What is the throughput is required by two full-duplex gigabit ethernet connections

I would like to add a daul port nic to my system.
I've got an Gen. 2 pcie 1x slot and thought of buying the hp NC360T and adapting (dremel+cutting wheel) the 4x connector to 1x.
But I'm not certain if I would create a bottle neck.
The NC360T is Gen.1 4x card so it has a theoretical throughput of 1000MB/s. If I were to fit it to a Gen.2 1x slot it would have a max throughput of 250MB/s.
Now here my question how much throughput do 2 full duplex gigabit ethernet connections require? (1MByte=1MB=8Mb=8Mbit)
1) 2*1000Mbits=2000Mbits=250MB/s
or
2) 2*(1000Mbits up +1000Mbits down)=4000Mbit=500MB/s
I just want be be sure but I think I would create a bottleneck

Thanks for the help

Zitat von davidh2k

Could you please recheck that you use megabyte/ and megabit/s correctly? From just reading your post I'm not sure...

For full dual gbit throughput you would need 250megabyte/s (2000megabit/s) DUPLEX throughput.

Greetings
David

I did use 1Byte=8bit correctly.
So if I understand you correctly the max throughput of one full duplex gigabit ethernet port is 1000Mbit so concurrent 500Mbit up and down would be possible.

Zitat von raulfg3

you can expect only about 200MB/s in file transfer and only for several concurrent connections. aka: this mean that you can not notice increase on througput if you try to copy/move a single big data file.

PD: and you need a proper Switch to manage aggreated connections.

I don't want to increase my link speed from my pc to the server, but want run a pfsense in a vm and want to separate my connections.

Zitat von Enra

usually GigabitEthernet works in full-duplex mode.
Allthough half-duplex is defined in the specs I've never seen that in real life.
That means you have 1000MBit/s up and down concurrent.

For two two full-duplex gigabit ports that would result in:
2 *(1000Mbit/s "up" +1000Mbit/s "down)=4000Mbit/s=500MByte/s

That would mean that I would create a bottleneck when running the nic in pcie Gen.1 1x mode vs 4x mode

Zitat von urbansk

You will get 125 MB/s from one NIC

There seem to be different opinions out there.
I would appreciate it very much if I could get an answer by some one who is 100% certain of how much bandwidth on the pcie bus it requires to run two full-duplex gigabit Ethernet connections.
a) 2Gbit/s
or
b) 4Gbit/s

Zitat von Enra

It's not a matter of opinions.
Again:
Full duplex means transmitting and receiving at the same time.
Gigabit Ethernet means transmitting and receiving with 1 Gigabit/s.

Than take a look on the PCIe specs and the rest is simple calculating
Wheter your HDs are capable to read and write these datas is another calculation ....

I hear you, but

Zitat von Enra

Gigabit Ethernet means transmitting and receiving with 1 Gigabit/s.

is a bit vague when you not sure what it means.

If you would confirm or deny the correctness of the following statement I would very glad:
A single full-duplex gigabit ethernet connection requires a 2Gbit/s connection on the pcie bus to not be bottle necked.

Zitat von ryecoaaron

Did you google the pci-e standard?

Yes and I'm aware of the speeds regarding pcie. But I was not sure about the bandwidth requirement for full duplex gigabit connection.

Zitat von ryecoaaron

pci-e version 1 using 1x slot is 250 MB/s second. So, it can handle 1 gigabit full duplex port with upload and download saturated
pci-e version 2 using 1x slot is 500 MB/s second. So, it can handle 2 gigabit full duplex ports with upload and download saturated

Thank you very much!!
That answers my question

The problem is I only have a pci-e Gen.2 1x slot on my motherboard and nic I was looking at hp NC360T is only pci-e Gen.1 and has a 4x connector. If I were to make that 4x connector fit I would create a theoretical bottleneck.