I normally use Cable but I have been doing some experimenting with Dial-Up lately and this is what I have come up with.
To start set your connection as dial-up if you set it as anything else you are just messing yourself up.
Second do a speed test the link below will take you to a speed test site. Set your DL speed to just below whatever your results are try 10% below to start.
Do not download more than 1 file at a time it will just take longer to DL the files if you do.
If you want the best search results only search when you are not DL. The reason you are not getting 5 bars is because when you are DL at your maximum connection speed it is using all of your network capabilities to download you do not have anything left for connections.
I have found that it doesn't matter for dial-up if you have 1 bar or 5 for DL speed. But it does matter for search results. If you are not DL you should get 4 or 5 bars.
Simultaneous DL I would not put at more than 2 explained above 1 would be best.
Browsing host does not work very well but the better your connection the better it appears to work.
Hope this helps
http://www.speakeasy.net/speedtest/