Ethernet bonding to increase transfer speed

hknatm

macrumors member
Original poster
Dec 21, 2018
75
6
Hi all,

I have been reading about this topic and lota of people say different stuffa.

I have a nas in my home (Thecus N4800) it has 2ethernet ports and 1pcie 1x lane expansion.

Also have a mac pro with 2 ethernet ports.

Now i know that link aggregation offers you the enhanced bandwith but some say that it increases the transfer speed if you do it with a switch that capable.

Now i am having the transfer rate of 106mb/s read 98mb/s write via 1gbps bandwith. I just want to learn about it can be doneor not and then act in that knowledge.
 

Mikael H

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Sep 3, 2014
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Regular network link aggregation of 1 Gbps ethernet connections will allow for multiple streams of 1 Gbps each, provided the storage subsystem can handle those speeds.

In other words: A single-threaded file copy operation will only ever reach around 100 MB/s across an aggregated link, but if you have multiple clients working simultaneously against a server with n aggregated links, their collective throughput may reach n times the link speed provided a number of criteria are met.

Simpler is usually better, provided it’s compatible with your existing machines: Switching to 10GbE network interfaces will increase the available throughput speed, provided you can find 10GbE NICs compatible with your NAS and your Mac Pro, and provided the NAS and its storage are powerful enough to make use of much more than a 1Gbps link.
 
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hknatm

macrumors member
Original poster
Dec 21, 2018
75
6
You say this even if the mac’s ethernet ports and nas’ ethernet ports have different mac adresses right? Some people managed to do it in linux, i dont remember the post in some forum but they are saying that this can be manupulated.
 

mmomega

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Dec 30, 2009
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Easier way to think of it is:
Aggregated ethernet channels don't double the speed of ethernet.
So 4 - 1Gigabit Ethernet ports will not add up to 4 Gigabits of throughput.

It allows for 4 - 1 Gigabit lanes into a device. Think more of a 4 lane highway leading in to a city rather than a single lane road.
The speed limit does not increase but because there are four lanes it can now move more traffic than the single.
The 4 ethernet ports allow 4 - 1Gb single lanes so it allows for MULTIPLE incoming and outgoing transmissions, it won't increase speeds for a single device.




If you want more speed over ethernet you have to increase that "speed limit" or invest into 5-10Gigabit devices.
Even then you will be limited to your slowest piece in the entire network which a lot of the times is a spinning hard drive.

A spinning drive will only read and write at 1 Gigabit speed, so if you have a 10Gb connection and the device you are reading or writing to has a spinning hard drive, you will only ever get MAX of 1 Gb speeds.

So for a consistent increase in network speeds, for 10Gb, you will need a switch that handles 10GB, devices or clients with 10Gb network cards and then at minimum SSD's(5GbMax) to nVMe drives(30'ish Gb) or a large amount of RAID'd spinning drives in a device with 10Gb.




Also, multiple ethernet ports on a single computer is normally there to address one of two issues.

Failover. So in the case of one port or that lane of traffic dies, there is another one to continue transmitting.

The second is if that computer is a server of sorts that hosts data, it allows more simultaneous transmissions of data.


Even with ethernet link aggregation you MUST HAVE an ethernet switch that will also aggregate the two or more ports together to allow this to happen. If the switch will not aggregate, then the ports on the computer will not aggregate either.
 
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Mikael H

macrumors 6502a
Sep 3, 2014
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You say this even if the mac’s ethernet ports and nas’ ethernet ports have different mac adresses right? Some people managed to do it in linux, i dont remember the post in some forum but they are saying that this can be manupulated.
NICs will always have different MAC addresses, or you’ll get all sorts of issues (it’s how the network infrastructure knows where to route traffic).

As I said, a single network connection will always max out no more than a single network interface. There are ways to start multiple parallel transfers, which may or may not utilize all interfaces in an aggregate link, but unless copying files back and forth is what you mainly do, you’re unlikely to see a benefit in real-world client applications from an aggregated link.
 
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hknatm

macrumors member
Original poster
Dec 21, 2018
75
6
I see all of your points now. This knowledge is sth that i close to. But i wanted to hear from you guys :)

Now i am searching my nas’s compatibility about 10 gbe lan pcie cards. It is a linux server i think i may have trouble about drivers right?

Nas : Thecus N4800
 

Mikael H

macrumors 6502a
Sep 3, 2014
657
285
I see all of your points now. This knowledge is sth that i close to. But i wanted to hear from you guys :)

Now i am searching my nas’s compatibility about 10 gbe lan pcie cards. It is a linux server i think i may have trouble about drivers right?

Nas : Thecus N4800
The issue with drivers for third-party NICs in your NAS isn’t that it runs Linux, but that it runs Thecus’ specific distribution. This likely introduces severe limitations compared to a more generic distribution.

But your first issue is that the poor N4800 NAS is an ancient design powered by an Atom CPU. It will likely struggle to deliver significantly higher bandwidth than its existing 1GbE connection can handle - you even said in an earlier post that it’s far from saturating a single GbE link when reading data (98 MiB/s = 0.82 Gbps).
 
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