Unstable speed when downloading multiple big torrents

[Kiicki]

Version

qBittorrent v4.1.3 and Windows 10 1803 (OS Build 17134.345)

Computer Specifications

Component	Selection
Motherboard	Asus ROG Strix B350-F Gaming
Power Supply	EVGA SuperNOVA G3 550W
CPU	AMD Ryzen 5 1600 3,2GHz Socket AM4 Box
Video Card	Asus GeForce GTX 1060 Dual OC 2xHDMI 2xDP 6GB
Memory	Corsair Vengeance LPX Black DDR4 PC25600/3200MHz CL16 2x8GB (CMK16GX4M2B3200C16)
SSD	Samsung 840 EVO 500GB
HDD	Seagate Barracuda ST4000DM004 256MB 4TB

Internet connection

260/260 mbps Wired connection

Problem

I'm currently downloading 6 torrents:

• 33.20 GB
• 55.98 GB
• 72.17 GB
• 83.16 GB
• 180.60 GB
• 188.08 GB

The speed is very unstable. It can go as high as 15-20MB/s and drop down to a few KB/s in a matter of seconds. It does this frequently too. I'm downloading my torrents to my HDD. This problem seems to occur when I download several torrents at once, where the torrents are big in size. This seems to be a common problem, and I believe that I noticed this for the first time when qBittorrent version 4 launched. I don't download several big torrents at the same time frequently, so this problem hasn't really been an issue, but I see that it's still a problem today.

What has worked?

I thought that maybe it was my HDD limiting the speed. My HDD seems to be maxed out at 100% usage when using qBittorrent. Maybe that it couldn't handle that much data at once, but I tried Deluge 1.3.15 without any problems. Deluge took maybe a minute or two to start downloading all the torrents, and it took maybe a minute or two to reach top speed, but once it got going it was stable.

Video 60fps

qBittorrent is also lagging. I think there's a lot of stress on my HDD, even though qBittorrent is installed on my SSD. I didn't experience this with Deluge.

https://vimeo.com/297478233

Screenshots

[Seeker2]

Were there only a few connected seeds+peers on these torrents?
...possibly even the same peers+seeds across many torrents instead of a random mix on each?

qBT seems to have a connectivity weakness in that it connects to fewer peers+seeds than other BT clients from what I've seen.

[Kiicki]

Were there only a few connected seeds+peers on these torrents?
...possibly even the same peers+seeds across many torrents instead of a random mix on each?

qBT seems to have a connectivity weakness in that it connects to fewer peers+seeds than other BT clients from what I've seen.

I have used the same 5-6 torrents with Deluge, and I had no problems there. Honestly, qBittorrent just seems laggy, and it seems hard on my HDD. I do have a total of 118 torrents in qBittorrent, but most of them are small, and only these 5-6 torrents were active. Even with slow speed, my disk usage was at 100% because of qBittorrent.

The program itself is pretty slow atm, even with everything paused. With everything paused, the disk usage shows 0%, but qBittorrent still runs pretty slow. Dragging it across is slow too.

I tried an old version of utorrent 2.2.1 and I had a similar issue. I loaded these 5-6 torrents,, but started with decent speed until it showed a few KB/s. It never went up again, and when I exited utorrent, it was still open in my task manager, and it took time to get rid of it. When I finally did and launched utorrrent again, it had to "check" all my torrents.

So it's possible that it's my hardware, but it's odd how Deluge stayed so stable. I don't know if the problem is caused by me downloading my torrents to my HDD instead of my primary SSD.

Edit: So I figured out why qBittorent was lagging/stuttering. It was because I had the "speed graph" opened. Doesn't explain the unstable speed though.

[FranciscoPombal]

Duplicate of #7954. See #7954 (comment)