This is the amount of processed data after decompression. The amount of compressed data is less. You can press whitespace during the query run to see the detailed metrics.

    ReadBufferFromS3Bytes                     8.95 GB

The amount of compressed data read from S3 is 8.95 GB. Note: it sounds quite large, interesting why compression is less than 2x on this dataset. Most likely, it uses just lz4.

I recommend trying it because it works everywhere. You can run ClickHouse on your laptop, on a VM, or even in Cloudshell in AWS.