The new forums' rich-text editor hogs the CPU when using IE 8 on Vista. The following causes it to consume 40% of a dual-core 1.8 GHz CPU (80% of a single processor):
1. Reboot and open a new IE 8 window.
2. Go to a forum and open 5 messages in tabs.
3. Click on the first message tab.
4. Reply to the message.
5. Click the mouse on the editor's text box (where you type the body of a reply).
6. Click on the other 4 message tabs in turn.
7. Click back on the tab with the message reply being edited.
If I open a new IE 8 window and repeat with another forum, about 80% of my CPU is being used.
This doesn't happen with Firefox on the same machine or IE 7 on another XP machine.
It's not reasonable to say "use Firefox", because most users of many products (e.g. Photoshop Elements) are on IE, and Windows auto-update is gradually upgrading users to IE 8 over the next couple of months.
Just to let you know I agree with you... I haven't really done any testing, but I do keep a copy of the Windows Task Manager open most of the time... and this forum software causes a huge resource hit. Doesn't matter what kind of machine or browser or anything. A beefier machine is less affected then an older or bare bones one with limited resources, but it's still too much of a hit.