Re: RN102 slow performances

Tibonhomme · ‎2024-09-10

Hey there !

Just found out an old RN102 that seem to work, I'm trying to set it up 🙂

I am surprised however as it seems too slow compared to the expected capabilities.

I've been trying to upload different files to test it's speed, and i seem to be stuck at ~9 MB/s

I obtained this value by two different means : Trough the windows explorer (using the network), and trough the web interface.

I am not directly wired to the internet from the computer, I have a mesh wifi installed. So the computer is in wifi but the NAS is directly wired. I tried to speedtest my internet connection from the computer and got 145 mb/s for the download and 135 mb/s for the upload, so I would expect at least 15MB/s for the NAS (if im not wrong).

My HDD is entirely knew and is a 7200RPM connected with SATA that should give me at least 220 MB/s. I tried replacing it with a slower and older one but got about the same transfer time.

The NAS Version is 6.10.10

Could someone help me please ? Am I thinking this wrong ?

Many thanks !

Kev'

StephenB · ‎2024-09-16

@Tibonhomme wrote:

it is set right now to 1 Gb/s and not 1 GB/s, could that be the problem ?

No, this is correct.

B is Bytes
b is bits

so 1 gigabit per second.

You can't set this in the NAS, it is negotiated by the NAS and whatever device it is connected to.

@Tibonhomme wrote:

All right I see, but wouldnt that mean the reading speed should be significantly higher ?

It depends on the details.

With SMR drives, the tracks are so close together that when you write to track X, you overwrite X+1. Periodically there is extra space (separating the platter into zones).

So when you write to track x, the drive firmware needs to

read track x+1
write track x
read track x+2
write track x+1
...

until it reaches the end of the zone.

These drives do have a large cache, and they will re-order writes to try to minimize the amount of "rippling" that is needed. But at some point the cache isn't enough, and the performance can become glacially slow (often a lot slower than what you are seeing in the test).

Even when the cache is sufficient, there often is a lot of background "rippling" that needs to be done after your writes finish. Even though that is done in the background, the extra seeks can also slow read speed.

The 15 MB/s speeds you measured are equivalent to about 120 Mb/s (8 bits per byte). That is about the internet speed you measured with Speedtest.

Was this last test done with the PC connected with ethernet? If so, was the ethernet directly connected to the same mesh element as the NAS? Or were you using the mesh wifi backhaul?

View solution in original post

StephenB · ‎2024-09-10

What model hard drive?

Have you checked the link speed of the NAS ethernet (either using ssh or looking at the connection in your router)?

Have you tried a different ethernet cable?

saudade · ‎2024-09-11

Also consider the read/write speeds of the drives. Are you uploading a single large file or many small ones?

Is the NAS connected directly to a mesh unit, or through some other hub/switch? What category are the cables are you using?

Sandshark · ‎2024-09-11

"Slow" in what way? The 102 and 104 are the most CPU and RAM limited of the OS6 native NAS and >10 years old. So they are slower than most.

StephenB · ‎2024-09-11

@Sandshark wrote:

"Slow" in what way? The 102 and 104 are the most CPU and RAM limited of the OS6 native NAS and >10 years old. So they are slower than most.

@Tibonhomme says ~9 Mb/s transfer speed.

Not sure if that is for large file transfers or a lot of small files though. If it is when transfering > 1 GB files then something is definitely wrong.

Tibonhomme · ‎2024-09-11

Hey there,

First of all thank you all for your answers.

Here is the link to the new hard drive i am using :

https://www.digitec.ch/en/s1/product/seagate-barracuda-2-tb-35-cmr-hard-drives-9302108?ip=HDD+barrac...

I am trying to move large file and not large collection of small files (with which a slower transfer speed would be understandable). For example I am moving movies larger than a GB.

I tried changing the ethernet cable with another one but got the same result. The cable I am trying is a 5e category RJ45 so I wouldn't expect it to be the bottleneck reason.

I am not sure on how to check "the link speed of the NAS ethernet (either using ssh or looking at the connection in your router)?" however, do you got any specific instruction that could help me please ?

Thanks !

Kevin.

