[Yandex Cloud documentation](../../index.md) > [Yandex Managed Service for PostgreSQL](../index.md) > [Concepts](index.md) > Host classes > Active host classes # PostgreSQL host classes The host class determines the computing power allocated for each host in a cluster. When you change the host class for a cluster, all existing hosts change accordingly. The host class determines the available [disk types](storage.md): * **s1**, **s2**, **s3**, **m2**, **m3**, **c3**: `network-ssd`, `network-hdd`, `local-ssd`, `network-ssd-nonreplicated`, `network-ssd-io-m3`. * **b1**, **b2**: `network-ssd`, `network-hdd`. The available storage size does not depend on the host class. For storage limitations, see [Quotas and limits](limits.md). ## Available host classes {#available-flavors} Hosts in Managed Service for PostgreSQL clusters are deployed on Yandex Compute Cloud VMs. You can create these VMs on any platforms Compute Cloud supports. To learn more about the platforms, see [Platforms](../../compute/concepts/vm-platforms.md). The full list of possible host configurations on each platform is provided below. {% note info %} Clusters with hosts residing in the `ru-central1-d` [availability zone](../../overview/concepts/geo-scope.md) do not support: - Intel Broadwell - Local SSD storage if using Intel Cascade Lake {% endnote %} {% note alert %} Starting January 1, 2024, the following host classes are out of service: `b1.nano`, `b1.micro`, `b1.small`, `b2.nano`, `b2.micro`, and `b2.small`. You will not be able to create hosts of these types starting June 20, 2023. {% endnote %} Configuration types: * **s1**, **s2**, **s3**: Standard configurations with a 4:1 RAM GB to vCPU ratio. * **m2**, **m3**: Configurations with an increased RAM GB to vCPU ratio (8:1). These configurations may be useful for clusters with higher cache requirements. * **c3**: Configurations with a reduced RAM GB to vCPU ratio (2:1). These configurations may be useful for clusters with higher processor performance requirements. * **b1**, **b2**: Configurations with a guaranteed vCPU share under 100%. This host class is intended for test load, while the minimum recommended host configuration for production solutions is two vCPUs with a guaranteed share of 100%. {% note info %} Hosts with a guaranteed vCPU share under 50% cannot be used in multi-host clusters. {% endnote %} | Host class name | Number of vCPUs | CPU performance | RAM, GB | Disk
