SABnzbd Forums

Hello friends.

I've been using SabNZBD for many, many years and everything has been perfect, up until about 3months ago. For some reason, my download speed using SabNZBD is half of what it should be and I cant figure out why.

I have the service running on a rasp pi 5 8gb/docker with an nvme m.2 crucial t500 and ive been able to pull 100MB/s or so up to around 3 months ago, when for some reason, after no changes, it is now not able to get more than around 45-50MB/s. I have a 1.2gbps/900 connection. Im using ewaka news servers, 50 connections (tried lowering this), ssl enabled. I have a full speed account.

The weird thing is if I run SabNZBD on my Windows PC I'm able to pull full speeds, but my pi 5 just is having some issue that I cant figure out. Here is the pystone for the pi 5:

Linux-6.6.74+rpt-rpi-2712-aarch64-with NEON Docker
System performance (Pystone) 323688
Download folder speed 460 MB/s /downloads/incomplete
Complete folder speed 452 MB/s /downloads/complete
Internet Bandwidth 108.78 MB/s 870.24 Mbps

Test download on pi 1gb:
test_download_1000MB Downloaded in 20 seconds at an average of 51.5 MB/s

The pi is connected with a cat 7 cable to my router (2.5gb, although only 1gbps via the pi, auto negotiated, pi is able to pull full speeds from other sources on the internet). I thought maybe that my ISP was throttling usenet speeds but my windows pc is able to get full speed, so this cant be the case. I then thought it might be some config issue, but Ive really looked at everything I can and everything looks fine. Ive also tried disabling direct unpack and the article cache is set at 1G. Ive also tried a full reinstall of rasp pi OS (64bit headless) and no change.

I was just wondering if anyone suffered similar unexplained issues, or had any idea why this would be happening. Thank you!!

Thorough research. Nice!

During a download: what does 'btop' show as CPU usage?

What if you disable SSL and download again?

I hope you have not set a max bandwidth in SABnzbd?

sander wrote: ↑March 3rd, 2025, 4:47 am Thorough research. Nice!

During a download: what does 'btop' show as CPU usage?

What if you disable SSL and download again?

I hope you have not set a max bandwidth in SABnzbd?

With btop running and a 10GB test file active, the CPU was at 2.4GHz, usage was roughly 17-19% with a couple spikes to 40% or so here and there. The temperature was roughly between 45 and 48 degrees C. Running this with SSL enabled or disabled doesn't change anything sadly.

Also there is no max bandwidth set that I can see. Percentage of line speed is set to 100

littlecat wrote: ↑March 3rd, 2025, 5:06 am Also there is no max bandwidth set that I can see. Percentage of line speed is set to 100

If you can set percentage, you have set a linespeed ... not good. Check via http://127.0.0.1:8080/config/general/#b ... _max_value ... or search "Maximum line speed".

sander wrote: ↑March 3rd, 2025, 5:12 am

littlecat wrote: ↑March 3rd, 2025, 5:06 am Also there is no max bandwidth set that I can see. Percentage of line speed is set to 100

If you can set percentage, you have set a linespeed ... not good. Check via http://127.0.0.1:8080/config/general/#b ... _max_value ... or search "Maximum line speed".

https://imgur.com/a/TTHQPrS

If it's this option I've always left it blank and never had issues. Tried again now though after setting my max line speed but sadly with no change.

After the 10GB test download, in the Wrench: nothing with "limited by ..."?

What is the speed with the 100MB test download?

sander wrote: ↑March 3rd, 2025, 5:40 am After the 10GB test download, in the Wrench: nothing with "limited by ..."?

What is the speed with the 100MB test download?

test_download_100MB Downloaded in 1 sec at an average of 54.6 MB/s
test_download_1000MB Downloaded in 23 seconds at an average of 45.3 MB/s
test_download_10GB Downloaded in 3 mins 34 seconds at an average of 49.4 MB/s

System load 0.95 | 0.62 | 0.28 | V=148M R=94M
System performance (Pystone) 329080 Linux-6.6.74+rpt-rpi-2712-aarch64-with NEON Docker
Download folder speed 475.9 MB/s /downloads/incomplete
Complete folder speed 479.7 MB/s /downloads/complete
Internet Bandwidth 108.68 MB/s 869.44 Mbps

Tried all 3 of the test options with the above results. Nothing was in the "wrench" about limitations during/after the downloads. Htop during all 3 produced similar results to what I saw before. So, it's all a bit of a mystery as to what I'm messing up here.

Well, then I'm out of ideas, and your're on your own!

(long long shot: create a fresh OS on a fresh SD-card, and check SABnzbd with that)

sander wrote: ↑March 3rd, 2025, 11:19 am Well, then I'm out of ideas, and your're on your own!

(long long shot: create a fresh OS on a fresh SD-card, and check SABnzbd with that)

Out of interest, is there any benefit/need for trying a fresh SD card? I did recently reinstall the OS with a fresh image but on the SD card I already had. I only have one SD card right now anyway, but if it does make a difference trying a fresh card Ill pick one up later this week and re-try. Appreciate the help and replies anyway.

No, doesn't matter.

But the great thing of an SBC with an SD card: if you have a running setup on SD-card #1 ... you can try another setup on SD-card #2. That's how I do it: like trying out a new or other OS version.

Decided to try a VPN just to rule out things completly and to my suprise, things are working correctly while connected using a VPN.

test_download_1000MB Downloaded in 11 seconds at an average of 93.0 MB/s

So it seems something is throttling the connection to my pi specifically while trying to use usenet, as my PC is able to pull full speeds without a VPN on the same network.

Interesting.. but for now this will work as a fix for me.

littlecat wrote: ↑March 4th, 2025, 1:36 pm Decided to try a VPN just to rule out things completly and to my suprise, things are working correctly while connected using a VPN.

test_download_1000MB Downloaded in 11 seconds at an average of 93.0 MB/s

So it seems something is throttling the connection to my pi specifically while trying to use usenet, as my PC is able to pull full speeds without a VPN on the same network.

Interesting.. but for now this will work as a fix for me.

Interesting indeed!

"So it seems something is throttling the connection to my pi specifically while trying to use usenet,"

Yes. Options:
- on your Pi itself. Problem with hardware/driver ... ? But why then not with a VPN ... which works via the same hardware/driver(?)
- on your LAN.
- on your router. Packets handled in a different way ... because different destination? Or MTU-size thing?
- outside your router. So your ISP. But if your ISP does that, why only PI and not Windows (coming from same public IPv4)?

I see no likely or possible cause. Weird.

sander wrote: ↑March 4th, 2025, 2:04 pm Interesting indeed!

"So it seems something is throttling the connection to my pi specifically while trying to use usenet,"

Yes. Options:
- on your Pi itself. Problem with hardware/driver ... ? But why then not with a VPN ... which works via the same hardware/driver(?)
- on your LAN.
- on your router. Packets handled in a different way ... because different destination? Or MTU-size thing?
- outside your router. So your ISP. But if your ISP does that, why only PI and not Windows (coming from same public IPv4)?

I see no likely or possible cause. Weird.

I really do not know but after 3 months of searching for similar posts on the internet and tons of frustration I'm not really too fussed right now. I didnt try a VPN as I was sure it couldn't be a throttling issue as my PC was working correctly, so my own fault there for not trying that sooner. The only thing I can really think of is some kind of specific hardware block on my PI, either at the ISP or my usenet provider, if thats even possible and i cant think of one valid reason why any would do such a thing. More likely something in my routers config, but from looking over 3 months, theres nothing obvious that stands out.

I appreciate your help none the less and im happy again for now