# Difference between cheap and expensive ethernet card (Open)

## ZaPa

Hello.

I have some questions about ethernet cards for a router linux.

There are many ethernet card of low cost, with chipset realtek for example, which price is 15$ - 20$... but i have seen others cards whish price is higher about 50$ with chipset intel..

My question is... Which is the difference between those ethernet cards? Because the cheaper cards offers until 1Gbps of speed...

My gentoo router offers service for more than 500 users.

I have the same question for the switchs nonadministrable. There are switchs nonadministrable until 1Gbps of speed for 20$ and others more expensive.

What is the real difference between one and others?

What card ethernet or switch i should buy?? There are some problem with low cost card for this number of users in my network? 

Maybe the cheaper ethernet could cause interrupts storm in my linux router?

Thanks.

*Sorry for my english

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## Ant P.

The main difference between a cheap realtek and a medium price intel is that the latter will probably support more of the hardware offload features as shown by ethtool; they may even be enabled by default. In some cases the hardware may support offloading for traffic control drivers too. Not all of this may be relevant to what you're trying to do though.

Also just because something is more expensive doesn't mean it's always better; the quality of Intel's drivers has been in sharp decline the past few years (across all hardware, not just the network cards). That $xx difference may be better spent on the CPU, moreso if you're going to be running a firewall on the router.

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## Ralphred

 *ZaPa wrote:*   

> I have the same question for the switchs nonadministrable. There are switchs nonadministrable until 1Gbps of speed for 20$ and others more expensive.

 

You need to be really careful with this, look at your network topology, some parts of it will be carrying more users data than others, and it's the high use areas you want to spend more money.

I've never had much long term success with un-managed switches at all, even the cisco budget ones. Now, I appreciate that the networks I typically design have very high bandwidth usage 24/7 and wouldn't suggest anyone builds to the same standards without having the same requirement. My sales department are always trying to push costs down and I've been forced to use a lot of cheap rubbish on budget networks over the years, that said I've never had issues with Netgear managed switches (I have had the unmanaged break after about 3 years) and they would be the cheapest item I'm likely to recommend to anyone.

Most importantly, at the lower end of the market, is to check the total throughput, I've seen throughput so low on some stuff only ~30% of the ports can be at 100% usage at any one time, be aware of this and keep this cheap stuff out of parts of your network that need the high throughput. Don't be afraid to use cheaper 100meg gear where there is no need for it to be faster too.

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## P.Kosunen

 *ZaPa wrote:*   

> My question is... Which is the difference between those ethernet cards? Because the cheaper cards offers until 1Gbps of speed...

 

Intel cards have always been hassle free in every operating system i have used. Those should be available from 20-30$ class (or even ~10$ from Ebay).

Realtek might need compiling proprietary drivers in some cases for stable operation.

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## szatox

 *Quote:*   

> . In some cases the hardware may support offloading for traffic control drivers too.

 Yeah, more expensive NIC may come equipped with TCP offload engine. Rumour says TOE is not supported in linux "because kernel should know about those connections".

Never tried it myself, I just know such hardware exists (and the vendors charge extra), and that you should double check compatibility before trying to save some CPU cycles this 

Also, you know, it's not uncommon for people to pay extra for their favourite brand's label.

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## Cyker

I'm currently running 3 NICs in my server; an old PCI 3Com 3c905b, an on-board Realtek 8168-something and a 4x PCIe HP card that is really a rebadged Intel 4-port 82571EB.

Out of the 3, the Realtek has been the worst; It drops packets under load and will randomly stop working, forcing a reboot to bring it back. I'm told it is better in newer kernel version, or if I use Realtek's own drivers, but I couldn't be assed to wait for that at the time so it's just unused now.

The 3Com I've had through 8 or 9 different computers and has been rock solid - 3Com made some damned good gear back then. I am desperately hoping someone brings out a Ryzen mATX board with PCI on it so I can keep it when/if I upgrade. (Also ECC and 8x SATAs please! ^____^)

The HP/Intel is a server-grade board I got dead cheap off eBay; 2 of the ports don't work, but the remaining 2 have been doing the bulk of the work; Even being maxed continuously for multiple days they haven't missed a beat.

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## eccerr0r

I have many on-board rtl8169's that I never had problems with - except when the cable goes bad.  Because of all the badmouthing I've read I assumed a bad rtl8169 but when I swapped it with an Intel PCI ethernet that STILL didn't work, I finally found it was a bad ethernet cable.  So, it wasn't the rtl8169 after all.  

The rtl8169 hasn't been much of a problem, been passing near linefill (1Gb/sec) without packet losses to my intel and marvell gbit ethernet chips.

The only rtl8169 I really had problems with is one that's on a PCI card whose regulator failed...  Other than that, the only rtl8169's that end up maxing out at 40MB/sec are the PCI 32/33 boards that are bottlenecked by PCI.  I don't know if I have any other true Gbit cards that are not rtl8169 for PCI 32/33, so it seems like the people making these boards are giving RTL8169s a bad rap.

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## chithanh

The saying goes that Realtek network chips are a buggy mess which are barely held together by drivers.

For example, the r81xx do not work properly in the presence of an IOMMU, and quirks or workarounds need to be applied to make them not suddenly stop talking on the interface.

Some further reading:

Gigabyte 990FXA-UD3 Installation misery

ethernet module crashes with IOMMU enabled

https://bugzilla.kernel.org/show_bug.cgi?id=14962

https://bugzilla.kernel.org/show_bug.cgi?id=55841

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## eccerr0r

 *chithanh wrote:*   

> The saying goes that Realtek network chips are a buggy mess which are barely held together by drivers.

