Question about multithreaded downloads

[jbjb]

This is more of a question out of curiosity than a plee for help, although a remedy for this problem would still be nice.

Anyway, I have a max/max ADSL connection (which, because of distance from DSLAM, ends up about 5.1mbit down and 552kbit/s up) and whenever I download files with FF (or IE if I'm feeling brave) from overseas I get around 1mbit max, usually less, and if it's coming from my own country I get around 2 - 3mbit. However, if I use a download manager with, say, 5 threads, I'll get my full 630ish KB/s.

I'm just curious as to the reason behind this? It's kind of annoying because a lot of sites these days, especially download sites, don't allow multithreaded downloads. We're also getting a lot more horrible "online installers" like Adobe reader which can be painfully slow.

[YARDofSTUF]

Downloading from different locations with download managers helps a lot. If sites limit the speed to 100K you can get that from each site the manager conencts to.

[jbjb]

I'm aware of that, but that's not what I mean. I meant making mutliple connnections, or threads, to a single server to get better speeds.

Also, why it's so slow without doing this, is it something to do with high ADSL latency and the time it takes the ack packets to reach the destination?

[YARDofSTUF]

ADSL shouldnt have much latency. I don't really know, maybe limited speed from the sites per connection? I think if its possible you'll see it more and more the way people abuse the max connection settings in FF with fasterfox or editing the config.

No idea though, I was thinking of something else.

[trogers]

I meant making mutliple connnections, or threads, to a single server to get better speeds.


As YARDofSTUF said, some websites limit the number of connections to one comp due to the common use of software to increase max. no. of connections, though FasterFox extension in FireFox or through the use of multi-threads download mangers.

Due to limits imposed by such websites, you will not be able to get multi-threads on only one site.

[jbjb]

As I said before, I'm well aware of that. All I wanted to know was what caused the slow download when only a single connection was made, but to be clear I'm talking about when the site ISN'T capping the speed.

On a side note, I used TCP optimizer and it's actually boosted local my non multithreaded downloads to about 200%. Local speed test going from about 1.8mbit previously to now 3.8mbit. Overseas downloads have probably increased to about 150%, but I seem to be getting a lot of "waiting for www..." in Firefox after applying the changes.

[trogers]

As I said before, I'm well aware of that. All I wanted to know was what caused the slow download when only a single connection was made, but to be clear I'm talking about when the site ISN'T capping the speed.

On a side note, I used TCP optimizer and it's actually boosted local my non multithreaded downloads to about 200%. Local speed test going from about 1.8mbit previously to now 3.8mbit. Overseas downloads have probably increased to about 150%, but I seem to be getting a lot of "waiting for www..." in Firefox after applying the changes.

If you have a slow download speed through only one thread of a multi-thread download manager, then it could be the internal setting of this software, possibily some QoS settings that allocate separate portions of your bandwidth to the multi-threads.

If you are getting "waiting for www..." in FireFox, change your DefaultTOSValue to 80. Setting at 136 and 160 may face more packet losses. Also, try using Optimized setting with FasterFox rather than the Turbo setting.

[jbjb]

Judging by the answers provided slow downloads with a single thread isn't a commonly encountered problem. It's nothing to do with software because whatever I download with, be it FF, IE or Opera, it's always much slower than my connection will do when using multiple threads.

I don't use Fasterfox, prefetch is baaaad :nod: