Faster downloads- tweaking and sequential transfers

[xavier242]

Here's a tweak guide DH and I created for uTorrent 2.2.1:
https://www.reddit.com/r/utorrent/co...aks_and_notes/

Can someone explain why sequential transfer can be detrimental for an initial seeding swarm? I don't see the issue as long as some folks continue to seed.

[zoso69]

Many thanks Xavier. Do you happen to have one for BiglyBT?

[xavier242]

Originally Posted by zoso69

Many thanks Xavier. Do you happen to have one for BiglyBT?

According to this, it can do sequential (required to stream a torrent):
https://www.reddit.com/r/BiglyBT/com..._for_advanced/

Look in the program options or settings for enabling streaming (it might be called that instead of sequential downloading). It may be like qBittorrent where you can only set it in the download dialog (not globally for all torrents).

I did some more reading on sequential downloading and like I guessed, as long as some seeders remain, a new swarm remains healthy even if everyone downloads sequentially. I've not seen any torrent where everyone hits 'n runs (not that it doesn't ever happen).

Knowing this, I wonder why the default in most (or all) programs is to download pieces in random order? Seems quite strange given that the setting was (possibly) decided when spinning mechanical drives were king (SSDs don't care either way).

DH tells me his seedbox upload speeds are much faster since I posted the suggestion.

If you didn't read the uTorrent 2.2.1 tweak guide on Reddit, here's the TLDR:

Use a dedicated local (not network) drive for your uTorrent download folder. If you use a SSD, it may be ok to share with the operating system. But if uTorrent's GUI ever freezes, you must use a dedicated local spinning or SSD drive (USB 3.x external is fine). Don't use qBittorrent or uTorrent 3.x for downloading (both have major bugs).

from the uTorrent 2.2.1 Reddit post:

Sequential Transfers:
By default, bittorrent transfers are random pieces of the file(s). This is the worst possible load for spinning (older mechanical) drives. My spinning RAID6 array does 1600MBytes/sec for sequential transfers, but plummets to 2.5MBytes/sec for random transfers. Non-array spinning drives do better, maybe getting 10MBytes/sec. SSDs do about the the same speed for sequential or random.

When downloading from long-term seeder(s) that are using spinning drives, you will greatly reduce the load on the server drives and see higher speeds if you set uTorrent to transfer sequentially. This is a global setting affecting all transfers:

Have no torrents selected. Press and hold Shift and F2 simultaneously. Keep holding them down and click the Settings button.

These now appear in the Advanced settings list. Change to:
bt.sequential_download true
bt_sequential_files true

[Deadmarsh]

I have had the client (uTorrent 2.2.1) become unresponsive twice after I made the tweaks last week. Not sure what is causing it. I'm not using temp folders. I noticed the client stops writing resume.dat and settings.dat files when this happens. This has not occurred before.

[Datahound]

Originally Posted by Deadmarsh

I have had the client (uTorrent 2.2.1) become unresponsive twice after I made the tweaks last week. Not sure what is causing it. I'm not using temp folders. I noticed the client stops writing resume.dat and settings.dat files when this happens. This has not occurred before.

The SSD settings for sparse file, part file, and pre-allocation in that Reddit post do place more load on the drive. It you have plenty of space, do not use those settings (use the spinning disk settings). It's intended to conserve space on a small 400GB or 480GB SSD when uTorrent is configured with a download temp folder.

Are you using a local (not network) dedicated drive for the downloads folder? If not, this is a possible cause. uTorrent 2.2.1 doesn't share disk I/O well. If you have a dedicated consumer SSD or mechanical spinning drive, get an enterprise 400GB MLC SSD for $25-$30 from eBay (Intel DC S3700 or newer). Plug it into a motherboard SATA port. Configure a download temp folder.

I can attest that the drive handles 950 simultaneously transferring downloads (combined total around 35MBytes/sec) over IVPN and uTorrent remains responsive. Note you need a lot of CPU for that many- I saw a max of 85% usage on a Core2Duo (stock HP DC7900 with Win 7 x64). CPU starvation could also cause stability issues in theory (not really an issue with any modern processor).

Anything that bottlenecks disk I/O could cause freezing. SATA chipset, driver used for it, noise (bad cables/connectors, power supply), faulty AHCI implementation- there were a lot, Intel shipped millions of bad chipsets/drivers with AHCI as the default.. the DC7900 was one. Works fine in legacy IDE mode (they released drivers like 5 years later that fixed the AHCI issues but I didn't try them).

For pre-2014 motherboard SATA ports, I avoid AHCI and use legacy IDE mode. The speed difference with SSDs is not significant. Even with spinning drives, it's not worth the risk. However, any motherboard made in the last 9 years is probably ok, but like I said, you won't notice any speed difference with a SSD.

Most of my boxes use 3Ware or LSI RAID for the bulk storage which I'm guessing is using AHCI since NCQ is supported.

Another solution is to slow it down. Set global rate limits like under 4MBytes/sec. Disable UTP. Lower the number of connections per torrent. Rate limit on a per torrent basis. This is a pain, but it's how I'm able to use uTorrent on a virtual machine writing to a network drive (I have valid reasons for such a config; plus it gets very little use). Limit the number of active torrents.

[Deadmarsh]

Originally Posted by Datahound

The SSD settings for sparse file, part file, and pre-allocation in that Reddit post do place more load on the drive. It you have plenty of space, do not use those settings (use the spinning disk settings). It's intended to conserve space on a small 400GB or 480GB SSD when uTorrent is configured with a download temp folder.

Are you using a local (not network) dedicated drive for the downloads folder? If not, this is a possible cause. uTorrent 2.2.1 doesn't share disk I/O well. If you have a dedicated consumer SSD or mechanical spinning drive, get an enterprise 400GB MLC SSD for $25-$30 from eBay (Intel DC S3700 or newer). Plug it into a motherboard SATA port. Configure a download temp folder.

I can attest that the drive handles 950 simultaneously transferring downloads (combined total around 35MBytes/sec) over IVPN and uTorrent remains responsive. Note you need a lot of CPU for that many- I saw a max of 85% usage on a Core2Duo (stock HP DC7900 with Win 7 x64). CPU starvation could also cause stability issues in theory (not really an issue with any modern processor).

Anything that bottlenecks disk I/O could cause freezing. SATA chipset, driver used for it, noise (bad cables/connectors, power supply), faulty AHCI implementation- there were a lot, Intel shipped millions of bad chipsets/drivers with AHCI as the default.. the DC7900 was one. Works fine in legacy IDE mode (they released drivers like 5 years later that fixed the AHCI issues but I didn't try them).

For pre-2014 motherboard SATA ports, I avoid AHCI and use legacy IDE mode. The speed difference with SSDs is not significant. Even with spinning drives, it's not worth the risk. However, any motherboard made in the last 9 years is probably ok, but like I said, you won't notice any speed difference with a SSD.

Most of my boxes use 3Ware or LSI RAID for the bulk storage which I'm guessing is using AHCI since NCQ is supported.

Another solution is to slow it down. Set global rate limits like under 4MBytes/sec. Disable UTP. Lower the number of connections per torrent. Rate limit on a per torrent basis. This is a pain, but it's how I'm able to use uTorrent on a virtual machine writing to a network drive (I have valid reasons for such a config; plus it gets very little use). Limit the number of active torrents.

The first time occurred when I wasn't even downloading anything. Not using the SSD settings. No local network. Downloading to a spinning drive. Client itself is on an SSD. If this happens again I'll just undo these changes as I had zero issues before.

[Datahound]

Originally Posted by Deadmarsh

The first time occurred when I wasn't even downloading anything. Not using the SSD settings. No local network. Downloading to a spinning drive. Client itself is on an SSD. If this happens again I'll just undo these changes as I had zero issues before.

That's a good idea. It's possible the uTorrent tweaks are not compatible with all hardware/OS combinations.
DH

[Deadmarsh]

Yeah, my issues aside, the downloads are indeed much faster with these settings.

[Deadmarsh]

Since last message got a memory error two times (Windows supposedly out of memory while there was approx 16GB available), IO error once (related to the first memory error) and now frozen UI again (no downloads active). Reverted all settings from a backup to see if something odd still happens. I had reverted some settings already before, but can't be bethered anymore to keep trying to guess what combination of changes doesn't work on my system.

[distro68]

I am ignorant of most workings but can only say that for some reason I am now prevented from downloading anything any more . I have downloaded easily for about 15 years under the previous system and have got some great music .

[xavier242]

Originally Posted by Deadmarsh

Since last message got a memory error two times (Windows supposedly out of memory while there was approx 16GB available), IO error once (related to the first memory error) and now frozen UI again (no downloads active).

About the frozen UI: is this with a dedicated download drive? If so, you have other issues: bad drivers, hardware, conflicts with other software/drivers/hardware. As you can see, this is difficult to troubleshoot and a waste of time (try a different PC).

Verify these:
Maximum number of connected peers per torrent: 5 or less (minimum of 2)
Number of upload slots per torrent: 2 or 3
If any higher, can cause issues. Set upload and download global limits to 500 (this is quite slow, but if the GUI still freezes... um time to use a different PC).

The memory error is normal with a crapton of use. It's running out of heap memory (which is the same no matter how much physical RAM you have). It's a bug. No fix I'm aware of. Just stop all the torrents (if possible). Close uTorrent. Open task manager and make sure it ended. If is doesn't end after 30min, kill it. Reopen, and on any torrents with errors, recheck and then Start. You can proactively do this and avoid the memory error. I restart uTorrent like once a month with normal use.

You should make a clean install on another PC. Get all your settings proper and make a backup of your utorrent profile folder. Copy the utorrent.exe from the Program Files folder to your profile backup (aka template). That is now your clean template you can copy anywhere and run in portable mode by creating a special shortcut containing like:
D:\UT05-prog\uTorrent.exe /RECOVER

In this case, uTorrent is running on my 5th instance (UT05-prog folder) from the D: drive. /RECOVER tells it to run in portable mode using the utorrent.exe you copied with the settings contained in that folder.

My portable instances are all created from one known good template. It's the best way to run it. If anything breaks on one profile, just delete all the files/folders and copy the files/folders from your template folder to the broken folder (note this will wipe out that profile's loaded torrents and settings, replacing them with what you template has; keep this in mind if using magnet links). I've not had to do this (it's not broken for me since discovering the dedicated drive and/or rate limit tweaks).

You can create multiple different portable templates with different configs. Just name the template folder appropriately to tell you what it's for. In portable mode you can have different torrents in different profiles. This is useful on Dime for seeding more than 60 torrents (not at the same time).

Portable mode doesn't work on 3.x. Not sure why.

Windows has had many hardware/drivers/software conflicts over the years. Look up "race conditions (software)" to understand how bizarre things can get. Seemingly unrelated processes can affect each other when they share an underlying resource or state (sometimes indirectly via a separate process...) Sometimes you can only avoid known conflicts. Like Dell branded Toshiba 4TB drives are not fully compatible with 3Ware 9650SE RAID controllers, but 4TB Toshiba brand drives with the same model number work great (this is a true experience I recently discovered). The Dell drives are fine when used in any other config I've tried. I could give you a hundred examples like this.

[javieracdc]

what about utorrent upload tweaks?

[Deadmarsh]

Originally Posted by xavier242

stuff

No problems since I switched back to older settings I have had for a long time. Can't be bothered to to track down what the problematic setting combo is. And uTorrent was the only thing acting up. If there would be hardware problems they would have already manifested in some other way too.

[marksg]

Utorrent 2.2.1 had a great run, but it is displaying more and more issues with W10 and 11. Personally, I reluctantly switched to qbittorrent, and it has been problem free.

[Deadmarsh]

Originally Posted by marksg

Utorrent 2.2.1 had a great run, but it is displaying more and more issues with W10 and 11. Personally, I reluctantly switched to qbittorrent, and it has been problem free.

How did you migrate to it?
I have 6500 active torrents and I would like to be able switch without having to add and map every torrent again. I have also renamed most torrents in the client (as it's possible) for sorting purposes. Doing that again is also something I'm not looking forward to.