Tibonhomme · ‎2024-09-11

For the record I was suspicious that the wireless part of my network could be the source of the problem si i wired my computer to the same wifi-mesh node that is connected to the NAS and got about the same result (an average of 10 MB/s).

Also I saw on some treads that the MTU could have an impact so I made sure it was set at 1500 for both my computer and the NAS settings.

StephenB · ‎2024-09-11

@Tibonhomme wrote:

https://www.digitec.ch/en/s1/product/seagate-barracuda-2-tb-35-cmr-hard-drives-9302108?ip=HDD+barrac...

While current 1 TB Barracuda drives are CMR, the other sizes (2-8TB) are all SMR. Can you provide the actual drive model? You can see this by going into the NAS web ui, selecting system->volumes, and then hover your mouse over the drive.

This screen shot comes from my own RN102 (which has 1 TB Seagate Ironwolf drives)

One package you can use to test the transfer speed is a program called NasTester

https://www.700c.dk/?code-csharp-nas-performance

When I test this using a 1 GB file size on my own RN102 I get read speeds around 53 MB/s and write speeds around 71 MB/sec.

Running warmup...
Running a 1000MB file write on \\10.0.0.13\Videos 5 times...
Iteration 1:     69.75 MB/sec
Iteration 2:     71.17 MB/sec
Iteration 3:     70.93 MB/sec
Iteration 4:     71.71 MB/sec
Iteration 5:     71.33 MB/sec
-----------------------------
Average (W):     70.98 MB/sec
-----------------------------
Running a 1000MB file read on \\10.0.0.13\Videos 5 times...
Iteration 1:     53.18 MB/sec
Iteration 2:     53.38 MB/sec
Iteration 3:     53.64 MB/sec
Iteration 4:     53.30 MB/sec
Iteration 5:     53.19 MB/sec
-----------------------------
Average (R):     53.34 MB/sec

10 MB/sec suggests that the ethernet link might somehow negotiating 100 mbps ("fast") ethernet instead of gigabit. You can see the negotiated speed on the NAS by going to the network page in the NAS admin web ui. You'll see a "Bandwidth" field at the bottom left of the page.

But another possibility (particularly for write performance) is that the drive is in fact SMR.

Tibonhomme · ‎2024-09-15

Hey there,

I apologies for the late answer.

Hre is the actual model of the disk, which is the 2TB (so an SMR one, and i didnt actually looked up that spec before buying it).

Please excuse the UI being in french i didnt found how to make it engligh ^^ maybe with your own capture you may compare the fields to understand it ?

The indicated bandwith in the network tab is "1GB/s" (under the ipv4 and 6 adresses) so i assume this wouldnt be the problem here...

I'm not very familiar with CMR Vs SMR differences, how would that change the actual speed ?

Many thanks ! Have a nice day !

Kev'

Tibonhomme · ‎2024-09-15

Im sorry I forgot,

I also ran the NAS performance tester with a 1000MB file. I had slightly better result than usual (maybe because im home alone so less trafic ?), but nothing crazy.

Running warmup...
Running a 1000MB file write on \\NAS-TIBONHOMME\VolumeMain 5 times...
Iteration 1:     16,08 MB/sec
Iteration 2:     15,32 MB/sec
Iteration 3:     13,91 MB/sec
Iteration 4:     15,53 MB/sec
Iteration 5:     15,50 MB/sec
-----------------------------
Average (W):     15,27 MB/sec
-----------------------------
Running a 1000MB file read on \\NAS-TIBONHOMME\VolumeMain 5 times...
Iteration 1:     13,84 MB/sec
Iteration 2:     14,44 MB/sec
Iteration 3:     13,94 MB/sec
Iteration 4:     14,53 MB/sec
Iteration 5:     13,99 MB/sec
-----------------------------
Average (R):     14,15 MB/sec
-----------------------------

StephenB · ‎2024-09-15

The SMR drive can have very slow write performance, and once the cache is overrun read performance will also suffer. It might be worth trying a smaller file size.

Have you checked the ethernet link speed on the NAS network page?

