Interrupt Moderation setting on network interface

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w-u-2-o
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Interrupt Moderation setting on network interface

Postby w-u-2-o » Mon Jan 24, 2022 9:06 pm

Here's an interesting one: on my Intel network interface card (NIC) I was doing some speed testing using iperf and was shocked to see the card only moving 150 Mbit/s. This is on a dual NIC, server type, PCIE card, and an i7 CPU, so it should be quite a bit faster.

After poking around in the advanced settings of the network adapter, I found that when I turned off "interrupt moderation" the transfer rate went up to 930Mbit/s! Needless to say I was quite pleased!

I'm not sure this has any real bearing on the performance of our radios, but I'd rather have a faster card than a slower card.

BTW, the challenge for this kind of testing is to have the iperf server running on something you trust to be faster than the PC you are testing. I installed iperf on my QNAP NAS server that has a 2Gbit connection to my switch and that worked quite well as a trusted server platform.
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Tony EI7BMB
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Re: Interrupt Moderation setting on network interface

Postby Tony EI7BMB » Wed Jan 26, 2022 4:04 pm

Found some suggested ethernet settings on this page from Flex https://helpdesk.flexradio.com/hc/en-us ... erformance
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Re: Interrupt Moderation setting on network interface

Postby oe3ide » Wed Jan 26, 2022 7:19 pm

Very interesting, Scott.
Funny thing: I have here 6 different PCs in my network... I started the tests on my htpc in the livingroom and noticed 97Mbit :o
Some quick checks (cable, switch) revealed a NIC issue, so I replaced the NIC and all is fine now (961 MBit), Maybe I wouldn't have figured it out without your post :lol:

Just made some tests on all my clients. Speed is ~960MBit. Here on my environment this setting does not change the speed at all.

73 Ernst
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w-u-2-o
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Re: Interrupt Moderation setting on network interface

Postby w-u-2-o » Wed Jan 26, 2022 9:33 pm

Tony EI7BMB wrote:Found some suggested ethernet settings on this page from Flex https://helpdesk.flexradio.com/hc/en-us ... erformance
I don't agree with all those settings, but it's a pretty good list, nonetheless. I'd leave buffer sizes at stock settings and, unless your CPU is very highly utilized, leave all offloading settings turned on. However any differences should be quite minimal either way.

Another thing that I've had good results with, if you have a dedicated NIC that is only connected to the ANAN, is to go into the properties for that dedicated, single purpose NIC adapter and turn off ALL services EXCEPT for IP4 and PCAP. You could even turn off PCAP (if installed) but then Bootloader won't work when you need it.
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Tony EI7BMB
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Re: Interrupt Moderation setting on network interface

Postby Tony EI7BMB » Thu Jan 27, 2022 9:25 am

Will try your suggestion Scott and turn off unused item on the dedicated NIC for the Anan. This NIC is still showing as a public network even though I've changed it in the registry to private, any suggestions on that ?
W4WMT
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Re: Interrupt Moderation setting on network interface

Postby W4WMT » Thu Jan 27, 2022 10:20 am

Hi Scott,

Now that you have replaced that two-port PCIe NIC, you should try and repeat your experiment on the "Interrupt Moderation" setting to see if you get the same results as before?

73, Bryan W4WMT
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w-u-2-o
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Re: Interrupt Moderation setting on network interface

Postby w-u-2-o » Thu Jan 27, 2022 1:07 pm

Tony EI7BMB wrote:Will try your suggestion Scott and turn off unused item on the dedicated NIC for the Anan. This NIC is still showing as a public network even though I've changed it in the registry to private, any suggestions on that ?

I have no idea. I don't mess with registry settings like that. I would guess, however, that this is a firewall rules issue. You might change your registry back to stock and look at the Windows Defender firewall setup instead.
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w-u-2-o
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Re: Interrupt Moderation setting on network interface

Postby w-u-2-o » Thu Jan 27, 2022 1:10 pm

W4WMT wrote:Hi Scott,

Now that you have replaced that two-port PCIe NIC, you should try and repeat your experiment on the "Interrupt Moderation" setting to see if you get the same results as before?

73, Bryan W4WMT

Very insightful! I didn't think of trying that!

And, as I suspect you are expecting me to report, the new NIC works 100% fine, super-fast, with Interrupt Moderation turned back on.

Interesting! Perhaps a good indicator of bad NIC in general?
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Re: Interrupt Moderation setting on network interface

Postby Tony EI7BMB » Thu Jan 27, 2022 11:43 pm

w-u-2-o wrote:
Tony EI7BMB wrote:This NIC is still showing as a public network even though I've changed it in the registry to private, any suggestions on that ?

I have no idea. I don't mess with registry settings like that. I would guess, however, that this is a firewall rules issue. You might change your registry back to stock and look at the Windows Defender firewall setup instead.


Found the answer to change network type here https://www.itechtics.com/change-networ ... indows-10/

I used method 3 "3- How to change Network Type using Local Security Policy"
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Re: Interrupt Moderation setting on network interface

Postby W4WMT » Fri Jan 28, 2022 12:53 am

w-u-2-o wrote:And, as I suspect you are expecting me to report, the new NIC works 100% fine, super-fast, with Interrupt Moderation turned back on.


Ha! No expectations here. Just curious, that's all :-)
73!

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