Memory in Vista

[LDWhite68]

Following on my other posts, I've been watching more carefully Task Manager when running Topofusion. It appears that TF is using a lot more resources in Vista than it does in XP. When I load a 3 MB PNG file of a 7.5' USGS quad into User Maps, Task Manager shows an increase in memory use of about 400 MB. Doing the same on my office XP desktop, it only goes up by about 160 MB (which still seems like a lot to me). I'm pretty much limited then to only having 2 quads open at a time in Vista, so that I can't really get a seamless view in the vicinity of quad corners. To make matters worse, if I disable the user map in Vista, the memory does not (ever?) decrease. In XP it quickly comes back down to what it was before.

I wonder if I have any different configuration settings in the two installations that might partly account for the huge differences. I have not done as clear of comparison yet for gpx files. Any insights?

[ScottMorris]

Increase of 400MB?  Wow, that is outrageous.  In general it should be higher than the size of the (compressed file), but not by that much.  What are the dimensions of the image?

Even 160 mb is way too much.  I just loaded up a 3000x3000 user map and the memory usage went up about 50 mb. 

I can give it a try on my Vista machine tomorrow and get back to you.  I will see if there isn't something strange going on.  Thanks for the post.

[ScottMorris]

Update - dug into the code and the DXT1 compression flag was off as a result of chasing a problem that a user had with one of his user maps.  That accounts for even my large memory usage.  It's now down to ~10mb for the 3000x3000 file, as it should be.

It does make the load time on the user maps a bit longer, though.