I was also caught out and would like to voice my displeasure at this issue.
The particular Realtek IC is the RTL8106E and is apart of of PCIE family.
Its not like they did not have a fast enough bus internally to connect the NIC to.
They could of chose a better option such as the RTL8111CP which is a PCIE single chip solution and not cripple a laptop which has DDR4 and 7th gen i series processors.
Any laptop which has a 17.2 inch FHD and 7th gen Intel processors should automatically qualify for a Gigabit Ethernet port in 2017.
As a Systems administrator I take into account this philosophy:
I need to transfer 3-4 gigabit files multiple times a day. Without GigE I imagine how many hours over the lifetime of the laptop I would never get back being idle and waiting for a trivial file transfer
and without any suitable option to connect an external NIC to. No USB3 wont cut the dice nor would I want to carry an external adapter anyhow.
At the time of writing there is no other 17.3 inch screen solutions from dell so I have reverted back to my old Studio 1737 which has Gigabit Ethernet.
Even the specifications for the Dell M7710 at time of writing which costs AUD $8,985.90 only lists under networking a "RJ45" not the speed. Does this even have gigabit Ethernet?
A note to Dell: We need GIGABIT ETHERNET, SERIOUSLY.
I recently purchased a Dell Inspiron 24 3464 all-in-one desktop with Intel 7th gen processor. Although the computer is in the same room as the router and is getting 160-170 gbps speed on the wireless, I plugged the ethernet into my cable modem when I was doing some speed testing, using a cat 5E cable. I was shocked when my speed was only around 90 gbps. All other devices tested on the modem were around 215 gbps (we are paying for 200 with Suddenlink). Two of those devices tested were old Dells, one a five year old all-in-one and the other an eight+ year old laptop. Imagine my shock and anger when I discovered that the brand new desktop has a 10/100 ethernet card while the two older Dells have gigabit cards. I do not understand why Dell is doing this! There are some of us who do still need to use Ethernet, especially if a computer is too far away from the modem to receive a strong wireless signal.
These are designed to sell for as low a price as possible - it's cheaper to integrate a 10/100 chip than a gigabit chip, if only slightly - but that slight difference is reflected in the system's rock-bottom price.
Price pressures on low-end systems are enormous -- if an ODM (or the seller) can economize even for pennies a unit where most users will never notice, they will.
ejn63 is certainly correct on the economic realities of low-end PCs. In the era of smartphones and tablets, more and more people are willing to spend less and less on a PC, or even forego a PC entirely. That trend has resulted in PCs being available for historically low prices (adjusting for inflation), but that in turn leads to cost-cutting measures because the profit margins on such products are razor thin. And even offering the OPTION of a Gigabit adapter would increase the overall cost of the system due to the need for multiple component variants and the increased design, testing, and manufacturing flexibility required to deliver and support that.
But if you're sitting there saying, "I would have gladly paid a few extra bucks for Gigabit Ethernet!!!", then I would recommend spending those few extra bucks on a USB 3.0 to Gigabit Ethernet adapter. They cost $15-30, and on a desktop/all-in-one system, it wouldn't even be meaningfully less convenient since you can just keep it permanently attached and hidden behind the PC. StarTech even makes some adapters that include 1-3 USB 3.0 female ports built into them so that you can maintain or even increase the total number of USB 3.0 ports available on your system while you have the adapter connected.
Imagine my shock and anger when I discovered that the brand new desktop has a 10/100 ethernet card while the two older Dells have gigabit cards.
I have never known Dell to put 10/100/1000 Ethernet cards in their consumer-grade PCs which the Inspiron is.
Dell's business grade PCs have the Gigabit Ethernet port. Heck, my Latitude D620 from 2006 has a Gigabit Ethernet.