Zimbra VERY SLOW. How to improve performance?

[Bill Brock]

I have two clients running this processor with 512MB of RAM and windows 2000 that runs the AJAX web client just fine running FF3 with 100Mb NIC. My home computer was, up until 2 weeks ago, running the 3000+ Athlon across the Internet and it ran just fine. As a matter of fact, one of my Zimbra servers runs on a 3000+ Athlon. These Barton core processors have plenty of power to run the AJAX client.

Windows 95 and 98 era machines are probably running considerably less hardware I would think.

Have you checked all machines for viruses and/or trojans? These can kill a browsers performance quicker than anything.

[Klug]

As long as the graphic card is OK, there's no problem with an old CPU to run the AJAX client.

The kid's computer at home is an Ahtlon 2400XP+ and it runs the AJAX client flawlessly. Really. But the graphic card is a GeForce MX2...

It's old (2001 or stg) but much better than the some cheap lame Via integrated graphic cards you get in some (newer) motherboard (2003 for the one I'm talking about).

2800XP+ with 2GB RAM and Via IGP = painfully slow, nearly unusable (more than 5 seconds to open a reply window)
2400XP+ with 1 GB RAM and GeForce2 MX = very very usable, no issue

Both running under XP (just reinstalled).

[dvdias]

I would to say that AJAX was discarded in the first test, and selected the default html for all users. Even in HTML, the slowly is great. Remembering that the logon, and many tasks such as switch the tabs, click on the folders are fast, but tasks like editing email, type the destination address, move e-mail folder is very slow.
The old machine with windows 95, 98 and 2000 was chosen thunderbird + lightning. The rest of the machine is running Windows XP and Windows Vista.
The capacity of the server hardware is not consume many resources. I can download files by ssh in high performance, even if the ethernet is beyond 100Mbps when they are all slow in the Zimbra.
I still think I can improve performance by increasing the number of simultaneous HTML access, but I do not know where setup.