Why Do My Downloads Run At Half Speed and 'Pulse' ?

[abrogard]

My downloads seem to be limited to half my available speed - which isn't much anyway. I'm on a 512/128 adsl connection. My max download being about 50kB/s, therefore.

But I never seem to get more than 30kB/s and am much more commonly limited - and the peaks seem to be cut off, it seems to be a real limitation - to about 23kB/s.

I'd like to know why this is. I can download http, such as downloading ubuntu from their site directly through the browser, and I'll get nearly 50kB/s no problem, for at least an hour, I've seen that.

Another serious problem is that my downloading has periodic 'troughs' down to almost nothing, regular as clockwork, four times an hour. Why on earth would this be?

I've done all this other testing with prtg, downloading ftp and http and it seems to be confined to utorrent downloads. It strikes me as very strange this period four-times-every-hour behaviour and so does the speed limit.

Here's a graph from utorrent showing its most recent behaviour:

You can see the speed never gets over 24kB and the grid there is a one-hour grid so you can see clearly the pattern of four 'troughs' every hour.

Does anyone have any ideas? Up to and including directions to a 'better' program than utorrent if there is one out there?

regards,

ab

[torrero]

Do you use the xx/128k settings in the speed guide? And do you have the green network icon?

[jewelisheaven]

If you want to use a program which supports the bittorrent protocol, you can't get better than uT. I say this from both a resource usage standpoint and from an ease of use standpoint.

As for your experienced behaviour I can guess during those trough times you cannot access the internet because it is your ISP throttling your connection due to bandwidth usage. If this is not the case, it may just so happen that at those points the peers to which you are connected are reset and as such you need to wait for them to reconnect to the swarm.

Watching the Flags column under the Peers tab will also show you certain behaviours peers happen to have. http://utorrent.com/faq.php#What_do_all_those_flags_in_the_Flags_column_mean.3F

[Switeck]

Choking logic may allow retests of status once every 15 minutes...just a guess.

You may have multiple torrents going at once, only 4 KB/sec total upload speed, and get nearly instantly choked by nearly every peer on those torrents. Even the seeds see you as a "slow peer" and tend to ignore you except for their occasional optimistic upload slot.

Beyond that, your ISP may be crippling your BitTorrent traffic to a fraction of the rated speed of your line. And these bursts are just an indirect sign of the ISP's methods.

[abrogard]

Thanks for the input. I hope you're all still watching the thread... you sure get some postings in any one day, don't you?

I use the xx/128k things but I must admit they puzzle me. I'm expecting something that mimics my upload/download figures from my ISP. 512/128 is for me. Doesn't seem to fit the utorrent thing with it's 'xx'. anyway, I play with it and try to improve things. Doesn't help.

Thanks for the reassurance about utorrent being the best.

My ISP assures me they're doing nothing.

I don't come near using my available bandwidth, whichever way you interpret that much distorted (I think) expression: i.e. My total download per month or my available speed per second.

Here's an image of prtg's log of a download by http. You can see it is running at close to 500kb/s for extended periods, only having minor troughs.

utorrent's graph, posted earlier, shows a max speed of only half that and with PERIODIC deep troughs.

"choking logic" I assume refers to the method of choking my traffic employed by my ISP. Well, he swears there's none, so that's that. My graph indicates there's certainly none for http.

'multiple torrents at once.." Sometimes I have two. Never more. This behaviour is consistent whatever. Usually I have only one. At the time of the posted graph there was only one.

I would really like to know what it means: "....get nearly instantly choked by nearly every peer on those torrents...."

Looks like a possible answer there. But I'm ignorant of the whole thing. My peers can choke traffic to me, can they? And they would do that if they perceived me to be a "... slow peer..." ?

