Comparison of motherboard network chips
All the modern motherboards come with on-board networking. The big motherboard vendors marketing departments like to make a fuzz about their "superior" on-board networking. How much of a difference does it make? Here's a quick run-down.
Gigabit network adapters provide gigabit speeds[edit]
It's that simple. Yes, really. A gigabit link will give you gigabit speeds regardless of the network adapter unless there is some kind of bottleneck like USB 2.0 in the case of USB network adapters. On-board network chips are connected by PCI-Express which is capable of speeds that are way higher than gigabit. However, there are some differences between the adapters which used to matter a more than they do today.
The contenders[edit]
All the motherboards you may consider buying will have a network adapter from either Intel, Qualcomm or Realtek. The quality of their products happens to be the same as the alphabetical order of those 3 options. The performance can, in theory, also be ranked in their alphabetical order. In practice it does not matter.
So what's the difference between the common network products?
Intel[edit]
04:00.0 Ethernet controller: Intel Corporation I211 Gigabit Network Connection (rev 03):
- Region 0: Memory at fe200000 (32-bit, non-prefetchable) [size=128K]
- Region 2: I/O ports at e000 [size=32]
- Region 3: Memory at fe220000 (32-bit, non-prefetchable) [size=16K]
- Capabilities: [40] Power Management version 3
The Intel I211 is really common on motherboards manufactured 2016-2019. This is what you get if you buy a motherboard with gigabit Ethernet made by Intel.
This family of chips is powered by the igb kernel module. It is mature, stable and it has been in the kernel for ages.
Qualcomm[edit]
05:00.0 Ethernet controller: Qualcomm Atheros Killer E2500 Gigabit Ethernet Controller (rev 10):
- Region 0: Memory at fe100000 (64-bit, non-prefetchable) [size=256K]
- Region 2: I/O ports at d000 [size=128]
- Capabilities: [40] Power Management version 3
MSI and Gigabyte like to market "Killer Ethernet" as "feature" which will improve gaming performance. It doesn't. The Windows driver will do some basic QoS and send smaller packets first. You can do this kind of QoS with any network adapter and it doesn't make a measurable difference. What does, in theory, make a difference is the larger memory size on Qualcomm chips.
Qualcomm chips like the E2500 use the kernel's alx module. It works great.
Realtek[edit]
06:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 15):
- Region 2: Memory at fe204000 (64-bit, non-prefetchable) [size=4K]
- Region 4: Memory at fe200000 (64-bit, non-prefetchable) [size=16K]
- Capabilities: [40] Power Management version 3
Realtek is considered to be the cheap option and it is what is commonly used on cheaper motherboards. It is also commonly used on cheap $5 network adapters from Ebay and sites like that. A quick glance at the memory used for send and receive buffering reveals why they are so cheap: You get less, all you get is the bare minimum. A busy very old single-core CPU could easily drop packets due to the low amount of on-board memory.
Realtek adapters use r8169 module which has been included in the Linux kernel since forever. It is mature and well supported though there have been some issues with TCP Segmentation Offloading in some kernel versions (there is a workaround).
Conclusion[edit]
The Hewlett-Packard Company NC364T is a enterprise-grade quad gigabit network adapter from 2009 which can be bought for around $30 if you find a good deal in the used market. The HP NC364T was a $750 part when it was introduced. That's not cheap, that is a price-point where it better be high-quality technology. Take a look at how this adapter from 2009 compares to those above:
03:00.0 Ethernet controller: Intel Corporation 82571EB/82571GB Gigabit Ethernet Controller (Copper) (rev 06):
- Region 0: Memory at f7e20000 (32-bit, non-prefetchable) [size=128K]
- Region 1: Memory at f7d80000 (32-bit, non-prefetchable) [size=512K]
It is apparent that high-quality enterprise-grade adapters, even those that are 10 years old, have a lot more on-board memory for send and receive off-loading. More memory equates to fewer interrupts required to handle network traffic. This used to make a difference when the Pentium II was trendy. It really does not matter if you are considering buying a motherboard for a modern CPU. That being said, if all things are equal and you can pick a network adapter then the choice would be Intel, Qualcomm (Atheros / Killer Ethernet) and Realtek in that order. Realtek stands out as the objectively worse in terms of what you get for your money. If all things are not equal and one board has better audio and a Realtek network chip and the other has horrible audio and Intel networking then the board with the better audio would be the logical choice since that is something which actually makes a real-world difference.
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