Gif animation slow with big dimensions

[x86freak]

Hi,
I have a question about gif images: why IrfanView has a problem displaying big dimension gifs?
It plays say 320x180 ones just fine, but if u simply resize the gif 2 times - it lags like hell. Other viewers I use don't seem to have a problem displaying big gifs.
I've seen this for a long period and thought that by now that got resolved, but it's v4.25 and lag still exists
It's rather annoying I have to use a different program just for gif files.

Gif test01:

http://img529.imageshack.us/img529/2765/t01.gif

Gif test02:

http://img404.imageshack.us/img404/4194/t02.gif

[Sam_Zen]

I fully agree. It's getting very slow.

[x86freak]

Thank you for replying. Let's just hope the right people consider this a problem worth solving .

[Sam_Zen]

In fact this effect can be monitored by zooming in on the GIF with the plus-key.
Each step will slow down the playback speed.

[x86freak]

I did a little test.
The 1st gif eats about 1-5 of my CPU (Task Manager). If I zoom to the maximum it rises to 10-12 CPU but strangely I get no zoom lag
The 2nd gif however goes to ~30 CPU !!! Whats even more strange - zooming to full 3740% doesn't change CPU consumption like there's a cap on 30% or something.
CPU: AMD Athlon 64 X2 5000+.