Posts on Stevens Blog

RTX 3090 vs RTX PRO 4000 (Blackwell): Inference, Training, and Power Cost

Thu, 15 Jan 2026 00:00:00 +0000

I wanted to know how my local RTX 3090 (used, ~€700) compares to one or more RTX PRO 4000 Blackwell cards (145W, new ~€1400) for both LLM inference (single user / scripts / my own agents) and fine-tuning image models (AI-toolkit).

My takeaway up front: with llama.cpp the 3090 is often faster at decoding; for training the RTX PRO 4000 is slightly ahead for me. In terms of power cost per token/epoch the RTX PRO 4000 is much nicer.

Docker in a dedicated VLAN including IPv6

Sun, 17 Dec 2023 00:00:00 +0000

To test AdGuard Home I wanted to quickly spin up a Docker container. That worked right away, but it didn’t correctly log the clients’ IPv6 addresses. The solution was to place the container on the network as its own host.

Step 1: Create a VLAN on UniFi UDM‑Pro

Because containers with macvlan don’t properly use DHCP, I created a VLAN with its own IP range. In the UDM‑Pro web UI go to “Settings” → “Network” → “New Virtual Network”. Assign an IP range and a VLAN ID (I used ID 2). Set DHCP to None. Under IPv6, also assign a subnet, for example fd01::1/64.

Pulse counter

Thu, 05 Jan 2023 21:35:17 +0100

To simplify the reading and evaluation of my electricity meter, I have built a reading head using an ESP32 board and a TRCT5000 infrared sensor. Unfortunately, I still have an old, so-called “Ferraries electricity meter”. But this one has a turntable with a red mark. This makes X revolutions per kWh, in my case 75. By the duration of a revolution the momentary consumption can be calculated then.

For the sensor, I then 3D printed a housing to mount it on the meter and align it. To fix the sensor, I used adhesive tape, which is normally used to mask walls when painting, in order to get sharp edges. This tape can be removed easily and still sticks sufficiently. I designed the case in Autodesk Fusion 360.

ERCF Speedboard

Fri, 30 Dec 2022 00:00:00 +0000

Why all this?

The ERCF Speedboard is my first self-made board for my 3D printer.

I was motivated by the ERCF Easy Board ( https://github.com/Tircown/ERCF-easy-brd ). In the 3D printer itself (a Voron 2.4) I used the mainboard is the Fysetc Spider v1.1, which I recently changed from Klipper to RepRap firmware. There was no particular reason for this, I just wanted to try it out. However, I have lost the ability to communicate with the ERCF Easy Brd as a result. Of course, this is a pity, but also a new challenge.

JVC Autocal

Mon, 01 Jan 0001 00:00:00 +0000

To calibrate the JVC X5000 projector, there is a software from JVC called Autocal. Unfortunately this does not work together with the colorimeter i1Display Pro. But there is another software project ArgyllCMS which can use the sensor. So I thought some time ago, why not write a wrapper that connects the open source software with the software from JVC. The result is a DLL file, which pretends to be a Spyder colorimeter, but calls the ArgyllCMS in the background. So you can simply replace the Spyder DLL in the Autocal software and then instead of the Spyder sensor the framework is used, which can then use the i1Display Pro. The whole thing at least works reliably enough to calibrate my projector and a few other people have already used it.