Best Ethernet Cards for Streaming

[The Computer Audiophile]

1 hour ago, TomJ said:

I had also requested here in with the forum owner an article concerning the topic Ethernet sound with my measurements, on this unfortunately then no more answer received.

Just to make sure people have the facts. Here is my response to your message. At the time, the article concept wasn’t very clear in my head, but I was clearly interested in the topic. I was interested in your findings, but had no clue what you’d found or how you tested anything. 

 

[TomJ]

Just to make sure, this is not the hole story , here my 2 unanswered answers (last May 7) to your posted message - but i don't want to argue with you, but rather discuss the results of my findings.

 

 

 

 

[Jud]

5 hours ago, TomJ said:

Hi guys,

 

my summary of the measurements of the EtherREGEN are currently published:
https://www.open-end-music.com/forum/pr ... post658415

 

I also measured the EtherREGEN with an external 10MHz clock to see if there is really any improvement on this.

 

I had also requested here in with the forum owner an article concerning the topic Ethernet sound with my measurements, on this unfortunately then no more answer received.
So you have to read the article with Google Translate and maybe accept small translation errors.

 

Best regards and happy reading,

 

Tom

 

The link is incomplete, and your next two messages have pictures of links rather than the links themselves. I tried searching for your summary in the forum but was unable to find it. Would you be kind enough to provide the full link? Thanks.

[TomJ]

https://www-open--end--music-com.translate.goog/forum/privatforen/thomas-michael-rudolph-tmr/651284-messungen-von-ethernet-infrastruktur-nur-lesen/page2?_x_tr_sl=de&_x_tr_tl=en&_x_tr_hl=de&_x_tr_pto=wapp#post658415

 

Hope this works now!

 

There is also a discussion thread about the measurements - but also only in German.

Hier ist the Google Translate Link: https://www-open--end--music-com.translate.goog/forum/privatforen/thomas-michael-rudolph-tmr/651298-diskussion-ueber-messungen-an-ethernet-infrastruktur?_x_tr_sl=de&_x_tr_tl=en&_x_tr_hl=de&_x_tr_pto=wapp

 

And just to make it more clear: I am Eric (also in the German Forum) - Tom is my nickname. The Forum is a privat forum of Thomas, who kindly provided a read only thread for my measurements (this is the reason why the posts were done by Thomas).

[jabbr]

On 7/28/2022 at 5:45 AM, TomJ said:

This is also what Intel does and states in its test manuael for PHYs.

But perhaps the audiophile community here has developed a rocket science that was previously hidden from Intel.

But I only care about 100base TX. 

 

Ah - clock phase noise Measurements etc. This is all Irrelevant, because what counts is what comes out of the boxes and reaches the recipient. And that is the differential signal and common mode. There is nothing else, if we assume that there is no GND connection via a screen.

 

Oh ok because 100base-Tx is 100Mhz and yes a 1Ghz scope is ok for that ...  that specification is circa 1995 and 1Ghz scopes were considered fast in those days. Does Intel still make 100base-X NICs?

 

So no nothing is hidden from Intel and in this century Intel is concerted with silicon photonics eg

https://www.intel.com/content/www/us/en/architecture-and-technology/silicon-photonics/silicon-photonics-overview.html

https://newsroom.intel.com/news/intel-demonstrates-industry-first-co-packaged-optics-ethernet-switch/

 

As you can see Intel's current lineup includes 100-400 Gbe

 

This isn't "audiphile community rocket science" rather mainstream networking rocket science.

 

Now ... all this said your measurements seem to support the idea that common mode noise transmission is the primary factor affecting Ethernet "SQ" which is what my much more limited testing first pushed me to use fiberoptic ethernet. I am surprised the common mode noise values are as high as they are (100-200 mV) despite the Ethernet PHYs and I can imagine they might be even higher in some circumstances. Those values are indeed measurable!!!

[Jud]

26 minutes ago, jabbr said:

 

Now ... all this said your measurements seem to support the idea that common mode noise transmission is the primary factor affecting Ethernet "SQ" which is what my much more limited testing first pushed me to use fiberoptic ethernet. I am surprised the common mode noise values are as high as they are (100-200 mV) despite the Ethernet PHYs and I can imagine they might be even higher in some circumstances. Those values are indeed measurable!!!