Can someone explain this to me a little more fully? So I'll be in a position to find out if this is what happens and will be able to modify things to overcome it?

regards,

ab

[jewelisheaven]

So HTTP downloads @ 55 KiBps and uT only hits 32 KiBps... hmm. Just because the ISP doesn't interrupt connections doesn't mean they AREN'T shaping your torrent traffic, or the ISP(s) your ISP peers to don't. What you need to watch is the Flags on the Peers tab when your downloads are about to dip down. It's not a constant "pulse" as shown in your graph above there was a whole ~ 1 hour when you were at "full speed" so it means it can be done. What Switeck was saying, if you are cutting your upload into too many slots (upload speed / (torrents * slots)) you will not be given priorities in the swarm... 128Kbit is ~ 16KiBps max you may see 12, so definitely less upload slots is better, have you tried just 1 slot?

[abrogard]

My ISP (aanet.com.au) swears they do nothing beyond limit me to my 'plan' - 512kbs up/128kbs down.

It IS a constant pulse on utorrent. The one hour of full speed was with an http download (downloading ubuntu from their site). There is no one hour of full speed on the utorrent graph. There is no one minute of full speed on the utorrent graph.

That's what I posted the graph for - to show that full speed is attainable and is attained and is maintained. In fact it is no problem at all. I can and do achieve that speed anytime with http downloads. Or ftp. If my ISP were interested in choking my downloads why/how would he single out the utorrent protocol (whatever that is) ? But, of course, he denies any such interest.

You will notice when an ftp download was initiated it only hit half speed and it dropped the http download to half speed. They ran together for a few minutes sharing the available bandwidth 50% each. When a 'trough' hit the ftp the http used the now available bandwidth and its speed rose for a while.

That's the sort of interaction one would expect.

There is a little spike on the utorrent download at about 14:37 that isn't matched by a trough on the http download. I don't know why this is.

I'll check my upload slots and limit them to one (when I find how and where it's done).

Thanks for the input and interest, guys.

I'm continuing to download and I'm still getting the same behaviour and I'm running PRTG all the time so I'll have graphs of that behaviour covering days.

regards,

ab

[jewelisheaven]

Actually, in your uT speed tab picture, there are several hour sections which show your sustained upload without dips (5 min scale means each horizontal gridline is 1 hour apart). Peaking @ 74 or near it is STILL over your 440Kbps (74*8=592)... I'm not seeing a problem aside from the possibility you get RST packets from those peers giving you such nice upload speed :/ Could you restart the problem/question you have another way maybe??

The settings from the Speed Guide are changed in Ctrl-P -> BitTorrent and Connections (changed to singular Bandwidth Preference pane in 1.8).

[abrogard]

You've lost me. We don't seem to be on the same page. We're talking about the graphs I've posted right here on this thread?

I've posted two.

(1) Is a utorrent graph. It was the first one posted. It demonstrates, illustrates, the problem with utorrent: Max speed less than 24kB/s and regular - always four times per hour - 'troughs' when the speed drops to less than 6 kB/s.

This is my 'uT speed tab picture' that you mention and is shows NO hour sections of sustained speed without dips. All it shows is periodic ups and down at a frequency of 4 times an hour between <24kB/s and about 6kB/s.

THIS is the problem.

The VERTICAL lines are spaced one hour apart. The horizontal lines mark the speeds.

(2) Is a PRTG graph, the second post. It demonstrates my equipment (and my ISP etc) allows for and obtains download speeds of greater than 24kB/s - in fact twice that speed.

It shows - the single line - an http download running without deep troughs at nearly 50kB/s.

It shows this speed (which represents my total bandwidth) dropping to halfway when an FTP download ( a speed test ) is initiated. It shows the speed of the http download rising immediately to 50kB/s when the FTP stops.

I then switch off this download and initiate utorrent again. It shows utorrent, as usual, rising to only 24kB/s.

This graph demonstrates that there IS a problem. i.e. my computer is not downloading as it should.

If my computer were only capable of what the utorrent graph shows then there'd really be no problem. I just would need another machine.

But it is not so.

That's the whole point of my posting the other (PRTG) graph.

NOW I can reveal that I've found the answer to half the problem. Half. To the max speed thing. But I still haven't found the answer to the periodic 'troughs', 'dips'.

I switched off Peer Guardian. That seemed to fix it. I swear I switched it off before - I have 'Scotty', 'Peer Guardian' and 'Trojan Hunter' normally running, each with an icon in the tray.

