[Talk-us] TopOSM Colorado

[Ian Dees]

On Fri, Sep 4, 2009 at 12:44 PM, Lars Ahlzen <lars at ahlzen.com> wrote:

> There's also the size of the data sets. The entire hi-res NHD and NED
> would probably be many, many TB. Unpacking, preparing and indexing that
> data requires plenty of additional disk space as well. One would
> probably have to re-work the scripts to work on smaller areas at a time,
> as well as invest in some sizable drives. The tiles themselves for CO
> are about 12 GB and 20 GB for MA, so I'd need a web host that's willing
> to host a TB or so of images. :)
>

The hi-res NHD data set fits on 4.5 DVDs. They sent me a set of NHD data
last year around this time for free (they're very nice folks!). I was
considering asking nicely for another set, but I was going to try and build
a faster computer to handle it, first.

I don't know about the NED data, but I imagine it would be a similar size
for the US continental area.


> Finally, Colorado alone took the better part of a week on my quad-core
> rendering server. And this excludes all importing and preprocessing of
> the data. Extrapolate for 48 more states..."
>

This sounds like an interesting experiment worth running on Amazon's EC2
cloud. Their x-large machines run at $1/hour, but sure would chomp on this
data quickly!

I would be willing to try (and pay for) it if Lars went through a did an
updated setup doc.

Because the layers are rendered separately, the less-frequently-changing
tiles (like NED and for a while the NHD) could be done once for the entire
country to save on rendering costs.
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