ArkOS vs Rocknix for R36S: Which Custom Firmware is Better?
ArkOS and Rocknix are the two most popular custom firmware options for the R36S. Both replace the unreliable stock firmware with a polished, RetroArch-powered gaming experience — but they differ in approach, interface, and feature set.
Overview: What Are These Firmwares?
The R36S ships with a stock firmware that is widely considered inadequate — slow menu navigation, poor emulator configuration, and a non-existent update path. Both ArkOS and Rocknix solve these problems by replacing the entire OS with a purpose-built Linux distribution optimized for retro gaming.
ArkOS
ArkOS is a custom Linux firmware originally developed for the RK2020 and expanded to support a wide range of RK3326-based devices including the R36S. It uses EmulationStation as its frontend and RetroArch as the primary emulation backend.
ArkOS is no longer maintained. Its own wiki now opens with the notice “ATTENTION! dArkOS has replaced ArkOS. ArkOS will no longer be maintained effective immediately”, and both repositories are archived read-only — the upstream project on 30 December 2025, the R36S community build on 9 June 2026. The final images still exist, still download, and still run the hardware well. What they will not do is change again: no bugfixes, no core updates, and no way to file an issue on a read-only repository. The maintainer points R36S owners at dArkOS as the successor.
Rocknix
Rocknix (formerly known as JELOS) is a community fork that emerged from the JELOS project. It uses EmulationStation with a customized theme and RetroArch backend, similar to ArkOS. Rocknix emphasizes a clean, consistent user experience and is designed to feel like a polished product out of the box.
The Choice Is Really Three-Way, Not Two
Framing this as ArkOS against Rocknix flattens the decision that actually confronts an R36S owner. There are three images people install, and two of them are ArkOS:
- Official ArkOS — the upstream project, supporting many RK3326 devices. Largest community and the most documentation, but on the R36S it expects you to replace the device-tree (
.dtb) files by hand to match your screen panel. - Community ArkOS (maintained by AeolusUX) — a ready-to-flash image built specifically for this device. Ships every R36S panel's
.dtband adds a Panel Picker Mode that identifies your screen for you. - Rocknix — the continuation of JELOS, which also generally includes the right device-tree files, so it usually boots without manual work.
That distinction matters more than any feature row below, because the most common way an R36S install fails is a black screen at first boot — a panel and .dtb mismatch, not a broken device. Whichever image spares you that step is the one to start with. Our firmware guide covers the flashing process for each.
Feature Comparison
Read the table below with one thing in mind: most rows are identical. That is the finding, not a failure of the comparison. Both are Linux distributions running EmulationStation over RetroArch, both scrape artwork, both do RetroAchievements and netplay, both accept a Wi-Fi dongle for updates. Anyone claiming a large capability gap between them is selling something.
The differences that survive scrutiny are about philosophy: how much the firmware decides for you, and how often it changes under you.
| Feature | ArkOS | Rocknix |
|---|---|---|
| Frontend | EmulationStation | EmulationStation |
| Emulation backend | RetroArch + standalones | RetroArch + standalones |
| Default theme | Art Book Next | Art Book Next (customized) |
| OTA updates | Yes (via Wi-Fi USB adapter) | Yes (via Wi-Fi USB adapter) |
| RetroAchievements | Yes | Yes |
| Netplay | Yes | Yes |
| Scraper (built-in) | Yes (ScreenScraper) | Yes (ScreenScraper) |
| SSH access | Yes | Yes |
| Standalone emulators | PPSSPP, Drastic, more | PPSSPP, Drastic, more |
| Update frequency | None — discontinued (final release 2.0, late 2025) | Active, roughly monthly |
| R36S-specific support | Excellent in the community build; official needs manual .dtb work |
Good — usually boots without manual files |
| PortMaster folder | /roms/tools/PortMaster/ |
/roms/ports/PortMaster/ |
| Community size | Large | Medium |
Performance
Both firmware versions are built on the same Linux kernel with similar emulation backends, so raw emulation performance is essentially identical for most users. The differences lie in how each manages system resources and which core versions are packaged.
Emulation Performance
Neither ArkOS nor Rocknix gives a measurable performance advantage for systems like GBA, SNES, or PS1. Both will run these at full speed. For borderline systems like N64 and Dreamcast, the core versions bundled in each firmware may differ slightly, giving one a small edge depending on when you install.
