Bret, Richard, Jason, Thank you all for your comments and suggestions. What I had been doing -- using GD to create the image with db data in one file, then calling this file from <IMG SRC="make_the _picture_in_here.php"> in another page, seems to have been the culprit in regards to the latency issue. Of note is that this is an intranet app, traffic is not so heavy, and the netadmin has already said that he didn't think the network was the issue. However at a previous building, the app worked just fine, which was the only reason that I even pursued the approach I was taking. Also, Mozilla (Gecko...?) is almost perfectly stable as opposed to IE, which just doesn't cut it at all. I had concerns similar to Richard about reading and writing to the same file at the same time. So, for the time being, we are going to live with a 5 second delay in data availability, i.e., use html to display the latest image file at the top of the page, then jump into php and overwrite the file with new data at the bottom of the page, then wait 5 seconds for the page to refresh with the latest image. The idea of using pre-made, colored flags, handled within the code, sounds very reasonable, and if problems persist, I think this approach will be tried next. There are only 3 colors for flag states, red - yellow - green, and these cover 24 Neutron monitors, so not too time consuming to implement. But other data from the db get displayed also, so it still seems best to create one image with all the data for the entire page, assuredly large at about 1200 X 800 pixels. Is it possible to limit the bit-depth or reduce the file size of a PNG image ? I haven't found anything in the manual about this as yet. David