Do I have a Network Bottle neck

GiddyFish

Active Member
Hi I'm trying to figure out if I have a bottle neck or if what I'm experiencing is as good as it gets without spending hundreds of pounds upgrading

My understand is in theory with gigabit you can reach transfer speeds up to 125 MB/s

Transferring a 20 GB file from my PC to my Synolgy NAS took 35 minutes using windows explorer reportedly at around 11 MB/s
CopySpeed.JPG

Even taking into account HDD read / Wright speeds that suggest fast Ethernet not gigabit ?

My main PC has 1 gigabit port built into the mobo this is connected directly to BT Home Hub 6 (Which has 4 gigabit ports)
the Ethernet status report this to be 1.0 Gbps
EithernetStatus.JPG

Again my understanding is BT Home Hub 6 is a modem & router it connects to the internet and assigns internal IP addresses to all attached devises both static, fixed, wired and over WH-Fi. It also acts as a switch.
This is connected to a Netgear 8 port GS08 gigabit network switch my Synolgy NAS (4 gigabit ports) is connected to this via two cat5e cables
See diagram bellow

The Netgear switch handles internal data transfer?

So the file going from the PC is going through both the router and the switch to get to the NAS?

I thought about adding a £10 pci-e card to the PC and having this connect to the switch not sure if this will by pass the router?

I'm hopping someone can clarify my understanding and if I do have a bottle neck suggest what I can do
Thanx

Network.png
 

gvh

Active Member
Looks fine to me.
Just be careful with your units! This might help

I'm wondering if the NAS is limited to 100 not 1000. Some switches and network cards show different colour lights depending on the speed. What model is it? (I've never owned a Nas btw)
 

gvh

Active Member
Did you say 2 cables into the nas from the switch? Remove one and see what happens

At this point I suggest you plug both machines into the bt switch and eliminate the netgear. I also appreciate that is likely to be hard.

When copying a file look at task manager, performance tab, select the network. It might help.
I wouldn't recommend a second network card in your pc. You are asking for confusion!
 

cjed

Well-known Member
As gvh says, you should only have a single ethernet cable from your Netgear switch to the NAS, you should remove one. I'm assuming your switch as a GS608 (you have it labelled as G8S608 on your diagram), in that case the port number lights on the front will be green for a 1Gbit connection and orange for a 100Mbit connection. Both the connections to your BT Home Hub, and to the NAS from the switch should light up as green.

The multiple ethernet ports on the DS1520+ are for a technique called Link Aggregation, this is only available when connected to specific managed switches. Your Netgear switch isn't a managed switch so should only have a single connection to your NAS.
 

mickevh

Distinguished Member
My understand is in theory with gigabit you can reach transfer speeds up to 125 MB/s

"Throughput" on Gigabit ethernet will never go that fast. Data networking equipment specifies it's "speed" in something called the "link rate" (sometimes called "datalink rate" or "layer 2 rate,") which is a different "thing" from Throughput (what you observe using speedtest, copying a files, etc.) Ethernet has a pretty high "protocol efficiency" at about 97% (in ideal conditions) so the high 110MB/s (note "bytes" not "bits") is what you typically see for gigabit ethernet Throughput in ideal conditions.

11.1 MB/s throughput is just screaming that you have a 100mbps link somewhere in the pathway between source and sink.

Don't waste time using Internet "speed tests" trying to diagnose local performance issues - the speed of your Internet service is irrelevant in this instance as it's not involved in the transfer. You could even unplug your Internet line (domestic harmony permitting) and I'll bet it makes no difference to your symptoms (except your ookla speedtest will fail.)

As others have observed, when using ethernet technologies, you must not use multiple physical links between devices unless both devices are capable of something called Link Aggregation or both your NAS NIC's have been given different (independent) IP addresses. Or maybe there's some proprietary NIC "teaming" technology on your NAS that can work without an LA capable switch, but it's ages since I've seen such as everyone uses LA since LA got codified as an IEEE standard (IEEE is the body that defines a bunch of networking standards.) Maybe your NAS (or switch) is doing something to "cope" with your twin NAS links and perhaps that's pulled it down to 100mbps.

I concur with the others, pull out one of the links fro your NAS. If that makes no difference, then it's a case of setting up the minimum pathway between source and sink (say PC---switch--NAS) then progressively introducing the other components back into the pathway until you find what' causing the problem. Maybe you have a bum cable lobe that's only working at 100mbps.
 
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GiddyFish

Active Member
Morning

I plugged 1 cat 5e cable from the NAS directly into the router and transferred a File between PC and NAS (using the same cable)
I instantly got around 54 MB/s
NewSpeed.JPG

This either means the cable from the router to the switch is faulty or the switch

Second test swooped cable for a new Cat 8 cable from router to NAS
2ndTest.JPG

That gave me two good cables OK the new one is better

Third reintroduced the switch into the loop using the two good cables

Back to 11MB/s
I conclude the switch is faulty during this test the lights didn't turn green


In regards to why I had two cables to the NAS my understanding was Synolgy could handle the Link Aggregation by creating a network bond and didn't need a managed switch

Synology NAS supports multi-LAN, allowing you to combine those LAN interfaces using the Link Aggregation technology. Link Aggregation increases the bandwidth of your Synology NAS by aggregating multiple network interfaces and provides traffic failover to maintain network connection in case the connection is down.