Should be noted (assuming I’m understanding correctly) that the EtherRegen common mode noise measurements (done with copper input and output, not optical) are apparently the best of the limited number of switches measured.

[TomJ]

22 minutes ago, jabbr said:

 

Oh ok because 100base-Tx is 100Mhz and yes a 1Ghz scope is ok for that ...  that specification is circa 1995 and 1Ghz scopes were considered fast in those days. Does Intel still make 100base-X NICs?

 

So no nothing is hidden from Intel and in this century Intel is concerted with silicon photonics eg

https://www.intel.com/content/www/us/en/architecture-and-technology/silicon-photonics/silicon-photonics-overview.html

https://newsroom.intel.com/news/intel-demonstrates-industry-first-co-packaged-optics-ethernet-switch/

 

As you can see Intel's current lineup includes 100-400 Gbe

 

This isn't "audiphile community rocket science" rather mainstream networking rocket science.

 

Now ... all this said your measurements seem to support the idea that common mode noise transmission is the primary factor affecting Ethernet "SQ" which is what my much more limited testing first pushed me to use fiberoptic ethernet. I am surprised the common mode noise values are as high as they are (100-200 mV) despite the Ethernet PHYs and I can imagine they might be even higher in some circumstances. Those values are indeed measurable!!!

 

Dont want to go into this discussion, because i have done this too much, but 100base TX works with Multi Level Transmission MLT-3 so the bandwidth isnt 100MHz . . . . can google about this and we should not spam this thread with this well known stuff.

[TomJ]

11 minutes ago, Jud said:

Should be noted (assuming I’m understanding correctly) that the EtherRegen common mode noise measurements (done with copper input and output, not optical) are apparently the best of the limited number of switches measured.

Yes - but only on ports at side "A".

And that an external 10MHz clock increases common mode noise, just as it increases Ethernet jitter.

[jabbr]

4 minutes ago, TomJ said:

 

Dont want to go into this discussion, because i have done this too much, but 100base TX works with Multi Level Transmission MLT-3 so the bandwidth isnt 100MHz . . . . can google about this and we should not spam this thread with this well known stuff.

 

Yeah, typo, I meant 100MbE or 100 megabits per second Ethernet, not 100Mhz. Regardless a 1Ghz scope is not adequate to make jitter measurements on 1 GbE which is the common speed used on home ethernet. Intel doesn't currently use 1 Ghz scopes to test Ethernet regardless of what they wrote in the previous century.

[Jud]

7 minutes ago, TomJ said:

Yes - but only on ports at side "A".

And that an external 10MHz clock increases common mode noise, just as it increases Ethernet jitter.

Yes, the side A ports measuring better than side B was a bit of a surprise. An external clock increasing jitter is not surprising technically.

[TomJ]

12 minutes ago, jabbr said:

 

Yeah, typo, I meant 100MbE or 100 megabits per second Ethernet, not 100Mhz. Regardless a 1Ghz scope is not adequate to make jitter measurements on 1 GbE which is the common speed used on home ethernet. Intel doesn't currently use 1 Ghz scopes to test Ethernet regardless of what they wrote in the previous century.

You are wrong - read the linked Intel paper in my thread and you will see that they used the same oscilloscope and the same probes as I for 1000base TX. Its not the newest paper, but they have done this.

[jabbr]

23 minutes ago, TomJ said:

You are wrong - read the linked Intel paper in my thread and you will see that they used the same oscilloscope and the same probes as I for 1000base TX. Its not the newest paper, but they have done this.

I'm sure you know that the testing standard was entirely revamped between 1Gbe and 10 GbE (10Gbase-X) in which the stressed receiver jitter testing was introduced. Sure you can do basic compliance testing for 1 GbE but that doesn't mean that you can do accurate jitter measurements ... its not just the speed of the scope

[TomJ]

I do it with 100base tx, as also Etherregen only supports on side B 100base tx and its enough for most of us.

And therefore the scope is capable to measure jitter and was used by network specialist in the past.

And common mode noise will not much differ between the bandwidths - but you will know all this, because you are for sure an expert of ethernet jitter and common noise measurments . . . 

