Polynomial-C's IT blog

Mikrotik is known for its cheap 10GBit/s switches. That's the reason I bought one of these back in 2021. Although buying 10GBase-T transceivers is not that cheap, in the end I replaced my good ol' Netgear S3300-28X with the Mikrotik CRS236-24S+2Q+RM running SwOS-2.13. I know the switch can also run RouterOS but to be honest, I do not like the complexity of RouterOS, nor do I need an OS on my switch that provides lots of functionality I definitely will never use (on a switch).
Unfortunately, SwOS comes with a couple of drawbacks:

• SwOS has a limited password length: It accepts twelve chars but not 20. I didn't check if twelve really is the limit but SwOS refuses to save passwords with 20 chars.
• No ssh connections possible: All SwOS provides is a very basic http web interface.
• No https connections possible: The web-interface can only be accessed via http.

Now all these drawbacks are not present in RouterOS but still, that one is totally overloaded with functionalities one never needs in a L2 switch. Furthermore, one small misconfiguration in RouterOS and 10GBit/s transfer speeds are gone because everything gets routed over the switch CPU which is only connected to the switch chip with a 1GBit/s line.

There's one really annoying bug in SwOS-2.13 though, that only recently got confirmed by Mikrotik: The two QSFP+ ports refuse to re-establish a link connection once the remote side gets rebooted. In order to re-establish the link, I found three possible solutions:

• Reboot the switch. (most effortful solution as the entire network connected to the switch is down while the switch performs the reboot)
• Un-/replug the QSFP+-cable at the switch. (similarly effortful)
• Toggle auto negotiation from "auto" to "40G" or vice versa.

And these are the actions that do not work and will not solve the link issue:

• Reboot the remote device again.
• Un-/replug the QSFP+-cable at the remote side.
• Replace the remote NIC (if possible).
• Use a different QSFP+ cable.

Mikrotik promised a fix for a future SwOS release but I doubt this release will come anytime soon as their priority clearly is with RouterOS (where - again - this issue is not present).

Besides these issues the switch performs really great and - when using a proper transfer protocol - provides reliable 10GBit/s on all of its ports. In summary I do not regret my decision and once Mikrotik finally puts some love into SwOS again, this will become a very nice and satisfying switch for my home network.

Finally, I have my new desktop machine up and running since May 8th. As I wanted a strong machine for Gentoo development again, I went with an AMD Ryzen Threadripper PRO 3955WX which is a 16-core CPU with 32 threads running at 3.9GHz base frequency. That should be enough for the upcoming six to eight years. As I also have a couple of VMs in use on this machine, I doubled the amount of RAM compared to my old machine and now have not less than 256GB ECC-RAM to play with. That should be enough to compile Gentoo packages in a RAM-disk and run a couple of VMs at the same time.
Finding a suitable mainboard for this CPU was not hard, but obtaining the board was an adventure of its own. I opted for a Supermicro M12SWA-TF board which was announced in January 2021 with a release date of mid 2021. Unfortunately it took over a year until the board was easily available.
Having this machine now also means an end to my dual CPU-socket usage on desktop systems. I see this as an improvement because that way the mainboard has more space for other stuff and features I consider important for a modern motherboard.

I only had few annoyances while installing Gentoo on that machine. Unfortuantely I couldn't use a Gentoo-clone from my old desktop machine on the new machine because... well... -march=native on my old AMD Bulldozer CPUs produced binaries that don't run on a Threadripper CPU. That is the first time I found AMD-CPUs not being fully downward compatible.
So I went with a fully-blown stage1 installation (as I am used to do since 2003) and simply installed all packages that the world file from my old machine contained. Configuring the kernel and grub was another challenge. I somehow had trouble getting grub being recognized by UEFI and I had to take about half a dozen attempts to get a bootable kernel configured.

Speaking of this machine I should also mention Arsimael who donated an Asus Radeon RX 5700 XT GPU to this system which I would not have been able to afford otherwise.

This machine really is a beast compared to my old machine. Compiling gcc-11 went down from 1:49h to 29 minutes by less than half of the power consumption. That is simply... WOW! Now all I need to do is replacing all the loud chassis fans with Noctuas.