Strange and slow networking behaviors

[1eo]

Alright context.

I have 2 nodes in a cluster.
Dell R620
Dell R720

Going to talk about 3 devices total. All have 10Gb networking to each other through a switch

Both machines are running the same pve version (8.1.10) and kernel versions, both are fully up to date
Both machines have the same networking setup per say
Both machines have the same model of boot devices
Both machines have similar levels of cpu usage

All of these tests were using iperf3

Test cases:
Pc - R720
My pc running as the client to the r720 running as the server. I get around 5Gb. Which is not correct.
My pc running as the server and the r720 running as client i get 10Gb. Which is correct

Pc - R620
My pc running as the client to the r620 running as the server. I get around 10Gb. Which is correct.
My pc running as the server and the r620 running as client i get 10Gb. Which is correct.


R620 - R720
R620 running as the client to the r720 running as the server. I get around 5Gb. Which is not correct.
R620 running as the server and the r720 running as client i get 10Gb. Which is correct

I have tried a different port on the same nic on the 720 with the same results with it being slow one direction but completely fine the other

Im massively confused on why this is happening. Both the R620 and R720 are using the same network cards


Thanks
Leo

 

[_gabriel]

isn't the r720 has a lower cpu single thread score ?
iperf3 is single thread application.

 

[1eo]

isn't the r720 has a lower cpu single thread score ?
iperf3 is single thread application.

The 720 has v2 cpus and the r620 has v1 cpus

 

[_gabriel]

with model we can check Specs.

 

[1eo]

isn't the r720 has a lower cpu single thread score ?
iperf3 is single thread application.

If you want the models

E5-2690 v1 x2 r620. According to https://cpubenchmark.net Single core 1662​

E5-2650 v2 X2 r720 According to https://cpubenchmark.net Single core 1690​

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[1eo]

Also the network cards in both are

Broadcom 57800​

 

[_gabriel]

as think it's expected.
2690 has 3,8 GHz and 135W while 2650 has 3,4 GHz and 95W.
have you tried with mitigations=off ?
have you used iperf3 parallel connections ?
try with iperf2

 

[1eo]

as think it's expected.
2690 has 3,8 GHz and 135W while 2650 has 3,4 GHz and 95W.
have you tried with mitigations=off ?
have you used iperf3 parallel connections ?
try with iperf2

This is not just with iperf this also reflects in smb transfer speeds


I don't think it's the CPUs as by the looks of it the 2650v2 is slightly faster and that's in the 720

My main issue is why can I download from the server at a really fast speed but I can't upload to the server at a fast speed