Its the first measurement of its kind in the audio domain, where now we can talk about the findings and i don't want to discuses with people which are not interested in this about 10GbE stuff.

 

 

[jabbr]

23 hours ago, TomJ said:

And common mode noise will not much differ between the bandwidths - but you will know all this, because you are for sure an expert of ethernet jitter and common noise measurments . . . 

 

Your measurements of common mode noise seem rather high at 180mV and even at 90mV for the EtherREGEN port. The noise/jitter allocations for each step in the chain go down as network bandwidth goes up e.g. at 100Gbe its even stricter. I doubt those levels of noise would pass compliance.

[TomJ]

6 minutes ago, jabbr said:

 

Your measurements of common mode noise seem rather high at 180mV and even at 90mV for the EtherREGEN port. The noise/jitter allocations for each step in the chain go down as network bandwidth goes up e.g. at 100Gbe its even stricter. I doubt those levels of noise would pass compliance.

As I wrote in the posts of my measurement Thread: The measurements are only valid for comparisons. Not absolut regarding the values.

[The Computer Audiophile]

34 minutes ago, TomJ said:

As I wrote in the posts of my measurement Thread: The measurements are only valid for comparisons. Not absolut regarding the values.

I certainly hear you, but if the measurements aren’t 100% valid, how can a comparison be valid? Something seems off. 

[jabbr]

26 minutes ago, TomJ said:

As I wrote in the posts of my measurement Thread: The measurements are only valid for comparisons. Not absolut regarding the values.

I hear you. EMC/RF shielding to do proper common mode noise testing can be difficult -- need faraday cage/lab. I have said many many times that my opinion about the reason for different "SQ" of different copper Ethernet devices is likely due to common mode noise and not even "jitter". The point about 10Gbe isn't that this speed is necessary, rather that starting with this standard. compliance testing ensures that jitter and noise are not passed across network hops and do not accumulate. The point about fiber isn't that the bits going to the DAC are better because they aren't, rather that fiber doesn't transmit common mode noise.

[TomJ]

On 7/31/2022 at 8:56 PM, The Computer Audiophile said:

I certainly hear you, but if the measurements aren’t 100% valid, how can a comparison be valid? Something seems off. 

I meant, like all measurement also mine are influenced by environment - I do not have an EMC lab with a shielded room.

Thus, the measurements in other environments may have a difference, but the measurements made in the same environment (like mine) are valid in relation to each other.

 

And since there have been no measurements anywhere, these are the best that are currently available - or can anyone tell me measurements regarding jitter and common mode noise of AUdiophile switches?

 

I have had the discussions about the validity of the measurements a thousand times - unfortunately mostly with people who were looking for reasons to doubt them and not with people who had a clue.

 

[TomJ]

On 7/31/2022 at 9:17 PM, jabbr said:

I hear you. EMC/RF shielding to do proper common mode noise testing can be difficult -- need faraday cage/lab. I have said many many times that my opinion about the reason for different "SQ" of different copper Ethernet devices is likely due to common mode noise and not even "jitter". The point about 10Gbe isn't that this speed is necessary, rather that starting with this standard. compliance testing ensures that jitter and noise are not passed across network hops and do not accumulate. The point about fiber isn't that the bits going to the DAC are better because they aren't, rather that fiber doesn't transmit common mode noise.

As described above, although I do not have a shielded measurement room, the measurements are comparable.

But your thesis regarding CM-noise agrees with my findings.
If I understand you correctly, you say that at 10Gbe the requirements for compliance with CM-noise are higher and thus it is ensured that network devices produce less of it - right?

 

With fiber, I have the following concerns regarding the argumentation: 
If a switch is well designed in terms of Bob Smith termination and additionally grounded, very little of the noise upstream of the switch will reach the network downstream.

I have not yet tested a fiber-copper converter, but there are statements from developers that the fiber components are strong noise producers.

[jabbr]

On 8/4/2022 at 3:39 AM, TomJ said:

As described above, although I do not have a shielded measurement room, the measurements are comparable.

But your thesis regarding CM-noise agrees with my findings.
If I understand you correctly, you say that at 10Gbe the requirements for compliance with CM-noise are higher and thus it is ensured that network devices produce less of it - right?

