[OpenLayers-Dev] OpenLayers performance

[Christopher Schmidt]

On Mon, Apr 07, 2008 at 09:35:50PM +0200, tomas.novotny at tmapy.cz wrote:
> The link to OL example Guillaume posted is also the case I wrote about.
> Let's try it (http://www.openlayers.org/dev/examples/fullScreen.html).
> Please switch off overlay for fair-play and zoom in the map. Then make a
> few large circles with map using mouse. Try the same with GM. And don't
> try to tell me you have the same feeling (at least in FF 2 and IE7).

Well, I hate to be the bearer of bad news, but on my browser on my
computer, they feel about the same. 

This is backed up, to some extent, by empirical evidence: using a
stopwatch, I dragged each map around in circles, clockwise, for 5
seconds, with the Firebug profiler turned on for each. 

OpenLayers: 944.26ms, 57342 calls
Google Maps: 820.147ms, 44818 calls

So, it appears that OpenLayers could be said, based on the empirical
evidence on my browser, to be about 15% slower than Google Maps: given
the limited scope of the specific test here, I would say that's not
really a big enough difference to complain about.

Interestingly enough, this is apparently a significant change from 2.5:

OpenLayers 2.5: 1469.714ms, 138497 calls

So, we've gained a 35% performance improvement without even trying. Not
bad.

> And I've made lot of such tests with same result.
> I have absolutely nothing personal against OL, I really like them from
> many points of view. I also understand and agree with Christopher when he
> talks about freedom of influencing OL code. But if I try to solve that
> panning problem I would do so significant change that I would be really
> worried about the rest of the code. 

Well, without understanding what is behaving slowly for you, it's hard
for anyone to fix it, but as I said, there is no intention to be slow,
and I don't see any serious evidence to indicate that OL is any worse in
this case than any other mapping API on my platform of choice.

Regards,
-- 
Christopher Schmidt
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