Speeds peaking and plummeting while torrenting

[airvpn18259 2]

Ok so I'm on a 100Mbit broadband connection and I'm able to max out my connection (with and without VPN) on speedtest sites. However while torrenting, I notice that the the speed will peak for 2-3 seconds, then plummet for 2-3 seconds then again peak for 2-3 seconds then again plummet for 2-3 seconds.

 

Here's a graph showing exactly what I mean:

 

 

 

So the peak download speed (in green) is around 11MB/sec (~88Mbit) and trough is around 2MB/sec (16Mbit).

 

Any ideas?

[LZ1 672]

Hello!
 

Have you done portforwarding? Tried changing TAP drivers? Tried the Eddie client? Or tried the Experimental?

 

You provide precious little information haha.

[bifter 0]

I'm getting the same issue...I have just installed Eddie 2.11.8 from the latest stable. I tried going back to stable but got lots of null errors (I guess the some config settings have been overwritten by Eddie?).

 

macOS 10.12.1

Eddie 2.11.8

I am port forwarding.

 

UPDATE:

I have reverted to 2.10.3 and am still getting the same issue.

​

UPDATE 2

​Ok, after reading other comments here I identified the cause to saving a torrent to a USB 2 stick

[go558a83nk 362]

Ok so I'm on a 100Mbit broadband connection and I'm able to max out my connection (with and without VPN) on speedtest sites. However while torrenting, I notice that the the speed will peak for 2-3 seconds, then plummet for 2-3 seconds then again peak for 2-3 seconds then again plummet for 2-3 seconds.

 

Here's a graph showing exactly what I mean:

 

 

 

So the peak download speed (in green) is around 11MB/sec (~88Mbit) and trough is around 2MB/sec (16Mbit).

 

Any ideas?

 

could it be a hard drive cache flushing problem or the like?

[rainmakerraw 94]

What torrent client are you using? I see you're on Windows, so I would highly recommend qBittorrent because it's fast, light, ad-free and secure (you can bind it to the TAP adapter). Just to make sure, have you disabled uTP and rate limiting in your torrent client? I had all kinds of hair-pulling annoying speed issues until I realised that one. Also make sure to set the snd and rcv buffers to 512K to rule that out, and connect to your router via ethernet to rule out wifi drops (this type of graph is quite common on poor wifi).

[airvpn18259 2]

What torrent client are you using? I see you're on Windows, so I would highly recommend qBittorrent because it's fast, light, ad-free and secure (you can bind it to the TAP adapter). Just to make sure, have you disabled uTP and rate limiting in your torrent client? I had all kinds of hair-pulling annoying speed issues until I realised that one. Also make sure to set the snd and rcv buffers to 512K to rule that out, and connect to your router via ethernet to rule out wifi drops (this type of graph is quite common on poor wifi).

 

I'm on qBittorrent 3.3.7. No rate enabled anywhere in client or router or OS.

 

I actually don't think it's the VPN that's causing the fluctuation. I have a 5 year old PC so either the HDD is slowing down or the RAM or CPU not performing up to the mark (?) I'm not quite sure.

 

Is there a way to find out what exactly the problem is? Is it a hard drive cache flushing problem?

 

Thanks 

[zhang888 1066]

Shortest and most productive test would be to download a well seeded Linux torrent without VPN and compare.

[airvpn18259 2]

I performed test with and without airvpn:

 

This is WITH airvpn enabled: http://i.imgur.com/YiZlieU.jpg

 

This is WITHOUT airvpn: http://i.imgur.com/gWjmpGa.jpg

 

So it's definitely not the VPN, but I'm not sure what it is. Why do speeds hit max 14MB/sec (The 110Mbps I get max from my ISP) then drop to 10MB/sec (80Mbps) every 3 seconds?

 

Would it be a CPU issue or a drive issue or a RAM issue?

[zhang888 1066]

One of the possible reasons is that your network I/O exceeds the disk I/O, so you have bufferring until the previous write operations are completed.

[airvpn18259 2]

Ok in that case what's the fix? Sorry a newbie here. Do I need a better CPU? Or HDD?

[zhang888 1066]

SSD.

[Staff 9972]

Would it be a CPU issue or a drive issue or a RAM issue?

 

Hello,

 

1) enlarge considerably torrent client RAM buffer, so that it writes to the HDD less frequently

2) if you have an asymmetric line make sure that the upload bw of the torrent client does not choke the line (set stricter limits from the torrent client options)

3) if you have some file system that has no effective algorithm to avoid fragmentation, defragment the HDD

4) consider zhang888 suggestion. If you have USB 3, even a good USB key might be enough. Make sure to take one that can support at least 28 MB/s in writing and set the external storage in the torrent client options.

 

Kind regards

[rainmakerraw 94]

As I have said elsewhere, I have had a similar issue on my 200/20 cable line, with MacOS, Linux and Windows, on SSD and HDD. I have had a play with qBittorrent 3.3.7 and found that I have fixed my issue, so hopefully this helps you also. It's worth a try. 

 

Maximum number of connections per torrent: 100 (50 works too but isn't always as fast)

Global rate limits - upload - 75% of your upload speed

Make sure every other box on that page (including 'Enable uTP protocol') are not checked

 

 

Go to the Advanced section and scroll down to libtorrent settings.

 

Disk write cache size - 30 MiB

Enable OS cache - Make sure you uncheck this

Maximum number of half open connections - 0 (zero)

 

 

Now restart qBittorrent and try an Ubuntu 16.10 torrent download again. I tried settings ranging from large cache sizes (4000 MiB and down) and found that on a standard hdd a setting just above my line speed (30 MiB in my case) worked the best. If 30 doesn't work for you, try 20. I found that the OS cache option just made the torrent spool up slower and it 'crashed' the speed a few times while the disk caught up. This doesn't happen (for me) with OS cache disabled. As zhang888 says an SSD is much more reliable. When I switched my download path back to my SSD speeds were more stable and it didn't matter so much when the buffer wrote to disk, but for a platter HDD it was just too much with such a high network speed. 

 

Worth a try mate and if it doesn't work for you it's easy to switch them back. I've gone from having a speed graph that was way worse than yours (up and down every couple of seconds, 20 MiB/sec to 1 MiB/sec) before eventually giving up and staying around 1-2 MiB/sec permanently. Now I can download at 20 MiB/sec without breaking a sweat.

[rainmakerraw 94]

PS: I have just noticed at the top of the Networx graph photo you posted that it says 'All Wireless Connections'. Speed fluctuations like that can also be a wifi issue, so before anything I would try to use ethernet to rule out the wifi. If it works OK on ethernet you can save a lot of hassle tweaking and work on that (change channel, change channel widths, change PHY). If it still happens then you know it's probably a machine/disk/cache issue.

[airvpn18259 2]

Guys I just wanted to update this thread. I found out the issue. It wasn't my HDD, SSD, CPU or RAM issue. It was my external USB Wireless adapter that kept dropping connections every few seconds. I got a new wireless adapter and it's been working flawlessly.