 

With fiber, I have the following concerns regarding the argumentation: 
If a switch is well designed in terms of Bob Smith termination and additionally grounded, very little of the noise upstream of the switch will reach the network downstream.

I have not yet tested a fiber-copper converter, but there are statements from developers that the fiber components are strong noise producers.

 

I am saying that fiberoptic networks do not transmit common mode noise through the glass ethernet cable. I've done no comparison testing of 10 Gbe copper, nor recommend it due to the higher power needs.

 

10Gbe compliance testing ensures that upstream noise, is not retransmitted downstream, whether that be common, differential noise nor phase noise. More precisely this is defined in the "stressed receiver" testing. 10 Gbe and newer uses end to end testing.

[TomJ]

18 minutes ago, jabbr said:

I am saying that fiberoptic networks do not transmit common mode noise through the glass ethernet cable. I've done no comparison testing of 10 Gbe copper, nor recommend it due to the higher power needs.

Here is what I said:
There haven't been measurements of fiberoptic converters so fare. So I can't say with 100% certainty that a network galvanically isolated by fiberoptics will have less noise at the endpoint - that's all I wanted to say.

The biggest problem is the switch itself as a noise producer, less the upstream in my opinion.

Will look at the 10GBe stuff. But if BS is implemented proper for each port, then in my measurements there is nothing I can see critical from upstream noise in downstream.

 

[jabbr]

38 minutes ago, TomJ said:

Here is what I said:
There haven't been measurements of fiberoptic converters so fare. So I can't say with 100% certainty that a network galvanically isolated by fiberoptics will have less noise at the endpoint - that's all I wanted to say.

The biggest problem is the switch itself as a noise producer, less the upstream in my opinion.

Will look at the 10GBe stuff. But if BS is implemented proper for each port, then in my measurements there is nothing I can see critical from upstream noise in downstream.

 

You were specifically discussing common mode noise transmission over an ethernet cable from different ports on a switch.

 

common mode noise simply is not transmitted over a fiberoptic cable. The fiber could transmit intensity noise and jitter. Both intensity noise and jitter would be seen on things like an eye pattern. The 10GbE+ specs do specify eye patterns.

 

Common mode noise at a fiberoptic endpoint would arise from the endpoint itself, not a port on a switch (the switch could emit noise over the power lines that could couple to the endpoint power supply -- i do use a robust isolation transformer in my audio area to prevent coupling with other electrical devices such as refrigerators etc)

 

The newer ethernet specifications e.g 10Gb and newer require **noise rejection** such that noise may not accumulate across hops -- otherwise the network simply wouldnt work and the internet infrastructure is 100Gb and up these days...

[jabbr]

From my POV I'm more concerned with the amount of noise at the endpoint than the switch (because I use 10+Gbe fiber switches) so compare the noise in the Intel x520 vs Mellanox vs OpticalRendu vs ClearFog ***

 

Its the endpoint that is electrically connected to the DAC ... typically via USB

 

*** I have no affiliation with ClearFog, just that circa 2017 it was the available low powered endpoint with an SFP port

[Jud]

31 minutes ago, jabbr said:

 

From my POV I'm more concerned with the amount of noise at the endpoint than the switch

 

Sound reasoning all around (with 10GbE optical common mode noise doesn’t accumulate across hops, so all we have to be concerned about is the endpoint), but people thinking about this should still concern themselves with noise that components and power supplies are throwing onto the power side of the circuit. (I know you’re careful with power supplies and have an iso transformer, but wanted to mention this for the benefit of others.)

 

In that light, @TomJ isn’t wrong to be interested in the noise a fiber to copper converter inside a switch may be putting out. It wouldn’t be a bad thing to do some measuring, and also not a bad thing to put out information about various best practices for keeping electrical noise generated by network components from affecting the eventual output.

[TomJ]

1 hour ago, jabbr said:

From my POV I'm more concerned with the amount of noise at the endpoint than the switch (because I use 10+Gbe fiber switches) so compare the noise in the Intel x520 vs Mellanox vs OpticalRendu vs ClearFog ***

At the end of the day it is important what noise will be carried through USB to the DAC. Is there any information if clearfog has put effort here?