Piggy-Back Effect

[spyder]

Good morning.

Can anyone explain the following, which often occurs with whatever settings (and combinations thereof) of things like slots-per-torrent, connections, etc., and firewall and antimalware on or off...

Example:

This morning I had torrent A downloading at an average of about 110 kBs.

I started another torrent ( for the same file, but from a different tracker.

Both torrents had similar seed and peer availabilities.

As the download speed of torrent B increased, so did that of torrent A, until both were coming in at around 230 kBs, each.

If I stopped either of the torrents, the speed of the remaining one fell again to around 100 - 110 kBs.

So downloading two torrents of a file often gives me a completed file in approx. half the time that a single download would.

uTorrent 1.7.7

WinXP HE SP2

ZA 6.1.744 'Free'

'Usual' uT settings (varied according to whim and for experiment):

- Global max upload (kB/s) 30

- No. of up slots per torrent 6

- Global max connections 90

- Max peers per 40

- Alternate up rate 40

Nominal Internet speeds 512kbs/1Mbs

Regards,

s.

[rafi]

seems like an error in your "nominal" speeds (=max). 1Mbps (or 512kbps) < 460kBps ... anyways, it's not very likely to be possible unless there is a bug in the speed measurements.

[Switeck]

What's your internet connection's UPLOAD max?

[spyder]

Hi.

Oops... Typo!

"512kbs/1Mbs" should have been "512kbs/10Mbs"

The internet connection's UPLOAD max is, as said,

- nominally (i.e., isp quoted): 512 kb/s;

- actual: tests between 340 kb/s and 520 kb/s, averaging 468 kbs.

s.

[Switeck]

Try a higher upload speed max, especially the alternate upload speed max while not download.

My guess is if you're uploading at 40 KiloBYTES/second then you're probably able to get at lesat slightly faster download speeds than you do now.

[spyder]

Hi.

Varying the upload speed settings (Global max. and alternative max.) has no effect on the phenomenon I described - as far as I have been able to observe.

I'm not grumbling about this: I'm quite happy with the general performance of my installation (e.g., I downloaded a file this morning at a steady 1.1 MBs, with a healthy accompanying upload rate).

It just intrigues me.

I don't think it is a uTorrent-specific effect and I know of an Azureus user who has also observed it. I think it's something to do with bittorrent in general, and was curious to know what the cause might be.

Thanks for your interest.

Regards,

s.