WARNING: Support staff ignored pre-approved RMA to swap KNOWN-DEFECTIVE product line for a different product and sent me back the same broken product

DO NOT BUY the ‘CM4 Router Board’ SKU 103110042 as it uses a known-defective RTL8111E chipset that CAN NOT even come close to reaching its advertised gigabit speeds. I was seeing MAXIMUM 80mbit/s unless I blew on the chip as it thermal throttled itself like mad.
80 megaBITS/SECOND unless I physically blew on it and even then only a few tens of mb/s.

The other router boards that use the RTL8111H do not have this problem.

I reported this and posted Seeed support a video demonstrating the problem and they OK’d an RMA so I could SWAP IT for an RTL8111H router board model.

But for some reason they replaced it with the exact same part! And now they tell me they won’t refund it either so I have USELESS defective router board I CAN NOT USE and have to go through the chargeback process to get my money back.


I gave it a high rating in the store before I performance tested the second gigabit port and I wish I could remove the endorsement.



Original request on the support ticket:

“Regardless of this being a faulty design or a single faulty unit, I
think I want to use a different router board. Can you refund this
order? Store credit is OK.
The more I Read about the RTL8111E variant (as opposed to the RTL8111H
variant), the more it sounds like this chipset is a dumpster fire with
terrible performance and instability.
“Please refund for store credit and I’ll send my unit back to you.”
“Happy to send m.i.n.e. to you first for assessment before you issue any
refund. I think that would be more useful than you testing a
different unit”

To which Seeed AGREED:

You’re right. Please fill out a ticket here and I’ll arrange it for you”

(nb: I had to type that word as ‘m.i.n.e.’ because that word without the periods between letters is blocked on the forum)

Frankly selling this as having dual gigabit ports is just outright lying and false advertising. It’s fraud. And the fact that you’re not stocking it anymore Seeed tells me you know this as well - so why the hell did you send your last piece of junk back to me instead of letting me buy a different product?

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It seems I am no longer able to edit or remove this post, but I’d like to say that I may be being too harsh on Seeed, and have just experienced an unfortunate series of misunderstandings, compounding the frustration. So I apologise to Seeed and appreciate their support staff continuing to work with me on this issue.

The comments about the product stand, however. Don’t buy it.
I’ve just discovered that during the course of my RMA process, Pi52 have themselves tested one of these boards, albeit insufficiently - only testing RX not TX of the RTL8111E in a second test, after failing to correctly isolate it in the first test. Still, their testing in their controlled environment and only testing 1 direction of bandwidth, still showed a greater than 10% drop of performance after a few seconds of sustained throughput. They concluded there was no design flaw with this. It’s still false advertising, and it’s still a piece of junk chipset that is unfit for purpose. If you’re lucky you’ll get their experience where it maxes out at 800mbit/s. Worst, you’ll get my experience where it maxes out at 80mbit/s unless you hardwire a fan to it, at which point you’ll get 400mbit/s if you’re lucky. Even Jeff Geerling noticed substandard performance during his testing, from memory around 400mbit/s to 600mbit/s. There seems to be a massive variance. It’s a game of roulette. Do not buy.