Extremely Variable Rendering Times

I have a local global OSM server up and it is running, but the rendering speeds vary drastically. An example:

DEBUG: DONE TILE english 9 216-223 144-151 in 32.009 seconds

DONE TILE english 16 74992-74999 11408-11415 in 304.705 seconds

I have run the indexes from here: OSM PostGIS Tuning and it seems to not have made much of a difference. I would say for Z16 the average render time is about 190 seconds. This is sitting on the following hardware:

• Intel i9-10850K (20 Core)
• 128GB DDR4
• OS is sitting on 1TB NVME
• OSM Database is sitting on 4TB NVME

Here are my postgres settings (this all sits on postgres 12) some taken from here: osm2pgsql manual:

• max_connections = 300

• shared_buffers = 16GB

• work_mem = 10GB

• maintenance_work_mem = 10GB

• autovacuum = on

• effective_io_concurrency = 300

• wal_level = minimal

• fsync = off

• synchronous_commit = off

• max_wal_size = 10GB

• min_wal_size = 80MB

• checkpoint_completion_target = 0.9

• max_wal_senders = 0

• random_page_cost = 1.1

• effective_cache_size = 70GB