Windows 11 Bogged Down

[FarangFlix]

sabnzbd 4.1.0 on Windows 11

Just recently, running sabnzbd really bogs down my desktop. It effects all aspects from word processing to File Explorer with really slow responses. Pausing eliminates this problem.

Download speeds are what is to be expected. CPU usage is normal at around 40-50% average. No disk space issues or memory leaks.

I'm clueless. Help?

[sander]

While SAB is not doing anything:

In SABnzbd's upper right corner, click on the wrench symbol ("Status and interface options"), then click on first tab Status, and there click on the Refresh Arrow. Post the values of the lower part here.

[FarangFlix]

I'm not sure this is the information you're asking for but here is what I got.

Local IPv4 address 192.168.1.2
Public IPv4 address xxx
IPv6 address xxx
Nameserver / DNS Lookup OK
Used cache 630.9 MB (892 articles)
System performance (Pystone) 0 AMD Ryzen 7 5700G with Radeon Graphics AVX2
Download folder speed 0 MB/s C:\sabnzbd-downloads\incomplete
Complete folder speed 0 MB/s C:\sabnzbd-downloads\complete
Internet Bandwidth 0 MB/s 0 Mbps

[sander]

Wow. Pystone of 0. Disk speed 0.

Two possible causes:
1) your system is totally FUBAR
2) you did not read / execute my instruction, especically the part "and there click on the Refresh Arrow. "

[FarangFlix]

I did. on the upper right of the box. There are actually 5 buttons on that window but only 1 labeled "Refresh" on the upper right next to the X button. Was there a different button you wanted me to press? I always consider myself as following instructions as given. This may be a case of GIGO

[sander]

The refesh symbol inside that wrench popup ... so the circled arrow

[FarangFlix]

I'm guessing you mean the "Repeat Test Arrow" instead of the "Refresh Arrow?" Sorry about that. I tend to follow instructions given instead of guessing which instructions were meant to be. Here's the results...

Local IPv4 address xxx
Public IPv4 address xxx
IPv6 address xxx
Nameserver / DNS Lookup OK
Used cache 104.0 MB (121 articles)
Download speed limited by Disk speed (358x)
System performance (Pystone) 538618 AMD Ryzen 7 5700G with Radeon Graphics AVX2
Download folder speed 75.7 MB/s C:\sabnzbd-downloads\incomplete
Complete folder speed 55.2 MB/s C:\sabnzbd-downloads\complete
Internet Bandwidth 13.5 MB/s 108 Mbps

[sander]

CPU: a beast
Disk: slow! What kind of disk is that? An ol spinning HDD?
Internet speed: is 100 Mbps what you buy from your ISP?

EDIT:

Download speed limited by Disk speed (358x) ... there you have it. Not good.

[FarangFlix]

I have a Samsung 2TB SSD drive. I'll switch the directory to a different drive if you think that's the issue.

[sander]

You can try.

An SSD should yield 250 - 500 MB/s. And a NVMe 1000 - 3000 MB/s

Not the 75 MB/s you get.

EDIT:

If SABnzbd experiences a slow disk, it can also be caused by a virusscanner that stall the effective write speed to disk. Workaround: exclude the SABnzbd Temp/Incomplete directory from scanning by your virusscanner.

[dwells]

It does seem that there's some sort of issue with SABnzbd and Windows 11 that has existed since a Windows update several months ago. Like the user in this thread has reported, as well as a few other support threads on here, my system is getting absolutely slammed with 100% disk usage and coming to a total halt during downloads. Here's the spec test results:

Code: Select all

Download speed limited by  Disk speed (64x)
System performance (Pystone)  685405  13th Gen Intel(R) Core(TM) i5-13600K AVX2
Download folder speed  1514.9 MB/s  C:\Users\winusernamehere\Downloads\Usenet\Incomplete
Complete folder speed  1544.5 MB/s  C:\Users\winusernamehere\Downloads\Usenet

Those folder speeds are actually a bit slower than real world as CrystalDiskMark and similar report a bit over double that, but nonetheless it's definitely sufficient. CPU is running stock clocks and confirmed stable through stress testing, 32GBs of stability-verified DDR4 3200 as well, so as far as specs go there's no issue in that department. So far I've tried disabling Direct Unpack, which mostly resolves the sawtooth download speed pattern issue but not always; occasionally it'll spike disk usage anyway and thus download speed comes to a crawl.

If SABnzbd experiences a slow disk, it can also be caused by a virusscanner that stall the effective write speed to disk. Workaround: exclude the SABnzbd Temp/Incomplete directory from scanning by your virusscanner.

