Hi there

Could it be that iperf3 is not multithreaded like iperf2 ? We're not able to saturate a 100Gbit Adapter with iperf3 as with iperf2.

It seems that as per Internet search iperf3 should be multithreaded.

We test with iperf3 -s on one host and iperf3 <IP> -P 10 (10 parallel sessions)

Any hints ? Maybe we need to use other options ?

Thanks in advance and kind regards,

Stefano

------------------------------
Stefano Calisto
------------------------------

Hello,

'iperf3 -v' output shows that threading is enabled. is iperf3 is not behaving as compared to iperf2 w.r.t mulithreading ? 

# iperf3 -v
iperf 3.18 (cJSON 1.7.15)
AIX aixoss1-lp6 3 7 000336AA7A00
Optional features available: SCTP, authentication, support IPv4 don't fragment, POSIX threads

Thanks
Ranjit

------------------------------
Ranjit Ranjan

Original Message:
Sent: Tue May 20, 2025 05:46 AM
From: Stefano Calisto
Subject: iperf3 not multithreaded ?

Hi there

Could it be that iperf3 is not multithreaded like iperf2 ? We're not able to saturate a 100Gbit Adapter with iperf3 as with iperf2.

It seems that as per Internet search iperf3 should be multithreaded.

We test with iperf3 -s on one host and iperf3 <IP> -P 10 (10 parallel sessions)

Any hints ? Maybe we need to use other options ?

Thanks in advance and kind regards,

Stefano

------------------------------
Stefano Calisto
------------------------------

Hi there Ranjit

We're not getting the expected throughput we had with iperf2. I'm curious to know if there are others who can confirm this behaviour or proof us wrong and it works as expected.

Thanks and kind regards,

Stefano

------------------------------
Stefano Calisto

Original Message:
Sent: Tue May 20, 2025 06:35 AM
From: Ranjit Ranjan
Subject: iperf3 not multithreaded ?

Hello,

'iperf3 -v' output shows that threading is enabled. is iperf3 is not behaving as compared to iperf2 w.r.t mulithreading ? 

# iperf3 -v
iperf 3.18 (cJSON 1.7.15)
AIX aixoss1-lp6 3 7 000336AA7A00
Optional features available: SCTP, authentication, support IPv4 don't fragment, POSIX threads

Thanks
Ranjit

------------------------------
Ranjit Ranjan

Original Message:
Sent: Tue May 20, 2025 05:46 AM
From: Stefano Calisto
Subject: iperf3 not multithreaded ?

Hi there

Could it be that iperf3 is not multithreaded like iperf2 ? We're not able to saturate a 100Gbit Adapter with iperf3 as with iperf2.

It seems that as per Internet search iperf3 should be multithreaded.

We test with iperf3 -s on one host and iperf3 <IP> -P 10 (10 parallel sessions)

Any hints ? Maybe we need to use other options ?

Thanks in advance and kind regards,

Stefano

------------------------------
Stefano Calisto
------------------------------

Hi there

Could it be that iperf3 is not multithreaded like iperf2 ? We're not able to saturate a 100Gbit Adapter with iperf3 as with iperf2.

It seems that as per Internet search iperf3 should be multithreaded.

We test with iperf3 -s on one host and iperf3 <IP> -P 10 (10 parallel sessions)

Any hints ? Maybe we need to use other options ?

Thanks in advance and kind regards,

Stefano