Rewrite Gitaly recommendations section

doc/administration/reference_architectures/3k_users.md

@@ -967,17 +967,21 @@ Refer to your preferred Load Balancer's documentation for further guidance.
 ## Configure Gitaly
 
 Deploying Gitaly in its own server can benefit GitLab installations that are
-larger than a single machine. Gitaly node requirements are dependent on data,
-specifically the number of projects and their sizes. It's recommended that each
-Gitaly node store no more than 5TB of data. Your 2K setup may require one or more
-nodes depending on your repository storage requirements.
-
-We strongly recommend that all Gitaly nodes should be set up with SSD disks with a throughput of at least
-8,000 IOPS for read operations and 2,000 IOPS for write, as Gitaly has heavy I/O.
-These IOPS values are recommended only as a starter as with time they may be
-adjusted higher or lower depending on the scale of your environment's workload.
-If you're running the environment on a Cloud provider
-you may need to refer to their documentation on how configure IOPS correctly.
+larger than a single machine.
+
+The Gitaly node requirements are dependent on customer data, specifically the number of
+projects and their repository sizes. Two nodes are recommended as an absolute minimum.
+Each Gitaly node should store no more than 5TB of data and have the number of
+[`gitaly-ruby` workers](../gitaly/index.md#gitaly-ruby) set to 20% of available CPUs.
+Additional nodes should be considered in conjunction with a review of expected
+data size and spread based on the recommendations above.
+
+It is also strongly recommended that all Gitaly nodes be set up with SSD disks with
+a throughput of at least 8,000 IOPS for read operations and 2,000 IOPS for write,
+as Gitaly has heavy I/O. These IOPS values are recommended only as a starter as with
+time they may be adjusted higher or lower depending on the scale of your environment's workload.
+If you're running the environment on a Cloud provider, you may need to refer to
+their documentation on how to configure IOPS correctly.
 
 Some things to note: