You shouldnt have to switch signatures off
The premium members can find a thread in the premium forum about the limits of signature pics. (600 x 225 pixels) If you see one that's bigger, please report a post and tell us about it, we can't check/see everyone's signature
Also if you find a gif that's slowing things down too much, please report so we can look into it.
The problem could be that the forum server only checks the resolution
of the animated GIF.
So the servers checks the limit of 600 x 225 limiting the file-size to 20k or something. But it doesn't check for animated gifs. So if the gif has 1000 frames with 600 x 225 size that's 20MB!!! Clearly a loophole there.
After the picture is loaded once on most desktop systems it will resolve because it stored in the temporary internet files
although it still slows down slower PCs because of the huge size.
However, if the PC or mobile device has a medium/slow net connection there will be huge delay the first time the page loads, or every time if the device doesn't have large internet cache (temporary internet files) or isn't properly configured.
Apart from the problems for users this may also kill server
performance. I wouldn't be surprised if the recent problems with the MTF server is related to this loophole. I mean repeatedly having to send 20000k instead of 200k to load a forum page is some difference for a server!