Choosing the right machine shape for your AlloyDB for PostgreSQL cluster is critical
for getting the best performance and cost efficiency for your database workload.
This document helps you choose the right machine type by describing the
AlloyDB machine series, their intended use cases, and how Google
determines where to launch the machine series.

Having a diverse set of machine types lets you customize your
AlloyDB instance for your use case, whether you have a massive
dataset that benefits from a huge cache, or you have a high-concurrency
transactional workload that benefits from the highest number of cores. This
flexibility ensures that AlloyDB can support everything from
massive, very large database workloads to standard, mission-critical
applications.

## Machine series overview

AlloyDB offers the following machine series, each built on a
different underlying Google Cloud compute platform and optimized for specific
performance characteristics.

| **Machine series** | **Core platform and CPU** | **Primary workload focus** | **Key performance differentiator** |
|---|---|---|---|
| N2 | 3rd Generation Intel x86 processors (Ice Lake) | Legacy, general purpose | Available in all regions. |
| C4A | Google Axion ARM | Price performance, high throughput | Provides the best transaction throughput for cache-fitting workloads. |
| C4 | 6th generation Intel x86 processors (Granite Rapids) with Titanium SSD. | Low latency or very large database workloads | Provides the largest machine options with local SSDs for the fastest cache. |
| Z3 | 4th generation Intel x86 processors (Sapphire Rapids) with Titanium SSD | Large working dataset, storage intensive | Allows caching of more data per vCPU; optimized for storage-dense, I/O-intensive workloads |

## Machine series availability for AlloyDB clusters

You can choose one of the following machine series:

- **N2**: this machine series provides a balanced price-to-performance ratio for a variety of AlloyDB workloads.
- **C4A Axion-based**: this machine series provides optimized price-performance and delivers predictable high performance for high demand AlloyDB workloads.
- **C4**: this machine series provides excellent performance, and the largest vertical scale in AlloyDB.
- **Z3**: this machine series is optimized for storage-dense, I/O-intensive workloads.

### N2

The following machine types are available for instances for the N2 machine
series. For more information, see [N2 machine series](https://docs.cloud.google.com/compute/docs/general-purpose-machines#n2_series).

<br />

| **Machine type** | **vCPUs** | **Memory (GB)** |
|---|---|---|
| ` n2-highmem-2 ` | 2 | 16 GB RAM |
| ` n2-highmem-4 ` | 4 | 32 GB RAM |
| ` n2-highmem-8 ` | 8 | 64 GB RAM |
| ` n2-highmem-16 ` | 16 | 128 GB RAM |
| ` n2-highmem-32 ` | 32 | 256 GB RAM |
| ` n2-highmem-64 ` | 64 | 512 GB RAM |
| ` n2-highmem-96 ` | 96 | 768 GB RAM |
| ` n2-highmem-128 ` | 128 | 864 GB RAM |

<br />

### C4A Axion-based

The following machine types are available for instances for the C4A Axion-based
machine series. For more information, see [C4A machine series](https://docs.cloud.google.com/compute/docs/general-purpose-machines#c4a_series).

<br />

| **Machine type** | **vCPUs** | **Memory (GB)** |
|---|---|---|
| ` c4a-highmem-1 ` | 1 | 8 GB RAM |
| ` c4a-highmem-2-lssd ` | 2 | 16 GB RAM |
| ` c4a-highmem-4-lssd ` | 4 | 32 GB RAM |
| ` c4a-highmem-8-lssd ` | 8 | 64 GB RAM |
| ` c4a-highmem-16-lssd ` | 16 | 128 GB RAM |
| ` c4a-highmem-32-lssd ` | 32 | 256 GB RAM |
| ` c4a-highmem-48-lssd ` | 48 | 384 GB RAM |
| ` c4a-highmem-64-lssd ` | 64 | 512 GB RAM |
| ` c4a-highmem-72-lssd ` | 72 | 576 GB RAM |

<br />

### C4

The following machine types are available for instances for the C4 machine
series. For more information, see [C4 machine series](https://docs.cloud.google.com/compute/docs/general-purpose-machines#c4_series).

<br />

| **Machine type** | **vCPUs** | **Memory (GB)** |
|---|---|---|
| ` c4-highmem-4-lssd ` | 4 | 32 GB RAM |
| ` c4-highmem-8-lssd ` | 8 | 64 GB RAM |
| ` c4-highmem-16-lssd ` | 16 | 128 GB RAM |
| ` c4-highmem-24-lssd ` | 24 | 192 GB RAM |
| ` c4-highmem-32-lssd ` | 32 | 256 GB RAM |
| ` c4-highmem-48-lssd ` | 48 | 384 GB RAM |
| ` c4-highmem-96-lssd ` | 96 | 768 GB RAM |
| ` c4-highmem-144-lssd ` | 144 | 1152 GB RAM |
| ` c4-highmem-192-lssd ` | 192 | 1536 GB RAM |
| ` c4-highmem-288-lssd ` | 288 | 2304 GB RAM |

<br />

### Z3 standardlssd

The following machine types are available for instances for the Z3 machine
series. For more information, see [Z3 machine series](https://docs.cloud.google.com/compute/docs/storage-optimized-machines#z3-standardlssd).

