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For slim mode, how much RAM is ideal for an import?

In non-slim mode, how much is likely to be needed in all?

Obviously, the more data in a .osm file, the more memory that will be needed, so what I'm looking for is an answer along the lines of, "xMB per thousand nodes, yMB per thousand ways" or "such and such based on the highest node ID".

asked 22 Jun '11, 19:21

asciiphil's gravatar image

accept rate: 0%

For slim mode you can use as much or as little RAM as you like, but I wouldn't try anything under 1Gb. For a planet file you will find more RAM makes everything go faster up to at least 24GB if not further. The RAM functions as a cache for the nodes data that's repeatedly needed for constructing the ways and relations - if the node isn't in RAM it'll be fetched from disk with is much slower.

For non-slim mode, you have hard limits since there is no intermediate disk store for the nodes. A full planet import in non-slim mode currently requires about 40 Gb of RAM.

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answered 23 Jun '11, 18:51

Andy%20Allan's gravatar image

Andy Allan
accept rate: 28%

edited 27 Jun '11, 05:43

emj's gravatar image


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question asked: 22 Jun '11, 19:21

question was seen: 7,519 times

last updated: 27 Jun '11, 05:43

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