I'd swear I repeatedly, during the course of this testing, switched the three of them off. It's easy enough. Right click on their icons and switch them off. I'd swear I did it. But I must be wrong. Because now I can switch Peer Guardian back on and see the speed drop. Switch it back off and see it rise.

BUT - still got spikes.

Here's a couple of graphs:

This one is a one hour graph from PRTG and it shows a lovely 25 minutes of sustained download by utorrent at about 50kB/s. It also shows two troughs occurring after this tremendous display with the download rate rising back to 50kB/s after each.

And this one is a 24 hour graph from PRTG spanning the time of the one hour graph and it shows what's been happening for the past 24 hours, especially since 0830 when I disabled Peer Guardian. An immediate doubling of peak download speed - since 0830 700MB downloaded - but no reduction in the frequency of the 'troughs'.

I find it interesting that the bottom of the troughs now seems to be where the peak speed used to be. i.e. they are dropping to around 24kB/s . I'm losing half my speed at each trough.

So I'm smiling but if I can get rid of those nasty troughs then I'll be laughing....

any clues, anyone ?

regards,

ab

[Switeck]

Download Limited effects in uTorrent probably ironically are making both your upload and download speed even worse than it should be.

BitTorrent protocol has peers and seeds uploading as fast as allowed to those that download quickly. Right now, yours can't (for whatever the reason), so peers and seeds "choke" your connection and often get where they only upload to you in bursts/short intervals...and these may be 15 minutes apart due to optimistic unchoke.

Limiting upload speed to 4 KiloBYTES/sec in uTorrent automatically hard-limits download speed to 24 KiloBYTES/sec. Beyond that, if the download speed max is briefly reached then I'd expect to see at least a small, temporary upload speed drop.

Try these settings in uTorrent:

1 active torrent, so make sure it's a good one for these tests!

6 KiloBYTES/sec upload speed

2 upload slots

30 total connections per torrent/global

4 half open connections

[jewelisheaven]

The circled areas are > 15 minutes. That's all I was talking about Yea I can see NOW the average is 24... previously I saw it as 74 which is why I responded like I did :/ The disconnects are your ISP telling your modem you're using too much of SOMETHING... either bandwidth (MiB) upload / download or concurrent connections, or cycling connections. You can first try disabling the extra settings as described in post #2 of the How-To. Alternatively you can first try limiting your settings connection wise, peer wise, halfopen wise, connect speed wise... if that helps :/ Sorry again about my misunderstanding of your graph

As for PeerGuardian... bleh, useless and false sense of "security", bleh again.

Whatever it was doing it was keeping you from using that speed... another reason to not use it

Blocking by region or whatever won't block the "bad guys" from finding you.

http://neuron2neuron.blogspot.com/2006/05/blocklist-balderdash.html

http://www.slyck.com/story1593_MediaDefender_Leak_Offers_BlueTack_Users_a_Reality_Check

[abrogard]

Limiting upload to 4kBs automatically limits download!!! Well, there you go....

How does that work? I should have known that? The relationship works with all speeds?

I'll follow your recipe and let you know what happens.

- Well, I'll try to follow it. I couldn't find where I set the 'half open' - and what about total global connections as distinct from total per torrent? I've got it set at 80.

I'll look for something to download this evening and post the results tomorrow. How I can safely choose a good one I don't know, just hope for the best.

ab

[jewelisheaven]

!!! I didn't even touch on that, yea. Sorry EEP You never mentioned "what does this 'download limited' mean?" so I was unawares thats where your hard limit came from, lol. Yea those limits have been in since... uhm 1.3??? You'd have to ask Firon. When you set your upload.. aww hell I explained it better than I can at this hour. I hope you don't mind I didn't retype that all. Any other questions in the meantime>?

[Switeck]

Yes, at very low upload speeds...download speeds get crippled too.

At the other end of the spectrum, if your upload speed is set too high (beyond what your connection can do) then your download speed also takes a severe nosedive.

Still, there's a big range of upload speeds you can use that should get decent download speeds.

Hopefully my suggestion helps.