Networking :: Sysctl.conf Settings For Best Internet Connection Speeds?

Last week I attempted to get "up to speed" with my Comcast cable connection... Ubuntu 9.10, Dell Vostro 400 desktop, Firefox 3.6.13... Comcast says I should have 12 Mbps connection... if I get 1.0 Mbps, I'm doing good... they just tested everything, and said everything is fine on their end. They use [URL] and connects to a server in Chicago, 60 miles away. That gets fantastic speeds, and it's a durn shame the internet doesn't store all its files there!! I use [URL] for my tests, and it uses a server in Dallas TX.

I go to my girlfriends house, and her AT&T DSL line has d/l speeds of 4.5 Mbps or better!!! She's running XP Pro on a Dell machine. So, started digging on the web and thru the forums, and found this:

[URL]

But, like ALL too many things, it's dated... it's from 2008... I've set my settings to what is there, and disabled ipv6 in Firefox. Hey, now, I'm sometimes up to 1.4 Mbps!! Also found this, but no date...

[URL]

Reading forums, I see that folks have said there is a network connection problem with 9.10... and then I see that others are saying the same thing about 10.04 and 10.10!! I have 10.10 on my laptop and had to fight to get its Atheos card to be recognized. Running some tests [URL] gives me weird results: Download 2.64 Mbps, Upload 4.12 Mbps. NOT what it should be. Similar results from testmy.net.

Dunno exactly what info is needed... Speedguide.net gives me results below, but I've tried changing numbers (says my RWIN is low) and nothing changes:

--------------------------------
TCP options string = 020405b40402080adf1dca100000000001030306
MTU = 1500
MTU is fully optimized for broadband.

[code]....

So, today, find, once again, that I'm d'ling in the range of 90/KB/s (719 Kbps)... disgustingly slow. I go on my HP laptop and run the test, and it says 1.6 Mbps. So, desktop directly connected to router is not even 1 Mbps, and wireless connection is faster? Neither of which is close to what I should be getting...