<br />

| **Machine type** | **vCPUs** | **Memory (GB)** |
|---|---|---|
| ` z3-highmem-14-standardlssd ` | 14 | 112 GB RAM |
| ` z3-highmem-22-standardlssd ` | 22 | 176 GB RAM |
| ` z3-highmem-44-standardlssd ` | 44 | 352 GB RAM |
| ` z3-highmem-88-standardlssd ` | 88 | 704 GB RAM |

<br />

### Z3 highlssd

The following machine types are available for instances for the Z3 `highlssd`
machine series. For more information, see [Z3 machine series](https://docs.cloud.google.com/compute/docs/storage-optimized-machines#z3-highlssd).

<br />

| **Machine type** | **vCPUs** | **Memory (GB)** |
|---|---|---|
| ` z3-highmem-8-highlssd ` | 8 | 64 GB RAM |
| ` z3-highmem-16-highlssd ` | 16 | 128 GB RAM |
| ` z3-highmem-22-highlssd ` | 22 | 176 GB RAM |
| ` z3-highmem-32-highlssd ` | 32 | 256 GB RAM |
| ` z3-highmem-44-highlssd ` | 44 | 352 GB RAM |

<br />

## Regional availability methodology

AlloyDB helps you deploy and scale
high-availability database solutions wherever you need them.

AlloyDB requires high availability (HA) to protect your
mission-critical data. This means that to launch any machine series in a given
Google Cloud region, the underlying Compute Engine platform supporting
that machine series must be available in all three zones within that region.
This requirement ensures that when you choose a region for your
AlloyDB cluster, the necessary infrastructure is redundant and
geographically distributed in that area, which provides the failover
capabilities that you need.

### Machine series regional deployments

Use the following table to learn where you can find AlloyDB
platforms. N2 offers General Availability, and C4A Axion-based offers the widest
modern coverage.

| **Region** | **Machine series** ||||
| **Region** | N2 | C4A | C4 | Z3 |
|---|---|---|---|---|
| ` africa-south1 ` | ✅ | -- | -- | -- |
| ` asia-east1 ` | ✅ | ✅ | ✅ | -- |
| ` asia-east2 ` | ✅ | -- | -- | -- |
| ` asia-northeast1 ` | ✅ | -- | ✅ | ✅ |
| ` asia-northeast2 ` | ✅ | -- | -- |
| ` asia-northeast3 ` | ✅ | -- | ✅ | -- |
| ` asia-south1 ` | ✅ | -- | -- | -- |
| ` asia-south2 ` | ✅ | -- | ✅ | -- |
| ` asia-southeast1 ` | ✅ | ✅ | ✅ | ✅ |
| ` asia-southeast2 ` | ✅ | -- | -- | -- |
| ` asia-southeast3 ` | ✅ | -- | -- | -- |
| ` australia-southeast1 ` | ✅ | -- | -- | -- |
| ` australia-southeast2 ` | ✅ | -- | -- | -- |
| ` europe-central2 ` | ✅ | -- | -- | -- |
| ` europe-southwest1 ` | ✅ | -- | -- | -- |
| ` europe-north1 ` | ✅ | -- | -- | -- |
| ` europe-north2 ` | ✅ | -- | -- | -- |
| ` europe-west1 ` | ✅ | ✅ | ✅ | ✅ |
| ` europe-west2 ` | ✅ | ✅ | ✅ | ✅ |
| ` europe-west3 ` | ✅ | ✅ | -- | ✅ |
| ` europe-west4 ` | ✅ | ✅ | ✅ | ✅ |
| ` europe-west6 ` | ✅ | -- | -- | -- |
| ` europe-west8 ` | ✅ | -- | -- | -- |
| ` europe-west9 ` | ✅ | -- | -- | -- |
| ` europe-west10 ` | ✅ | -- | -- | -- |
| ` europe-west12 ` | ✅ | -- | -- | -- |
| ` me-central1 ` | ✅ | -- | -- | -- |
| ` me-central2 ` | ✅ | -- | -- | -- |
| ` me-west1 ` | ✅ | -- | -- | -- |
| ` northamerica-northeast1 ` | ✅ | -- | -- | -- |
| ` northamerica-northeast2 ` | ✅ | -- | ✅ | -- |
| ` northamerica-south1 ` | ✅ | -- | ✅ | ✅ |
| ` southamerica-east1 ` | ✅ | -- | -- | -- |
| ` southamerica-west1 ` | ✅ | -- | -- | -- |
| ` us-central1 ` | ✅ | ✅ | -- | ✅ |
| ` us-east1 ` | ✅ | ✅ | -- | ✅ |
| ` us-east4 ` | ✅ | ✅ | ✅ | ✅ |
| ` us-east5 ` | ✅ | -- | ✅ | ✅ |
| ` us-east7 ` | ✅ | -- | -- | -- |
| ` us-south1 ` | ✅ | -- | -- | ✅ |
| ` us-west1 ` | ✅ | -- | ✅ | ✅ |
| ` us-west2 ` | ✅ | -- | -- | -- |
| ` us-west3 ` | ✅ | -- | ✅ | -- |
| ` us-west4 ` | ✅ | -- | ✅ | -- |

## What's next

- [Create a cluster and its primary instance](https://docs.cloud.google.com/alloydb/docs/cluster-create#procedure).
- Learn about [AlloyDB locations](https://docs.cloud.google.com/alloydb/docs/locations).