Tibonhomme · ‎2024-09-16

All right I see, but wouldnt that mean the reading speed should be significantly higher ? It's not the case right now they're about the same speed.

If you're talking about this, it is set right now to 1 Gb/s and not 1 GB/s, could that be the problem ? I cant select it from the settings page of this network tab.

StephenB · ‎2024-09-16

@Tibonhomme wrote:

it is set right now to 1 Gb/s and not 1 GB/s, could that be the problem ?

No, this is correct.

B is Bytes
b is bits

so 1 gigabit per second.

You can't set this in the NAS, it is negotiated by the NAS and whatever device it is connected to.

@Tibonhomme wrote:

All right I see, but wouldnt that mean the reading speed should be significantly higher ?

It depends on the details.

With SMR drives, the tracks are so close together that when you write to track X, you overwrite X+1. Periodically there is extra space (separating the platter into zones).

So when you write to track x, the drive firmware needs to

read track x+1
write track x
read track x+2
write track x+1
...

until it reaches the end of the zone.

These drives do have a large cache, and they will re-order writes to try to minimize the amount of "rippling" that is needed. But at some point the cache isn't enough, and the performance can become glacially slow (often a lot slower than what you are seeing in the test).

Even when the cache is sufficient, there often is a lot of background "rippling" that needs to be done after your writes finish. Even though that is done in the background, the extra seeks can also slow read speed.

The 15 MB/s speeds you measured are equivalent to about 120 Mb/s (8 bits per byte). That is about the internet speed you measured with Speedtest.

Was this last test done with the PC connected with ethernet? If so, was the ethernet directly connected to the same mesh element as the NAS? Or were you using the mesh wifi backhaul?

Tibonhomme · ‎2024-09-19

Hello there ! I apologize for the late answer took me some time to find a laptop in order to proceed to today's experiment.

First of all thank you very much for your detailed explaination of the disk way of working, i appreciate it 🙂

So the last NAStester log was made from a PC in my room using the wifi trough the mesh element to get to the NAS (the wifi mesh element and the NAS are wired).

As you said there was a matching speed between the speed of actual writing and the connection speed i measured with a speed test.

So today i brought in a laptop on which i ran NAStester again, but this time directly wired to the wifi mesh element (and so, not directly, but wired to the NAS too because again my mesh element and the NAS are wired together), and this time got much much higher speed.

Running warmup...
Running a 1000MB file write on \\NAS-TIBONHOMME\VolumeMain 5 times...
Iteration 1:     78.38 MB/sec
Iteration 2:     75.63 MB/sec
Iteration 3:     77.23 MB/sec
Iteration 4:     75.94 MB/sec
Iteration 5:     77.71 MB/sec
-----------------------------
Average (W):     76.98 MB/sec
-----------------------------
Running a 1000MB file read on \\NAS-TIBONHOMME\VolumeMain 5 times...
Iteration 1:     57.37 MB/sec
Iteration 2:     56.14 MB/sec
Iteration 3:     54.32 MB/sec
Iteration 4:     48.07 MB/sec
Iteration 5:     56.59 MB/sec
-----------------------------
Average (R):     54.50 MB/sec
-----------------------------

I used both time the same size of file (1000MB) and the difference is really significant, so after all the element that was indeed the source of this bottleneck was the wireless part between my PC and the wifi mesh element !

StephenB · ‎2024-09-19

@Tibonhomme wrote:

So today i brought in a laptop on which i ran NAStester again, but this time directly wired to the wifi mesh element (and so, not directly, but wired to the NAS too because again my mesh element and the NAS are wired together), and this time got much much higher speed.

the element that was indeed the source of this bottleneck was the wireless part between my PC and the wifi mesh element

Now you are getting about the same speeds that I got in my test (which also used a NAS connected with ethernet).

How old was the original laptop? Your 15 MB/s speeds are about what I'd expect for an 802.11n connection.

Tibonhomme · ‎2024-09-19

Hey,

It was not a laptop but a desktop computer with a usb wifi antenna

After checking its specs it is exactly 802.11n, I didnt thinked about it at all but you make me realize that I could significantly increase my internet speed too by buying a new one !