size, GB | |-------------------|----------------|------------------------|---------|----------------------| | **Intel Broadwell** | | b1.medium | 2 | 50% | 4 | 10 – 512 | | s1.micro | 2 | 100% | 8 | 10 – 10,230 | | s1.small | 4 | 100% | 16 | 10 – 10,230 | | s1.medium | 8 | 100% | 32 | 10 – 10,230 | | s1.large | 16 | 100% | 64 | 10 – 10,230 | | s1.xlarge | 32 | 100% | 128 | 10 – 10,230 | | **Intel Cascade Lake** | | b2.medium | 2 | 50% | 4 | 10 – 512 | | m2.micro | 2 | 100% | 16 | 10 – 10,230 | | m2.small | 4 | 100% | 32 | 10 – 10,230 | | m2.medium | 6 | 100% | 48 | 10 – 10,230 | | m2.large | 8 | 100% | 64 | 10 – 10,230 | | m2.xlarge | 12 | 100% | 96 | 10 – 10,230 | | m2.2xlarge | 16 | 100% | 128 | 10 – 10,230 | | m2.3xlarge | 24 | 100% | 192 | 10 – 10,230 | | m2.4xlarge | 32 | 100% | 256 | 10 – 10,230 | | m2.5xlarge | 40 | 100% | 320 | 10 – 10,230 | | m2.6xlarge | 48 | 100% | 384 | 10 – 10,230 | | m2.7xlarge | 56 | 100% | 448 | 10 – 10,230 | | m2.8xlarge | 64 | 100% | 512 | 10 – 10,230 | | s2.micro | 2 | 100% | 8 | 10 – 10,230 | | s2.small | 4 | 100% | 16 | 10 – 10,230 | | s2.medium | 8 | 100% | 32 | 10 – 10,230 | | s2.large | 12 | 100% | 48 | 10 – 10,230 | | s2.xlarge | 16 | 100% | 64 | 10 – 10,230 | | s2.2xlarge | 24 | 100% | 96 | 10 – 10,230 | | s2.3xlarge | 32 | 100% | 128 | 10 – 10,230 | | s2.4xlarge | 40 | 100% | 160 | 10 – 10,230 | | s2.5xlarge | 48 | 100% | 192 | 10 – 10,230 | | s2.6xlarge | 64 | 100% | 256 | 10 – 10,230 | | **Intel Ice Lake** | | s3-c2-m8 | 2 | 100% | 8 | 10 – 10,230 | | s3-c4-m16 | 4 | 100% | 16 | 10 – 10,230 | | s3-c8-m32 | 8 | 100% | 32 | 10 – 10,230 | | s3-c12-m48 | 12 | 100% | 48 | 10 – 10,230 | | s3-c16-m64 | 16 | 100% | 64 | 10 – 10,230 | | s3-c24-m96 | 24 | 100% | 96 | 10 – 10,230 | | s3-c32-m128 | 32 | 100% | 128 | 10 – 10,230 | | s3-c40-m160 | 40 | 100% | 160 | 10 – 10,230 | | s3-c48-m192 | 48 | 100% | 192 | 10 – 10,230 | | s3-c64-m256 | 64 | 100% | 256 | 10 – 10,230 | | s3-c80-m320 | 80 | 100% | 320 | 10 – 10,230 | | s3-c96-m576 | 96 | 100% | 576 | 10 – 10,230 | | m3-c2-m16 | 2 | 100% | 16 | 10 – 10,230 | | m3-c4-m32 | 4 | 100% | 32 | 10 – 10,230 | | m3-c6-m48 | 6 | 100% | 48 | 10 – 10,230 | | m3-c8-m64 | 8 | 100% | 64 | 10 – 10,230 | | m3-c12-m96 | 12 | 100% | 96 | 10 – 10,230 | | m3-c16-m128 | 16 | 100% | 128 | 10 – 10,230 | | m3-c24-m192 | 24 | 100% | 192 | 10 – 10,230 | | m3-c32-m256 | 32 | 100% | 256 | 10 – 10,230 | | m3-c40-m320 | 40 | 100% | 320 | 10 – 10,230 | | m3-c48-m384 | 48 | 100% | 384 | 10 – 10,230 | | m3-c56-m448 | 56 | 100% | 448 | 10 – 10,230 | | m3-c64-m512 | 64 | 100% | 512 | 10 – 10,230 | | m3-c80-m640 | 80 | 100% | 640 | 10 – 10,230 | | c3-c2-m4 | 2 | 100% | 4 | 10 – 10,230 | | c3-c4-m8 | 4 | 100% | 8 | 10 – 10,230 | | c3-c8-m16 | 8 | 100% | 16 | 10 – 10,230 | | c3-c12-m24 | 12 | 100% | 24 | 10 – 10,230 | | c3-c16-m32 | 16 | 100% | 32 | 10 – 10,230 | | c3-c24-m48 | 24 | 100% | 48 | 10 – 10,230 | | c3-c32-m64 | 32 | 100% | 64 | 10 – 10,230 | | c3-c40-m80 | 40 | 100% | 80 | 10 – 10,230 | | c3-c48-m96 | 48 | 100% | 96 | 10 – 10,230 | | c3-c64-m128 | 64 | 100% | 128 | 10 – 10,230 | | c3-c80-m160 | 80 | 100% | 160 | 10 – 10,230 | | c3-c96-m192 | 96 | 100% | 192 | 10 – 10,230 | | **AMD Zen 4** | | s4a-c2-m8 | 2 | 100% | 8 | 10 – 16,368 | | s4a-c4-m16 | 4 | 100% | 16 | 10 – 16,368 | | s4a-c8-m32 | 8 | 100% | 32 | 10 – 16,368 | | s4a-c16-m64 | 16 | 100% | 64 | 10 – 16,368 | | s4a-c32-m128 | 32 | 100% | 128 | 10 – 16,368 | | s4a-c64-m256 | 64 | 100% | 256 | 10 – 16,368 | | s4a-c96-m384 | 96 | 100% | 384 | 10 – 16,368 | | s4a-c128-m512 | 128 | 100% | 512 | 10 – 16,368 | | s4a-c224-m896 | 224 | 100% | 896 | 10 – 16,368 | | s4a-c256-m1024 | 256 | 100% | 1,024 | 10 – 16,368 | | c4a-c2-m4 | 2 | 100% | 4 | 10 – 16,368 | | c4a-c4-m8 | 4 | 100% | 8 | 10 – 16,368 | | c4a-c8-m16 | 8 | 100% | 16 | 10 – 16,368 | | c4a-c16-m32 | 16 | 100% | 32 | 10 – 16,368 | | c4a-c32-m64 | 32 | 100% | 64 | 10 – 16,368 | | c4a-c64-m128 | 64 | 100% | 128 | 10 – 16,368 | | c4a-c96-m192 | 96 | 100% | 192 | 10 – 16,368 | | c4a-c224-m448 | 224 | 100% | 448 | 10 – 16,368 | | c4a-c256-m512 | 256 | 100% | 512 | 10 – 16,368 | | m4a-c2-m16 | 2 | 100% | 16 | 10 – 16,368 | | m4a-c4-m32 | 4 | 100% | 32 | 10 – 16,368 | | m4a-c8-m64 | 8 | 100% | 64 | 10 – 16,368 | | m4a-c16-m128 | 16 | 100% | 128 | 10 – 16,368 | | m4a-c32-m256 | 32 | 100% | 256 | 10 – 16,368 | | m4a-c64-m512 | 64 | 100% | 512 | 10 – 16,368 | | m4a-c96-m768 | 96 | 100% | 768 | 10 – 16,368 | | m4a-c128-m1024 | 128 | 100% | 1,024 | 10 – 16,368 | | m4a-c224-m1792 | 224 | 100% | 1,792 | 10 – 16,368 | | **AMD Zen 4 HighFreq** | | s4af-c2-m8 | 2 | 100% | 8 | 10 – 16,368 | | s4af-c4-m16 | 4 | 100% | 16 | 10 – 16,368 | | s4af-c8-m32 | 8 | 100% | 32 | 10 – 16,368 | | s4af-c16-m64 | 16 | 100% | 64 | 10 – 16,368 | | s4af-c32-m128 | 32 | 100% | 128 | 10 – 16,368 | | s4af-c48-m192 | 48 | 100% | 192 | 10 – 16,368 | | s4af-c80-m320 | 80 | 100% | 320 | 10 – 16,368 | | c4af-c2-m4 | 2 | 100% | 4 | 10 – 16,368 | | c4af-c4-m8 | 4 | 100% | 8 | 10 – 16,368 | | c4af-c8-m16 | 8 | 100% | 16 | 10 – 16,368 | | c4af-c16-m32 | 16 | 100% | 32 | 10 – 16,368 | | c4af-c32-m64 | 32 | 100% | 64 | 10 – 16,368 | | c4af-c48-m96 | 48 | 100% | 96 | 10 – 16,368 | | c4af-c80-m160 | 80 | 100% | 160 | 10 – 16,368 | | m4af-c2-m16 | 2 | 100% | 16 | 10 – 16,368 | | m4af-c4-m32 | 4 | 100% | 32 | 10 – 16,368 | | m4af-c8-m64 | 8 | 100% | 64 | 10 – 16,368 | | m4af-c16-m128 | 16 | 100% | 128 | 10 – 16,368 | | m4af-c32-m256 | 32 | 100% | 256 | 10 – 16,368 | | m4af-c48-m384 | 48 | 100% | 384 | 10 – 16,368 | | m4af-c80-m640 | 80 | 100% | 640 | 10 – 16,368 | #### Useful links {#see-also} * Learn how to [change host class](../operations/update.md#change-resource-preset). * Learn which [settings depend on host class and storage size](settings-list.md#settings-instance-dependent).