> ## Documentation Index
> Fetch the complete documentation index at: https://docs.goldsky.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Performance benchmark

> A test of Mirror's write speeds into a ClickHouse database.

## Overview

As a quick test of Mirror's write performance, we ran a pipeline of each size backfilling Ethereum blocks data (\~18.5M rows as of October 23, 2023) with an [unmodified schema](/reference/schema/EVM-schemas#raw-blocks).

This test was performed on a 720 GiB RAM, 180 vCPU [ClickHouse Cloud](https://clickhouse.com/) instance to ensure that non-pipeline factors (eg. disk IO, available memory, CPU cores) do not act as a bottleneck.

Each test was run on a completely clean instance (ie. no existing tables) with no other queries or commands running on the database.

## Results

| Pipeline size | Peak (rows/m) | Time to backfill |
| ------------- | ------------- | ---------------- |
| S             | 350,000       | 53min            |
| M             | 950,000       | 20min            |
| L             | 2,100,000     | 9min             |
| XL            | 3,500,000     | \~5min           |
| XXL           | 6,300,000     | 3min             |