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Slow folder speed with SSD and U.2

Posted: January 28th, 2025, 5:01 pm
by jokri88
Hi, im running sab in a proxmox vm.
My Downloaddisk I attach as virtual disk, and it's an SSD (Intel S4610).
Im only getting this speeds for folder:

1.40 | 1.27 | 0.68 | V=2743M R=154M
System Performance (Pystone) 443750 AMD EPYC 7713 64-Core Processor AVX2
Download folder speed 255.1 MB/s
Complete folder speed 249 MB/s
Internet Bandwidth 242.6 MB/s 1940.8 Mbps



With my U.2 I get:
1.40 | 1.27 | 0.68 | V=2743M R=154M
System Performance (Pystone) 443750 AMD EPYC 7713 64-Core Processor AVX2
Download folder speed 652.4 MB/s
Complete folder speed 641 MB/s
Internet Bandwidth 242.6 MB/s 1940.8 Mbps

It's still way too slow for an U.2 and the SSD. Anybody an idea what could be wrong here?

Re: Slow folder speed with SSD and U.2

Posted: January 29th, 2025, 1:22 am
by sander
Why is it a problem for you?

If you go into SABnzbd proxmox VM, what is the output of the command below, but with of pointing to your virtual drive?

Code: Select all

$ for i in {1..10}; do dd if=/dev/zero of=bla.bin bs=1M count=1 2>&1 | grep MB; done
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00357261 s, 294 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.0034286 s, 306 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00238313 s, 440 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00308719 s, 340 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00322151 s, 325 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00263795 s, 397 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00317071 s, 331 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00355366 s, 295 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00352931 s, 297 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00346856 s, 302 MB/s

Re: Slow folder speed with SSD and U.2

Posted: January 29th, 2025, 3:35 am
by jokri88
sander wrote: January 29th, 2025, 1:22 am Why is it a problem for you?

If you go into SABnzbd proxmox VM, what is the output of the command below, but with of pointing to your virtual drive?

Code: Select all

$ for i in {1..10}; do dd if=/dev/zero of=bla.bin bs=1M count=1 2>&1 | grep MB; done

This is the output for the SSD:
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00344411 s, 304 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00187032 s, 561 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00193652 s, 541 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00187253 s, 560 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00180773 s, 580 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00193718 s, 541 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00196069 s, 535 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00186264 s, 563 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00211453 s, 496 MB/s
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00190174 s, 551 MB/s
I have mostly the problem that my download is slowed down from the disk, thats why i wondering about the slow folder speed in sab.

Re: Slow folder speed with SSD and U.2

Posted: January 29th, 2025, 4:11 am
by sander
"1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00344411 s, 304 MB/s"

So the first write is the same speed as SABnzbd experiences it, right?

SABnzbd writes a lot of small files (1MB or smaller).

"I have mostly the problem that my download is slowed down from the disk, thats why i wondering about the slow folder speed in sab."

What might help: put SAB's Temp/Incomplete inside the VM. Not mapped onto a drive outside the VM or docker.

Re: Slow folder speed with SSD and U.2

Posted: January 29th, 2025, 6:19 am
by jokri88
sander wrote: January 29th, 2025, 4:11 am "1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00344411 s, 304 MB/s"

So the first write is the same speed as SABnzbd experiences it, right?

SABnzbd writes a lot of small files (1MB or smaller).

"I have mostly the problem that my download is slowed down from the disk, thats why i wondering about the slow folder speed in sab."

What might help: put SAB's Temp/Incomplete inside the VM. Not mapped onto a drive outside the VM or docker.
304MB/s is higher than what SAB is showing. SAB maximum is around 260MB/s.

The SSD is attached to the VM directly through proxmox, its nothing outside or docker.

Re: Slow folder speed with SSD and U.2

Posted: January 29th, 2025, 6:57 am
by sander
It is what SABnzbd experiences.

I think you have enough knowledge and handles to explore it further.