optimizing speed under windows 7

[fudgi]

Hey Guys,

ive got a 100 mbit connection @ home now and i can max the line out just fine...when i use larger files... because it takes about 1 or 2 seconds till the line reaches the 100 mbit.. now my question is... is this a hardware issue or is it mayb how my isp works? since i know that other 100 mbit lines dont need that much time... oh btw its cable internet (docsis 3.0)

due to this issue its hard to reach 100 mbit on smaller files (14 mb) which normally should be doable

[MxxCon]

Try enabling "Compound TCP" feature in Win7, see if it'll make any difference. Description and instructions are here http://en.wikipedia.org/wiki/Compound_TCP

Also, you might be reaching 100mbit on smaller files, but bandwidth calculation isn't accurate in such a short time period.

[Yil]

There are a variety of issues here...

First off, TCP/IP has something called slow start. This affects the first bytes to travel across a newly established connection and after dropped packets. Anything after like maybe 100k (or even less) would be at full speed so this is an issue for small files only.

The next thing is SSL negotiation. If you're transferring files encrypted then the handshake data needs to be exchanged before things can start. Couple this with slow start and things take a little bit of time to get really going. This isn't a big deal, but the amortized cost of the setup is smaller the larger the file being transferred so it may make the difference look bigger with wildly different file sizes.

The above is always true, however cable modems have another issue. The bandwidth for uploading data is shared amongst everyone in your immediate area and it has a problem remarkably like old school fat Ethernet. Today you're used to plugging in your computer to a switch which usually has 2 separate channels for sending/receiving which means no collisions, but on a single shared cable line you can't have more than 1 person transmitting at a time. I believe they solve the problem by giving your cable modem a small sliver of time to send a tiny bit of data every milliseconds or so. As soon as you send that first block some smart algorithm starts giving you a larger block of time to send more data next time your window comes up, and then more, etc. Eventually you get the largest piece you're allowed, but the important point here is you don't get that big bandwidth right at the start.

My guess is that the cable modem itself is the biggest issue. The difference between the first 1MB and the 50MB is almost certainly the cable modem, but if you are only looking at total bytes / total time then the setup costs are a larger percentage the smaller the file...

[fudgi]

So i assume that if i had a 100 Mbit ftth line and not Cable Things might look differently? At least the Servers i Know with such Lines manage to get faster Complete speeds than i so, although i assume that if id Run linux things would look different as well.

[Yil]

Now you are talking apples and oranges. Internet routing, router congestion, local bandwidth in use, etc are all big factors. It's nearly impossible to compare 2 different locations unless the traceroutes look nearly the same. When you were talking MB/s for different reasonably sized files to the same location the variables are simpler and you can test changes easily.