support AMX instruction sets.
AMX introduces 2-dimensional registers called tiles upon which accelerators can perform operations. AMX is intended as an extensible architecture. The first accelerator implemented is called tile matrix multiply unit (TMUL). Each CPU core of the Sapphire Rapids processor has an independent AMX TMUL unit.
More technical details about Intel AMX can be found at Intel AMX support in 5.16. Intel offers a tutorial on AMX at Code Sample: Intel® Advanced Matrix Extensions (Intel® AMX) - Intrinsics Functions.
Requirements for using AMX
Intel AMX instructions have certain minimum software requirements such as:
- For custom images, AMX is supported with Linux kernel version 5.16 or later.
- Compute Engine offers support for AMX in the following
public images:
- CentOS Stream 8 or later
- Container-Optimized OS 109 LTS or later
- RHEL 8 (latest build) or later
- Rocky Linux 8 (latest build) or later
- Ubuntu 22.04 or later
- Windows Server 2022 or later
- Tensorflow 2.9.1 or greater
- Intel extension for Intel® Optimization for PyTorch
For regional availability of C4 and C3 VMs, see Available regions and zones and filter the table to show only C4 or C3 machine types.
CPU features available to bare metal instances
In addition to offering all the raw compute resources of the server, bare metal instances that run on 4th generation Intel Xeon Scalable Processors can use several on board, function-specific accelerators and offloads:
- Intel-QAT: Intel QuickAssist Technology (Intel QAT) accelerates compression, encryption, and decryption
- Intel-DLB: Intel Dynamic Load Balancer (Intel DLB) helps to speed up data queues
- Intel IAA: Intel In-Memory Analytics Accelerator (Intel IAA) improves query processing performance.
- Intel DSA: Intel Data Streaming Accelerator (Intel DSA) helps to copy and move data faster.
Confidential Computing
To protect your data while it's in use, CPU platforms that support Confidential Computing technologies can be used to create Confidential VM instances.
To learn more about the requirements for creating a Confidential VM instance, see Supported configurations.
What's next
- Learn more about Machine families.
- Learn more about Virtual machine instances.
- Learn more about Images.
- Learn how to Specify a minimum CPU platform.
Try it for yourself
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