Pro Tip
Both ArkOS and Rocknix allow you to manually update RetroArch cores independently of the firmware version. If one firmware ships with an older core for a specific system, you can download the latest core directly within RetroArch without reinstalling the firmware.
Boot and Menu Speed
ArkOS tends to boot slightly faster, typically reaching the game menu in 25–35 seconds. Rocknix boots in 30–45 seconds. Both are acceptable, and this difference becomes negligible after the first boot since most users suspend rather than fully power off.
User Interface and Experience
ArkOS UI
ArkOS uses EmulationStation with the Art Book Next theme by default, producing a visually polished game library browser. The system menu is accessible via the Start button with clearly organized options. ArkOS adds several quality-of-life features like a quick game launcher (hold a button to resume the last game) and per-game aspect ratio shortcuts.
The ArkOS settings menu is detailed and occasionally complex — there are many options, which is powerful but can overwhelm new users. The official wiki is the best resource for understanding all the options.
Rocknix UI
Rocknix also uses EmulationStation with a clean theme and emphasizes a streamlined out-of-the-box experience. The settings menu is simpler and more organized, which many first-time custom firmware users appreciate. Advanced features are still available but hidden deeper in menus.
Rocknix's approach of "working well by default with minimal configuration" makes it particularly suitable for users who want to set up once and just play games without ongoing tuning.
Update Frequency and Community Support
ArkOS Updates
ArkOS no longer releases updates at all. Its last was version 2.0 in late 2025, and the project was formally retired the following year. Whatever state your ArkOS image is in is the state it stays in, which cuts both ways: nothing will regress under you, and nothing you hit will ever be fixed. You can still update RetroArch cores by hand from inside RetroArch, which covers the most common reason people wanted firmware updates.
The ArkOS community is active on Reddit (r/r36s, r/SBCGaming) and Discord, with experienced users available to help troubleshoot issues.
Rocknix Updates
Rocknix takes a more conservative update approach, releasing fewer but more thoroughly tested updates. This "stable release" philosophy means fewer surprise breakages but also means some bugs may persist longer before being addressed.
A Decision Procedure
Since the feature sets overlap almost completely, pick on the two axes where they genuinely diverge:
- Do you want to tinker, or to play? ArkOS exposes more and assumes you will adjust things; Rocknix decides more for you and aims to be right out of the box. Neither approach is better — they suit different evenings.
- Do you need the firmware to keep changing? This is no longer a question of pace but of whether there is a pace at all. Rocknix still ships; ArkOS has stopped. If you want a system that will pick up new cores and fixes, that decides it. If you want one that behaves the same in a year as it does today, ArkOS is frozen in a known-good state.
And a practical note that outranks both: you are not choosing once. The firmware lives on TF1 and your games live on TF2, so trying the other one costs you a spare card and twenty minutes, and your library is never at risk. That dual-slot design — covered in the dual SD card guide — is precisely what makes this a low-stakes decision. If you are undecided, flash whichever one boots on your panel first and revisit later with a second card.
Which Should You Choose?
Choose Rocknix if: you want firmware that is still being developed. It ships roughly monthly — the release before this page was last revised was 1 August 2026 — and it is the only one of the two that will still be receiving fixes next year. It also usually boots on an R36S panel without hand-swapping device-tree files, and its settings are the more streamlined of the two — fewer decisions up front, which suits anyone new to custom firmware who wants something that simply works.
Choose ArkOS if: you have it working already, or you want the Panel Picker in the community build to identify your screen for you. It is frozen, not broken, and a frozen firmware on a device this well understood is a legitimate choice — just make it knowing nothing further is coming. If you want ArkOS’s lineage with ongoing development, look at dArkOS instead.
Installation
Both firmware options are installed the same way — by flashing an image to the SD card using balenaEtcher or a similar tool. See the firmware installation guide for step-by-step instructions applicable to both.
Key installation differences:
- ArkOS: Installs to a single SD card with two partitions (system + ROMS)
- Rocknix: Same single-card layout; the ROMS partition label may differ slightly
- Both use balenaEtcher or Raspberry Pi Imager for flashing
- First boot takes 3–5 minutes to expand the filesystem