Slower SAB DL After Internet Speed Upgrade

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sundialexpress
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Slower SAB DL After Internet Speed Upgrade

Post by sundialexpress »

Had 200 Mbit (megabits per second) connection and could max downloads with SAB Docker in unRAID at 23-24 MB/s (megabytes per second). I increased my internet plan to a 400 Mbit connection. Now maximum downloads with SAB are less than 20 MB/s. Doubling my internet speed I would have expected to see downloads at greater than the 23-24 MB/s that I was seeing initially.

Hardware: Dual Xeon LGA 1366 @ 2.27 Ghz, w/ 48 GB ECC RAM, gigabit ethernet port

Pystone Test: 83,153
Download Folder Speed: 124.9 MB/s
Complete Folder Speed: 124.7 MB/s

iPerf Home Network Test: 940 Mbit/s between server and router

1000 MB SAB DL Test: same download behavior as below, a ramp up to 25 MB/s with immediate drop to 10 MB/s or so.

Additional Behavior: Now when initiating downloads in SAB, I usually see the DL ramp up fairly quickly to a high number but quickly drop and taper off to something slow. For example, I might see an initial ramp up to 25 MB/s, with an almost immediate drop to 10 MB/s. If I pause the download, I'll often see a spike in the reported download speed in SAB as high as 45 MB/s. But I am never able to actually download at those higher speeds.

Before the internet upgrade, download behavior looked like this: initiate download in SAB and see an initial ramp up to 23 MB/s and then speeds hover around 22-24 MB/s. Sometimes a drop would occur for expected reasons, such as high cpu use during a file repair, or missing blocks in the download. But that's normal and expected.

Alternate SAB: I installed SAB on my laptop and am able to download through a wired gigabit ethernet port on my network at 50 MB/s.

Thank you in advance,.

What is going on?
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sander
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Re: Slower SAB DL After Internet Speed Upgrade

Post by sander »

sundialexpress wrote: March 16th, 2019, 6:01 pm
Alternate SAB: I installed SAB on my laptop and am able to download through a wired gigabit ethernet port on my network at 50 MB/s.

That is interesting ...

What if ... you run SAB with a fresh ini file on your Xeon machine. So something like "sabnzbd -f my-test-sab.ini". And then the same settings as on your laptop. So probably as little settings as possible.
sundialexpress
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Joined: March 16th, 2019, 5:31 pm

Re: Slower SAB DL After Internet Speed Upgrade

Post by sundialexpress »

I deleted the docker, docker image, and all application data, and then reinstalled SAB docker. Left default install settings. Added one server with the same number of connections. No improvement. When I pause a download, the speed jumps up to 35 MB/s momentarily before going to zero. It's almost as if there is 35 MB/s availability but something is causing a bottleneck.
sundialexpress
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Re: Slower SAB DL After Internet Speed Upgrade

Post by sundialexpress »

So, I've been racking my brain trying to figure out "why" SAB Docker in unRAID slowed down. To reiterate, when I had a 200 Mbit connection, I could saturate DL 22-24 MB/s over VPN even. After upgrading to 400 Mbit, my SAB DL dropped significantly.

Last night I revisited server tuning, and pinned CPU cores to SAB Docker. I started with two hyperthreads last night. No change. This morning, I added two more hyperthreads, and now with four hyperthreads pinned to SAB, I at least get 20-25 MB/s DL. I'll try pinning two more to see if there is further improvement.

Additionally, with four pinned hyperthreads the DL speeds no longer dip when SAB unpacks.
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sander
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Re: Slower SAB DL After Internet Speed Upgrade

Post by sander »

sander wrote: March 17th, 2019, 2:10 am
sundialexpress wrote: March 16th, 2019, 6:01 pm
Alternate SAB: I installed SAB on my laptop and am able to download through a wired gigabit ethernet port on my network at 50 MB/s.

That is interesting ...

What if ... you run SAB with a fresh ini file on your Xeon machine. So something like "sabnzbd -f my-test-sab.ini". And then the same settings as on your laptop. So probably as little settings as possible.
What I meant: can you run SAB with a fresh ini file on your Xeon machine WITHOUT DOCKER. So on the OS itself.

Reason: rule out docker.

(FWIW: I wonder if docker can have the same delay as VM's due to the NAT-layer in VM, in combination with SAB's reading mechanism if #connections >= 8 . I tried for myself, and i both cases I get a nice 68 MB/s, but I wonder about your setup )
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