Hi,
I'm wondering if anybody has seen this 'problem', when my download speed is high (above 1 MiB/s) it goes very unstable, for instance jumping from 1.5 MiB/s to 3 Ki/s, then back to 1.2 Mi/s. All this on a daemon seen through Transmission-Qt (I haven't tried seeing if the Web client shows the same).
Observing one torrent I noticed something else, the low-speed peers behave stable, but the high-speed peers (those above about 200 KiB/s) go from downloading to nothing (not a zero, but a blank), then back... all at the same time.
It still works, just asking in case something can be improved or a bug needs to be tracked. BTW the speeds are not unusual for the devices involved, with LAN traffic easily reaching 10 times the download speeds.
[2.21] Unstable download at high speed
Re: [2.21] Unstable download at high speed
I don't think this has anything to do with protocol, so uTP is of no interest (plus its really not ready for prime time, and it will get you in trouble with private trackers which are strict with statistics and not using experimental features).
What I am interested is to hear other people's experience with high speeds, does Transmission works fine for them? do they see the same up and down really fast behavior? has anybody seen that strange all at the same time change in download?
The objective, for me, is to determine if this is worth investigating. As I said, Transmission works fine, I download torrents really fast, average speed must be around 500 to 600 KiB/s (with max at 1.8 MiB/s, min at close to zero), it just seems strange how its doing it... in other words: why low-speed peers seem to just chug along, while at the same time high-speed peers transfer in bursts?
What I am interested is to hear other people's experience with high speeds, does Transmission works fine for them? do they see the same up and down really fast behavior? has anybody seen that strange all at the same time change in download?
The objective, for me, is to determine if this is worth investigating. As I said, Transmission works fine, I download torrents really fast, average speed must be around 500 to 600 KiB/s (with max at 1.8 MiB/s, min at close to zero), it just seems strange how its doing it... in other words: why low-speed peers seem to just chug along, while at the same time high-speed peers transfer in bursts?
Re: [2.21] Unstable download at high speed
I just saw this post by Jordan: Re: Any suggestions on cache-size-mb?, I'm going to try with 8 MiB and see what happens.
Also looking at this post: Huge performance hit 2.13 >2.21 gives me the idea of watching the CPU, could that be a factor? I don't think so, but better check, I could be wrong.
Also looking at this post: Huge performance hit 2.13 >2.21 gives me the idea of watching the CPU, could that be a factor? I don't think so, but better check, I could be wrong.
Re: [2.21] Unstable download at high speed
After the first test with cache-size-mb modified, the result is yes, it does fix the wild changes and the download is stable.
Re: [2.21] Unstable download at high speed
Testing with 2 torrents, I still see some wild bandwidth changes, not as much as before but only one of the torrents was downloading above 1 MiB/s. Also maximum speed increased, I don't know if that is related to the cache size.
In the middle of the test, since there was some fluctuation, I doubled the cache-size-mb to 16, nothing changed much.
In the middle of the test, since there was some fluctuation, I doubled the cache-size-mb to 16, nothing changed much.
Re: [2.21] Unstable download at high speed
After more testing it seems to be a display bug. The bandwidth displayed does not correspond with the real bandwidth as shown for instance with vnstat.
This could be related to this bug Transfer speed shown as 0, but I only see this on individual torrents, mostly with peers with high-speed, and temporarily (1 or 2 seconds).
The cache-size-mb did appear to make operation more stable, but the same problem re-appeared at higher download speeds... I think using a bigger cache did enable reaching those higher speeds.
This could be related to this bug Transfer speed shown as 0, but I only see this on individual torrents, mostly with peers with high-speed, and temporarily (1 or 2 seconds).
The cache-size-mb did appear to make operation more stable, but the same problem re-appeared at higher download speeds... I think using a bigger cache did enable reaching those higher speeds.