High Disk Usage #8606

New issue

Closed

opened 2026-02-21 19:42:42 -05:00 by deekerman · 5 comments

deekerman commented

2026-02-21 19:42:42 -05:00

Owner

Originally created by @GKid94 on GitHub (Apr 30, 2019).

I have an issue where qBittorrent uses a lot of my hard drive when I’m downloading torrents

Originally created by @GKid94 on GitHub (Apr 30, 2019). I have an issue where qBittorrent uses a lot of my hard drive when I’m downloading torrents ![4135342](https://user-images.githubusercontent.com/18757054/56950436-c5f33580-6b35-11e9-8e42-ed9618966193.jpg)

deekerman

2026-02-21 19:42:42 -05:00

closed this issue
added the
Not an issue
label

deekerman commented

2026-02-21 19:42:47 -05:00

Author

Owner

@Seeker2 commented on GitHub (Apr 30, 2019):

51.2 Mbps is about 6 MB/sec raw. Disk activity is less than double that.
Write amplification alone can explain much of that.
If you're trying to download+upload from 100 seeds+peers at once, which means the HDD is trying to access possibly 100 different places on the drive at roughly the same time..."eventually" you reach a point where the disk platters themselves cannot spin fast enough to keep up! (And probably sounds really noisy trying to!)

@Seeker2 commented on GitHub (Apr 30, 2019): 51.2 Mbps is about 6 MB/sec raw. Disk activity is less than double that. Write amplification alone can explain much of that. If you're trying to download+upload from 100 seeds+peers at once, which means the HDD is trying to access possibly 100 different places on the drive at roughly the same time..."eventually" you reach a point where the disk platters themselves cannot spin fast enough to keep up! (And probably sounds really noisy trying to!)

deekerman commented

2026-02-21 19:42:49 -05:00

Author

Owner

@Balls0fSteel commented on GitHub (May 1, 2019):

Yea this is not a bug. HDDs are horrible with random writes/reads, and torrent is a LOT of tiny pieces basically. So if you have several torrents.. or just even one thats downloading pieces here and there..things can slow down.

You can:

Increase ram cache IF you have more ram. (DO NOT go overboard, because once it fills up, your system will crawl to a halt. 512/768 is a good value I think.)
Get a second HDD and do RAID0, RAID10 (4 drives), or just get an SSD. put the system on the SSD and then qBittorrent and the rest can fight over your HDD. This is the cheapest, best solution I believe.

@Balls0fSteel commented on GitHub (May 1, 2019): Yea this is not a bug. HDDs are horrible with random writes/reads, and torrent is a LOT of tiny pieces basically. So if you have several torrents.. or just even one thats downloading pieces here and there..things can slow down. You can: - Increase ram cache IF you have more ram. (DO NOT go overboard, because once it fills up, your system will crawl to a halt. 512/768 is a good value I think.) - Get a second HDD and do RAID0, RAID10 (4 drives), or just get an SSD. put the system on the SSD and then qBittorrent and the rest can fight over your HDD. This is the cheapest, best solution I believe.

deekerman commented

2026-02-21 19:42:49 -05:00

Author

Owner

@GKid94 commented on GitHub (May 1, 2019):

I only have one active torrent and sometimes it doesn't use a lot of hard drive and sometimes it does

@GKid94 commented on GitHub (May 1, 2019): I only have one active torrent and sometimes it doesn't use a lot of hard drive and sometimes it does

deekerman commented

2026-02-21 19:42:49 -05:00

Author

Owner

@Balls0fSteel commented on GitHub (May 1, 2019):

@GKid94 Pre-allocation might also help. Takes a bit of time to start then, especially with big torrents, but much less HDD load after.

@Balls0fSteel commented on GitHub (May 1, 2019): @GKid94 Pre-allocation might also help. Takes a bit of time to start then, especially with big torrents, but much less HDD load after.

deekerman commented

2026-02-21 19:42:49 -05:00

Author

Owner

@Seeker2 commented on GitHub (May 1, 2019):

Pre-allocation should be able to use no zero-fill and take much less time on HDDs than before qBitTorrent v4.1.0.
It may require running qBitTorrent in admin mode to have enough permissions to do that.

Limiting torrents to fewer total connections (like 10-50 instead of 50+, 10 while only seeding) might also help decrease the load on HDDs while downloading.

Also decreasing the number of upload slots globally can help, because the HDD can grab slightly bigger chunks in 1 sequential read. BitTorrent works best if each upload slot can upload at least 10 KB/sec to maybe 100 KB/sec for public torrents ...or 50 KB/sec to 1 MB/sec for private tracker torrents. (competition is typically fiercer there for uploading!)
So if there's 1000 KB/sec total usable upload speed, that means no more than 100 total/global upload slots to split between ALL active torrents to achieve an average speed of 10 KB/sec per upload slot.
Download speeds for torrents should improve slightly if upload slots per torrent is at least 2 but less than max connections per torrent. Spreading upload too thin can mean peers snub your peer instead of uploading back to you!

@Seeker2 commented on GitHub (May 1, 2019): Pre-allocation should be able to use no zero-fill and take much less time on HDDs than before qBitTorrent v4.1.0. It may require running qBitTorrent in admin mode to have enough permissions to do that. Limiting torrents to fewer total connections (like 10-50 instead of 50+, 10 while only seeding) might also help decrease the load on HDDs while downloading. Also decreasing the number of upload slots globally can help, because the HDD can grab slightly bigger chunks in 1 sequential read. BitTorrent works best if each upload slot can upload at least 10 KB/sec to maybe 100 KB/sec for public torrents ...or 50 KB/sec to 1 MB/sec for private tracker torrents. (competition is typically fiercer there for uploading!) So if there's 1000 KB/sec total usable upload speed, that means no more than 100 total/global upload slots to split between ALL active torrents to achieve an average speed of 10 KB/sec per upload slot. Download speeds for torrents should improve slightly if upload slots per torrent is at least 2 but less than max connections per torrent. Spreading upload too thin can mean peers snub your peer instead of uploading back to you!