Simple and quick question?

Fighting Irish

Does uploading something affect your download speed?

Karoma

What type of broadband connection..?

kaizersoze

Fighting Irish wrote:

Does uploading something affect your download speed?

Simple answer, yes, if your uploading flat out to the full capacity of your upstream.

Fighting Irish

BT+

So if i'm uploading say a picture to an image host and i download something at the same time my download won't be as quick as usual

Karoma

Short answer is Yes.

ADSL:

http://www.internode.on.net/adsl/faq/padsl-troubleshooting.htm#ts13 wrote:

It is also important to appreciate that concurrent uploads have a very significant effect on your available download speed. This effect is especially pronounced with ADSL services (compared to other, symmetric forms of Internet link).

ADSL services are more significantly affected because all data transfers need to send data in both directions in order to work properly. When you are 'downloading' something, there is a stream of 'ACK' (or Acknowledgement) data packets flowing in the return direction, which manage the data flow and ensure that it is working properly.

The bandwidth required by those ACK packets is typically equivalent to around 1/4 to 1/8th of the transfer rate you are achieving in the 'download' direction (as a rule of thumb - this is actually subject to some significant variation for a number of reasons).

As a result, if you are downloading at (say) 512 kilobits per second, you can expect to see 64-128k (i.e. up to 100%) of the 'upload' direction in a 512/128 ADSL service being consumed as well.

If you then decide to upload a file at the same time, that file upload actually slows the download because it slows down the ACK packets - and slowing those ACK packets down causes the entire data transfer to slow down.

It is the asymmetry in the ADSL line speeds which makes the effect more severe in the ADSL situation. ADSL is optimised for fast download speeds.

You should expect download speeds to be very seriously impacted by any file uploads that you may be undertaking at the same time. This is a normal consequence of the design of ADSL services.

ricey

Simple and short answer...YES