Cable Modem In One Case Slower Than DSL

I recently added a cable modem and turned off my wireless DSL. I also ran speedtest.net. The cable modem was from 15-17 times faster than the dsl. I have a direct connection cat 6 cable between the cable modem and my gigabit port. I'm running 32 bit Vista Ultimate. So far so good. However when I use a desktop application to get to the servers for my web sites, my cable speed drops to 1/3 that of the dsl. Something is slowing it down. I don't know if its a protocol between cable and dsl, incorrect Vista settings or something to do with the desktop application. It is not the firewall or antivirus as I removed both of them for a test, and no significant difference was found. The designers of the desktop application (a back office for a shopping cart on the servers) can't figure it out. Cox cable gave up, and the cable forum recommended I come here for possible answers.

Can anyone suggest anything to check or change?

Thank you.

 

Hi Dennis D,

you may want to try changing some of the settings in the network connections properties for the network card.

uncheck QOS packet scheduler
uncheck TCP/IPv6
uncheck both link layer entries

reboot

Techsent

 

Hi Dennis D,

also, maybe try connecting a cat 5 cable instead of 6.

Techsent

 

I tried your suggestion and unchecked the three items. Ran speedtest.net and results were much slower, but that may because of the usage of cable TV on a Sunday afternoon.

Went to my problem application and did not notice a speed improvement.

Appreciate your suggestions, but looks like they did not fix the problem.

For the suggestions of replacing cat 6 wire with cat 5, I do not understand why this might make a difference. I'm willing to try anything, but could you explain a little more why this might be the problem?

Thanks,

Dennis D