 

Same could be said for a lot of chips, not necessarily network chips... code hacks are everywhere :-(

<cough>KPTI</cough>

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## P.Kosunen

 *Cyker wrote:*   

> The 3Com I've had through 8 or 9 different computers and has been rock solid - 3Com made some damned good gear back then.

 

I remember those old ~one inch wide Paraller Tasking chip 3Com 90x's were rock solid, but newer ones with smaller ~1cm chip had many bad ones.

old

new

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## Cyker

Yeah, it's one of them - Full-sized with an actual ROM socket, none of this half-height pansyness!  :Razz:  It even has 10base2 coaxial and AUI!!

Ahh 3Com, how far you fell....

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## eccerr0r

IIRC the last common 3com card with AUI and/or BNC was ISA - 3c509 which was an excellent card no less.  I don't think the 59x or 905 series (PCI) had BNC though may have AUI...

Lets not forget the 3c501 where Linuxers learned where the word "borken" came from...

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## ZaPa

WOW! Thanks to everybody for all the answers. I'm impressed.

No one talk about this question in the network topic and is very important for implement a good network (is only my opinion). A lot of people buy expensive hardware for the networks for the unique reason is very expensive but I think they don't know which is the difference between cheap hardware o expensive hardware. For example I've seen expensive switchs in bussiness only for 3 or 4 computers and 2 inkjets...  The owner of the bussiness paid much money for this. 

I have a gentoo router with 3 ethernet cards with realtek chipset (but this computer is not server 100% it has desktop hardware), and I'm having a problem with the process ksoftirqd/3. I've been researching about this and I think this problem is caused by a realtek card which doesn't have MSI-X function and the 3º core of my cpu is with 90-95% of cpu when the load of my network is high. Also, thanks to your answers I have understood many things.

I have a question. This is my scenario:

Wan Connections --->        Gentoo Router     -----> Switch TPLINK nonadministrable  -----> My Lan

With this scenario, Which switch nonadministrable I should buy? In this part i don't need the switch be administrable.

At rush hour I have 250Mbps of download speed, but i don't know if my switch is inneficient to do that. There are much people connected to my network about 500/600 people which causes much simultaneos connection (i use connlimit and randomlimit to limit simultaneos connection)

I hope you can recommend something to me. 

Thank you very much for your answers.

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## P.Kosunen

Unmanaged switches generally don't decrease speed, even cheap ones can keep up full 1Gbps load between ports.

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## Cyker

 *eccerr0r wrote:*   

> IIRC the last common 3com card with AUI and/or BNC was ISA - 3c509 which was an excellent card no less.  I don't think the 59x or 905 series (PCI) had BNC though may have AUI...

 

Well I have one right here so I can shoot that down  :Razz: 

There are 3 variants of the 3c905 I know of; the plain 905, the 905b combo, and the 905c - The 905c is probably the most prolific, and I've only seen TP versions of the 905 and 905c, but the 905b was a full height card which had all 3 interfaces! We had loads of 905b's from when we were transitioning from coax to twisted pair, and esp vs the D-Links we were also using, they were by far the fastest cards, having precursors to what would grow into TOE on modern cards, and that made a big difference on the slow 486 and Pentiums of the day!

Ironically and WRT the OP's thread, I'm told TOE is now pointless as modern CPUs are so ridiculously fast it's quicker to do it all in software!

It is utterly insane when you think about how much processing power we have available to us now, yet I swear a lot of the time computers don't *do* things any faster than those old 486s! (*he says while waiting for his Windows 10 work computer to restart after updating*)

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## Tony0945

 *Cyker wrote:*   

>  I am desperately hoping someone brings out a Ryzen mATX board with PCI on it so I can keep it when/if I upgrade. (Also ECC and 8x SATAs please! ^____^)

 

I updated one desktop last week with an MSI B350 Tomahawk Arctic. I bought it specifically for the two PCI slots. I'm pretty happy after updating the BIOS (it was four revs behind and took forever to get to the Bios screen). However, it is full ATX and only four SATA ports. No ECC. Runs the r8169 driver fine right out of the box (kernel 4.14.13). It has a good rep for Ryzen although I'm running a Bristol Ridge.

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## eccerr0r

Ah... I figured there may have been one, just have rarely seen any PCI 10b2 cards out there.  AUI was the last bastion of hope.  Now, how about a 10b5 built-in transceiver card for a PC-compatible of any kind :D

And hopefully the PCI 8169 is a 64/66 or PCIe or on motherboard or something like that.  Every 32/33 PCI 8169 I've run across can't hit over 40MB/sec or so.  The 8169 relatives (8111?8411?8168?) embedded on motherboards (tend to be PCIe) run just fine.

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## Tony0945

 *eccerr0r wrote:*   

> Ah... I figured there may have been one, just have rarely seen any PCI 10b2 cards out there.  AUI was the last bastion of hope.  Now, how about a 10b5 built-in transceiver card for a PC-compatible of any kind 
> 
> And hopefully the PCI 8169 is a 64/66 or PCIe or on motherboard or something like that.  Every 32/33 PCI 8169 I've run across can't hit over 40MB/sec or so.  The 8169 relatives (8111?8411?8168?) embedded on motherboards (tend to be PCIe) run just fine.

 

It's embedded on the motherboard. I wanted the PCI for a HVR-1600 television card.

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