I am serving vector tiles using [TileStache](https://github.com/TileStache/TileStache), I have everything set up like I want. My data is stored in **Postgres** and I am using the [VecTiles](http://tilestache.org/doc/TileStache.Goodies.VecTiles.server.html#Provider) provider to serve **GeoJSON** tiles.

I want to cache all my tiles to make the tiles serve faster. I am using [tilestache-seed.py](https://github.com/TileStache/TileStache/blob/master/scripts/tilestache-seed.py) to seed my cache. I am running **tilestache-seed** on several machines. Tilestache-seed worked really well uptill zoom level 13, but after that it is taking way too long to cache the tiles. Just for Zoom Level 16 I have 5023772 tiles to cache, and I am only getting 100k-200k tiles per day on each machine. 

How can I make my **tiles cache faster**? Is there a way to fine tune [tilestache-seed.py](https://github.com/TileStache/TileStache/blob/master/scripts/tilestache-seed.py) and make it seed faster?

*PS: I have looked into spatial indexes but I'm not really sure how to go about creating indexes and if that will make a significant impact on the caching speed, by my understanding Postgres automatically creates spatial indexes when shapefiles are imported via postgis shapefile and dbf loader plugin.*

***Update:** I have tried building spatial indexes on my tables (on the geometry column and the columns used for filtering data through the where clause) and I still haven't seen a significant increase in tiling speed. At this rate only Zoom 17 will take me a month and this time will only increase exponentially as I move towards Zoom 21*

***Hardware Info** I am running the caching processes on 8 different PCs, one of which is an i7 with 32gb ram and another is an i3 with 4gb ram but they both give me almost the same caching speed,(approximately 100k tiles per day)*