# Hierachical Graph Max Number of Nodes/Edges

Hello,
I have a graph with ~ 7000 Edges and ~ 6500 Nodes I tried to create it with dot as an .svg.
But dot is running for ever ( >1h). Is it possible that the Graph is too complex/large ?
What is the maximum size of edges/nodes possible with graphviz?
I know, it's also a question of complexity, but maybe there is some kind of thumbrule.

Thanks!

### Hierachical Graph Max Number

First, except for graphs with few nodes, we assume the graph is sparse, so that number of edges is a modest linear expansion of the number of nodes.

Sfdp and twopi are fast, handling graphs with 100K or even millions of nodes if you can wait a few minutes.

Neato is quadratic in the number of nodes, so you probably want to keep the nodes under a 1000, or a few thousand if you can wait a bit.

Dot is the most complex and the hardest to predict. In the first step, nodes are assigned levels, which is pretty fast. For steps 2 and 3, however, edges crossing multiple levels are broken into chains of length 1 edges. Depending on the graph, this can cause an explosion in the problem size and make crossing reduction and coordinate assignment go on for a long time. As a rough rule, it is best to keep the number of nodes less than 1000.

Using splines in non-dot layouts is cubic, so should only be used for small graphs.

You can get an idea of where the problem is by running the layout with -v.

It should also be noted that since nodes and edges have significant size in Graphviz, it is possible to run out of memory with a sufficiently large graph.

### Best Display for Hierachical Graph

Thanks for those tips, I was wondering the same thing!
However, I have a graph with around 3000 edges, with less than 3000 nodes. When I changed over to sfdp for the file type and created a gif with it, it took about a minute to two minutes. When I opened the gif file all that was there were little dots, nothing I could make sense of.
The GIF file was about 5MB. Which type of output file can handle the most nodes/edges? Also, when I set the size down a bit (420 by 10) the gif file is viewable, but not readable. Everything is smudged. It appears the problem is that it is VERY wide, but not very tall (only about 12 levels) What code could I insert to make it readable. I'm running Linux CentOs, btw.