To change the DataRate to 8, or not to

Here are the details on DataRate.txt from the everquestlive knowledge base:

Here is the solution: EverQuest: How to edit Datarate file?
Enter into the Everquest Folder(the default location is "c:\program files\everquest\" or "c:\program files\sony\everquest\") and locate the file named "Datarate.txt". Open this file and change the text to read "9.0" instead of "5.0". Save the file and try EverQuest again.

Raising the datarate will cause the game to send your computer larger data packets. Some connections will perform better with larger packet sizes. Many users have also commented that increasing packet size decreases zoning time.

If you notice that the problem is not resolved using the value of "9.0", then try using the value "3.0".

Some users tend to have packet loss on their connections for a variety of reasons. Lowering the EverQuest "Datarate" value will reduce the size of the data packets, allowing more "good" data to come across during a packet loss situation.

Do not use any values lower than "3.0" or higher than "9.0", as the results will be unpredictable, and may cause further problems.

If these recommendations do not resolve your problem please change the datarate value back to "5.0" ...

Basically higher datarate = bigger packets = better performance, unless you have packet loss (usually noisy or congested lines between your PC and the EQ servers), in which case the smaller the packets, the better chance they have of getting through to the server. Well, that is my understanding of what the Sony KB post is saying , and my day job is data networking and it makes sense to me.