Hey there!
I have urbackup-server (raspi 3B+) in the network. It is attached via switch (Netgear GS105v5) to the ipfire (duobox / tx-team) and the full backup runs between 15 and 120 Mbit/s. Is it normal?
As it seems, I have no bottle necks. Raspi, Switch and Duobox do all have 1GB-Lan. The Cables are cat5, one of them (client to ipfire) is very old and looks not so good, so maby this is the problem?.
Best regards
dieter
The RPi 3B shares network and USB on the same bus, so you canāt expect gigabit speeds.
In ideal use case you can expect theoretically around 224 Mbps (see https://www.jeffgeerling.com/blogs/jeff-geerling/getting-gigabit-networking), but the real world performance should be less (e.fg for random writes of small files)
I also use UrBackup with a number of clients (DietPi and Windows clients) and it is quite slow.
But this depends on network speed (like Jappe mentioned), disk speed (I used USB mounted HDDs) and the client speed itself.
For me, it works and I let run the backup like it wants to run. I donāt care for speed, because the backup does not slow down the rest of my system. So I did not invest more hours for optimizing it (which is generally bad for me as an engineer). 
Q: Is the slower speed only a minor flaw or does it also limits your work in some cases?
oh, thanks for the info!!
I thought, it must be somehow bottleneck.
Whats about Raspi 4?
And by the way, what about LIme2-Server from olimex? I think there is no possibility to get dietpi run on that machine?
I suppose it does not slow down other processes. But in my case, I want rather quick backup. As it seems back via my raspi 3 for about 800GB will last 1-2 days. Its definitely too long 
On the RPi 4 you can get full Gigabit Ethernet speed, it does not share the bus with the USB ports.
They provide a debian image for it, so you could try an run the installer script, but they only provide images with kinda old kernels (3.4)
https://www.olimex.com/wiki/A20-OLinuXino-LIME2#Linux_images
ah, so itās better to upgrade!
yeah, I tried them all and get no internet connection. Already asked in armbian und debian forum, but got no solution. So Lime2-Server seem to be something for very skilled geeks. Pity that, because its a nice peace of open hardware.
Are there some other good boards to install dietpi and use full 1GB of eth instead of raspberry? Maby pine64?
If you just did not get an answer, they have no full official support, but do provide images: Olimex Lime 2 ā Armbian
The āArmbian Bullseye Minimal CLIā one should be a nice starting point to use or convert into DietPi with our installer script. The Armbian images (i.e. their kernel/bootloader package composition) is well integrated into our installer since we use their package repository as well for many of our images.
I already tried it, but still could not activate eth0. I think itās a problem of Lime2-Server-Hardware.
More likely the kernel. That they do only offer Linux 3.4 Debian Jessie images says everything, i.e. no proper mainline kernel integration has been done, and hence the Armbian mainline-based kernel is likely to miss features.
do you have an idea, what can I install on the Lime2-Server to get a working network?
If Ethernet is not detected, a kernel drive or device tree entry is missing or wrong, and there is little we can do about this without deep research, Iām afraid. But just to be sure it is not just some configuration issue: is the adapter listed here?
ip l
ip a
I wrote about this problem here: Can not activate eth0 - Allwinner sunxi - Armbian Community Forums
But what is about odroid, pine64 oder banana pi? Do I get there full 1GB network or are they also sharing with USB as raspy 3?
Depends on the exact model, but recent Odroids (N2, C4, M1) and PINE64 (ROCKPro64, Quartz64) SBCs have full GiB Ethernet support. AFAIK this internal USB-Ethernet bus combination is an RPi-only thing.
and not valid for RPi4
thanks for the info! So it makes no sense to buy the expansive raspi, but pine or odroid. Or are there any drawbacks?
It really depends on your use case and many other factors, impossible to say generally. All SBCs provide different features, different performance have have different mainline kernel/userland support for GPU stuff and such. Generally RPi has the best maintained kernel and GUI/graphics/camera software support, but that may not be relevant for you.
but good to know.
If I want to set up a backup server with dietpi and urbackup, what could be the ābestā choice?
I think any of the named ones (and many others) will do equally good then, as all of them have native GiB when Ethernet and USB 3 support. CPU and RAM performance AFAIK is not the limiting factor. You may prefer an SBC with integrated eMMC or eMMC slot for the OS, which is much more reliable and durable compared to an SD card, but also more expensive. RPiās do not have it, which is one of their major weakness. But they support USB boot very well to compensate that.
In case CPU/RAM performance is relevant (as said for a backup server usually not), you may have a look at our community benchmarks: DietPi-Survey statistics
thanks, thats a good basis to decide