SMB Sharing - 1000 Mbit down - Only 400 MBit up - Why?

[tonmischa]

Server is a MacMini 2014, latest Monterey, 2 TB SSD, 1 GBit Ethernet, one folder shared via the "Sharing" Pane in System Preferences.
Client is MacStudio, latest Ventura, 10 GBit Ethernet.

When reading from the share I get the full 1 GBit. When writing to the share, I only get ~400 MBit.
Any ideas why? Thank you!


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Things I checked/tried:
- Local Benchmark on the Server's SSD: 530 MByte Read / 520 MByte Write (Sequential)
- SMB encryption is set to off (in nsmb.conf)
- smbutil statshares -a says

USER_ID                       501
SMB_NEGOTIATE                 SMBV_NEG_SMB1_ENABLED
SMB_NEGOTIATE                 SMBV_NEG_SMB2_ENABLED
SMB_NEGOTIATE                 SMBV_NEG_SMB3_ENABLED
SMB_VERSION                   SMB_3.0.2
SMB_ENCRYPT_ALGORITHMS        AES_128_CCM_ENABLED
SMB_ENCRYPT_ALGORITHMS        AES_128_GCM_ENABLED
SMB_ENCRYPT_ALGORITHMS        AES_256_CCM_ENABLED
SMB_ENCRYPT_ALGORITHMS        AES_256_GCM_ENABLED
SMB_CURR_ENCRYPT_ALGORITHM    OFF
SMB_SHARE_TYPE                DISK
SIGNING_SUPPORTED             TRUE
EXTENDED_SECURITY_SUPPORTED   TRUE
UNIX_SUPPORT                  TRUE
LARGE_FILE_SUPPORTED          TRUE
OS_X_SERVER                   TRUE
FILE_IDS_SUPPORTED            TRUE
FILE_LEASING_SUPPORTED        TRUE
MULTI_CREDIT_SUPPORTED        TRUE
DIR_LEASING_SUPPORTED         TRUE
ENCRYPTION_SUPPORTED          TRUE

- Hardware Tab in Network Preferences is set to "Automatic" (server and client)
- Server and client are usually connected via a switch (QNAP QSW-2104-2T). I also connected them directly for testing.
- Different ethernet cable

 

[Bigwaff]

When reading from the share I get the full 1 GBit. When writing to the share, I only get ~400 MBit.

How much data are transferring with tests? Transferring very small files or single large file?

 

[tonmischa]

How much data are transferring with tests? Transferring very small files or single large file?

3 GB single large file. (coming from internal drive of the MacStudio)
It starts off with 100 MByte/sec, then after 2 seconds it goes down to 40 MByte/sec and stays there.

 

[Basic75]

3 GB single large file. (coming from internal drive of the MacStudio)
It starts off with 100 MByte/sec, then after 2 seconds it goes down to 40 MByte/sec and stays there.

How much free RAM does the server have?

 

[Basic75]

How much data are transferring with tests? Transferring very small files or single large file?

And are the read tests reading the same data repeatedly?

 

[tonmischa]

How much free RAM does the server have?

Its a MacMini 2014, i7, 16GB RAM. No open apps, just used as a SMB server.

And are the read tests reading the same data repeatedly?

No, because I wanted to avoid reading the data out of the RAM cache.

 

[Boyd01]

I have a lowly base model 2014 i5 1.4ghz Mini with 4gb RAM. It runs iTunes on Mojave 24/7 with home sharing enabled. I access it regularly from two Apple TV's and other devices. It's connected to my home stereo with speakers in different rooms and I stream Sirius/XM with Safari, also use iTunes to play my own ripped music.

Then I have a top-spec quad 16gb 2012 Mini server that I use as a fileserver and time machine destination. It is running Catalina. Both machines are connected via gigabit ethernet and I did these tests from my 2018 hex i7/64gb Mini on the same network, running Monterey. That machine has 10gb ethernet, but my network is only gigabit.

These suggest that the CPU and RAM aren't really a factor, the test results are the same. The 2014 boots from an older Samsung external SSD that clocks around 400MB/sec, the 2012 has an original internal Apple SSD that clocks around 500MB/sec. Just using the standard MacOS file sharing.

Seems like something else is going on for you, maybe related to the fact that you have 10gb ethernet? Or some other network activity? Maybe Monterey does not play well with your 2014 Mini? Of course, the other big difference is that your client is an Apple Silicon Mac and mine is Intel. I was streaming video with Sling on my iPad on the same network when I did these tests, FWIW.

 

[Boyd01]

FWIW - memory usage on the 2012 Mini

Memory usage on the 2014 Mini

 

[tonmischa]

Seems like something else is going on for you, maybe related to the fact that you have 10gb ethernet? Or some other network activity? Maybe Monterey does not play well with your 2014 Mini? Of course, the other big difference is that your client is an Apple Silicon Mac and mine is Intel.

Thank you for taking the time to do these tests!
I also believe that there are several things going on which might interact with each other. Hard to diagnose...

I have a third Mac in the mix. A 2020 M1 MacMini - also 10 GBit. Just today I had a new problem. While transferring files (each over 1 GB) between the 10GBit MacMini and the 10GBit MacStudio. The speed was fine, but the connection dropped regularly. (It seemed like a faulty cable.) I changed all cables, but nothing changed.

I will now take a closer look at the network switch again. Its a QNAP QSW-2104-2T (2x 10Gbit, 4x 2,5Gbit). One of the "cheaper" 10GBit switches I could find. Maybe I should have not been so cheap...

 

[popup]

This is a comment about QNAP QSW-2104-2T on Amazon:

Using Home NAS with TrueNAS 12-U8 and there is a serious problem with speed...
If I connect the SFP Cisco cable directly between PC and NAS I got full speed both ways. BUT when I connect into this qnap both NAS and PC, then the connection goes to 1GB between NAS -> PC
PC -> NAS is still almost max speed. But NAS to PC goes to 110MB/s instead of atleast 800MB/s.
So be aware of that when purchasing this switch...
About 2.5 Ethernet connections, same thing, can't get above 110MB/s, and I've 10Gb cards.

 

[tonmischa]

This is a comment about QNAP QSW-2104-2T

Thank you for finding this!
I also found this Reddit post talking about the QNAP "killing a network".

I have now switched to an older 1 GBit Zyxel switch and will check for a few days.
(I was pretty sure I had tried a direct connection between client and server and ruled out the switch as the culprit... Oh well...)

 

[Kgeee]

I always test network speeds with iPerf3 first. This takes any problems with disk speed out of the equation.