Link Aggregation


Edit:

Swapped the switch for a different 1 and re tested

NewSwitch.JPG

Thanx for your help
 
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tich77

Active Member
Your are correct in that the SYnology can create a 'bonded' lin using multiple ports. However, the switch that these connect to must also support bonding, and using the same protocol as the Synology.

This will require a managed switch. A cheap-as-chips Dell PowerConnect 2816 will happily handle two bonded interfaces.

BUT, this will not double your device-to-nas transfer rate from 1GB to 2GB (or 110mb to 220mb), Even with two bonded (or 'teamed') NICs in your device (PC), as the TCP connection is still as single stream.

What it does do is provide double the bandwidth from switch to NAS, so - provided the disk subsystem can handle the requests and transfer data fast enough - you can have, for example, two clients transferring data at 1GB each.
 

GiddyFish

Active Member
Your are correct in that the SYnology can create a 'bonded' lin using multiple ports. However, the switch that these connect to must also support bonding, and using the same protocol as the Synology.

This will require a managed switch. A cheap-as-chips Dell PowerConnect 2816 will happily handle two bonded interfaces.

BUT, this will not double your device-to-nas transfer rate from 1GB to 2GB (or 110mb to 220mb), Even with two bonded (or 'teamed') NICs in your device (PC), as the TCP connection is still as single stream.

What it does do is provide double the bandwidth from switch to NAS, so - provided the disk subsystem can handle the requests and transfer data fast enough - you can have, for example, two clients transferring data at 1GB each.

Thanx for the clarification
The only time where two clients are likely to need to be transferring data at 1GB each at the same time coping to the NAS from PC whist streaming 4K movie to the TV (Not sure that needs gigabit speeds)
If this was an issue it's an easy work around and wouldn't justify the cost of a managed switch

Best buy some chips instead :)
 

oneman

Well-known Member
Thanx for the clarification
The only time where two clients are likely to need to be transferring data at 1GB each at the same time coping to the NAS from PC whist streaming 4K movie to the TV (Not sure that needs gigabit speeds)
If this was an issue it's an easy work around and wouldn't justify the cost of a managed switch

Best buy some chips instead :)
100mb will stream a untouched 4k bluray which is about the highest bitrate you will commonly come across so 1gb isn't needed for streaming.

There is a way of utilising multiple network connections without link aggregation and that is to assign each NIC in the NAS its own IP address. Then when you connect from your devices you connect to a different IP address. BUT you would need to ensure the devices are plugged into the same switch as the NAS else you are going to hit a uplink bottleneck between the NAS switch and devices switch unless you have 10gb link between the 2 switches.
 

ChuckMountain

Distinguished Member
The CAT5 and CAT8 cables should perform exactly the same in your environment assuming they are both working. The link speed will be the same in both cases.

Also depending on the files you are copying can have a dramatic difference, for example, small file sizes will normally take longer to copy.

As others have said the link aggregation attempt and unsupported switch is what is causing the issue.

Some file copy programs will also make use of multiple TCP connections so can use link aggregation to increase apparent throughput but since your PC only has one connection and your trunk is only gigabit probably no real benefits of having two cables.
 

GiddyFish

Active Member
As others have said the link aggregation attempt and unsupported switch is what is causing the issue.
It might not have helped but the actual switch is faulty
I undid this bridge on the NAS
and as explained I tested with known good cables
first without out the using the switch and again with it

Without I got gigabit speed but only 100 mbps with it
 

ChuckMountain

Distinguished Member
It might not have helped but the actual switch is faulty
I undid this bridge on the NAS
and as explained I tested with known good cables
first without out the using the switch and again with it

Without I got gigabit speed but only 100 mbps with it


I conclude the switch is faulty during this test the lights didn't turn green

The lights only turn on when they sync and establish a correct link. Just because a switch doesn't light up doesn't mean it is faulty. It's pretty rare for a switch to fail, normally the power supplies go. Having two connections that aren't in some of bridge (also established on the switch) will cause issues.
 
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mickevh

Distinguished Member
If the problem can be identified to a particular switch port, you might care to take a close look inside to socket and see if it's gotten dirty or there's a bent contact. It's rare - but it happens.
 

tich77

Active Member
Thanx for the clarification
The only time where two clients are likely to need to be transferring data at 1GB each at the same time coping to the NAS from PC whist streaming 4K movie to the TV (Not sure that needs gigabit speeds)
If this was an issue it's an easy work around and wouldn't justify the cost of a managed switch

Maybe. But... there is another usage scenario, when you have multiple clients accessing the NAS. Whilst they may not "need" 1GB, its far quicker to have 2GB of bandwidth available, rather than 1GB.
The case may not be 2 device, it may be 3, 4, 5 etc. You can never have too much bandwidth.

Secondly, a teamed link will load-share (in theory). Client A will transfer over the first link, Client B over the second, Client C over the first. This works nicely to smooth out transfers.
And makes for a little resiliency when some hapless muppet damages a cable.....
 

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