Here's Windows Defender > Virus & threat protection settings > Exclusions >

Code: Select all

C:\Users\winusernamehere\Downloads\Usenet
Folder

C:\Users\winusernamehere\Downloads\Usenet\Incomplete
Folder

Worth mentioning is that when it does spike disk usage to 99%/100%, the actual read/write speeds aren't even close to maxing out the NVMe according to Task Manager and tend to be in the 50 MB/s range, as if the disk is just getting repeatedly smacked with a bunch of little queries clogging it up instead of a sustained operation.

I've tested unpacking large multi-part .rar files in the Usenet folder manually when SAB isn't running using 7zip and NanaZip (UWP 7zip fork), and the unpacking behaves like you'd expect with fast writes and no system-halting disk hammering. But those same ones seem to be an issue when downloaded and processed with SABnzbd. The main difference I can think of is that SAB has to deal with assembling the articles and deal with deobfuscation, so perhaps that's where things are going wonky.

At any rate, something is going on here, and it seems to be specific to SABnzbd with Windows 11 and how it's interacting with files. There's no doubt in my mind here that the fault lies with Microsoft having tweaked something to do with Windows 11 and disk/file handling that's triggering the bad behavior with SAB, but nonetheless it would be nice to find some sort of solution here.

@sander: let me know if you'd like logs or anything like that, as I'm happy to do whatever I can to help track this down and get it fixed!

[sander]

Code: Select all

Download speed limited by  Disk speed (64x)

So ... not a real bottleneck? At least ... after how many GBs of downloads was this?
Restart SABnzbd, and do the 10GB test download ... what is the limited-by then? And what is the download speed?

Code: Select all

System performance (Pystone)  685405  13th Gen Intel(R) Core(TM) i5-13600K AVX2
Download folder speed  1514.9 MB/s  C:\Users\winusernamehere\Downloads\Usenet\Incomplete
Complete folder speed  1544.5 MB/s  C:\Users\winusernamehere\Downloads\Usenet

What a beast!

If with such a beast things feel slow, it's something in the OS. You won't find much in sabnzbd.log. You should use tools in/for Windows (during a SAB download) to find out what is going. I don't think you will find useful info in sabnzbd.log. And I don't use Windows, so I can't help you with Windows tools.

[dwells]

So ... not a real bottleneck? At least ... after how many GBs of downloads was this?
Restart SABnzbd, and do the 10GB test download ... what is the limited-by then? And what is the download speed?

Only because direct unpack is turned off, if it's left on then the download will bounce back and forth between full speed and periods of near-zero as the disk becomes completely locked after a minute or so of starting the download. Had this been a larger download (20GB+), it would have started to slow down pretty badly and have similar behavior, even with direct unpack off.

If with such a beast things feel slow, it's something in the OS. You won't find much in sabnzbd.log. You should use tools in/for Windows (during a SAB download) to find out what is going. I don't think you will find useful info in sabnzbd.log. And I don't use Windows, so I can't help you with Windows tools.

The issue has something to do with the unpacking process. Take a look here at what happens once SABnzbd starts unpacking the test file. You can see it managed to download at full speed without issue, but once unpacking starts, things go south. The system's disk has been almost completely locked and response times range from 500 to 2000 ms, with 99% or 100% disk usage despite the write speeds being a tiny fraction of what this drive is capable of. In fact, things are so bad that the SAB interface even loses connection with itself during the postprocessing (or during the download if direct unpack is left on).



I can recreate this on other systems as well with different processors and SSDs, which are also running Windows 11 and also have the download folders excluded from the basic built-in Windows AV system. I know you mentioned you don't use Windows, but maybe spin up a Windows 11 VM and give it a try just to see if you can recreate this as well?

I do think the fault lies with Windows here, I'm just hoping some of the team here can help figure out a workaround since it does seem to be impacting at least a handful of users.

[safihre]

Have you check for driver updates?
I have windows 11 myself and a gigabit connection, but I don't see this. I even have some slow regular ssd.

[dwells]

Have you check for driver updates?
I have windows 11 myself and a gigabit connection, but I don't see this. I even have some slow regular ssd.

Interesting, is Windows Defender AV turned on, or do you have it completely disabled? Drivers are updated, even tried switching from the Intel NVMe drivers to the newer Solidigm ones since they took over Intel's SSD operations, but no change.

I'll have to go try the other machine again that was exhibiting similar symptoms and see if the behavior has any differences at all.