More posts, comments, votes and federation state increase database size and cache pressure.
Long-running or active instances.Hårdvarukrav för Lemmy: RAM, CPU, PostgreSQL och media
Planera Lemmy-maskinvara för RAM, CPU, PostgreSQL, pict-rs-media, federation och Docker, med praktiska rekommendationer för anpassad installation av ZimaOS.
Lemmy requirements at a glance
Lemmy's application process is lightweight, but full instance sizing must include PostgreSQL, pict-rs media handling, federation traffic and the frontend/reverse-proxy stack.
- RAM
- Official administrator docs: Lemmy uses roughly 150 MB RAM in the default Docker installation.
- CPU
- Official docs describe CPU usage as negligible for the default Lemmy process, but federation, image processing and database activity add load.
- Database
- Lemmy uses PostgreSQL in the official Docker deployment.
- Media
- pict-rs handles user-uploaded images and downloaded thumbnails, adding storage, CPU and I/O requirements.
- Federation
- Incoming/outgoing federation and scheduled ranking tasks create background network and database work.
- Best Zima starting point
- ZimaBoard 2 832 is ample for a small instance; use more RAM/storage as PostgreSQL history, media and federation grow.
From official requirements to the right setup
Do not size Lemmy from the 150 MB process number alone; include its database, media service and federation behavior.
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Official requirements
Use the official Docker deployment with Docker Compose 2.0+ and persistent PostgreSQL plus pict-rs data.
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Confirm your needs
Treat roughly 150 MB RAM and negligible CPU as the Lemmy app's default reference, not the total host footprint.
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Leave room to grow
Estimate federation scale, community activity and image/media growth because PostgreSQL and pict-rs become the larger resource consumers.
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Run it on ZimaOS
On ZimaOS, use Install Custom App with Lemmy's official Compose files, persist PostgreSQL/pict-rs volumes, configure the domain and reverse proxy, and monitor database/media growth.
Check every playback client
- Local users
- Federated communities
- PostgreSQL size
- pict-rs media growth
- Image uploads
- Reverse proxy/HTTPS
- Backup retention
- Other ZimaOS services
Official minimum requirements
Lemmy's administrator guide gives a direct process-level memory/CPU reference for the default Docker installation.
The roughly 150 MB RAM figure describes Lemmy itself, not a complete production host with PostgreSQL, pict-rs, frontend and federation traffic.
| Requirement | Official minimum | What this supports |
|---|---|---|
| Lemmy RAM reference | Roughly 150 MB | Official default Docker installation reference. |
| Lemmy CPU reference | Negligible | Official wording for the default Docker installation. |
| Database | PostgreSQL | Part of the standard Docker stack. |
| Media service | pict-rs | Processes uploaded images and external thumbnails. |
| Docker Compose | 2.0 or newer | Current Docker installation requirement. |
| Total-host RAM minimum | No universal numerical minimum published | Full host sizing depends on PostgreSQL, media and federation. |
When to upgrade your hardware
Lemmy should scale when federation, media or database growth—not the small core process—becomes the bottleneck.
PostgreSQL history grows
pict-rs media expands
Federation traffic increases
User uploads and remote thumbnails increase disk, I/O and image-processing work.
Media-heavy communities.More remote instances create additional network, database and scheduled-task work.
Public federated communities.Plan hardware growth with confidence
Scale Lemmy around PostgreSQL, media storage and federation traffic.
Put PostgreSQL on SSD-backed storage
Database latency has more impact on a growing instance than the small Lemmy process footprint.
Use SATA/NVMe with ZimaBoard 2 or SSD tiers on ZimaCube 2.Use 16 GB for a larger federated stack
Extra memory gives PostgreSQL, pict-rs and companion services more cache/headroom.
ZimaBoard 2 1664.Use multi-drive storage for media and backups
pict-rs assets and backups can outgrow the application data quickly.
ZimaCube 2 Standard.Use stronger CPU/network for a busier public instance
Image processing, federation and database activity can justify more general-purpose compute.
ZimaCube 2 Pro.Can it run on ZimaOS?
Lemmy is not currently confirmed as a public official one-click ZimaOS App Store page in the sources checked for this guide. It can be deployed through Install Custom App using Lemmy's official Docker files.
Custom install Lemmy in ZimaOS
Use Install Custom App with Lemmy's official Compose configuration, persist PostgreSQL and pict-rs data, and configure your public domain plus reverse proxy.
Custom install Lemmy in the ZimaOS app ↗Use Lemmy's official Docker installation
Current administrator documentation provides Docker Compose files and requires Compose 2.0 or newer.
Review Lemmy Docker installation ↗Size pict-rs and PostgreSQL separately
The 150 MB RAM reference applies to Lemmy itself, while media and database services have independent growth.
Review Lemmy administration ↗Choose Zima hardware for Lemmy
The Lemmy process is lightweight; database, media and federation determine the meaningful hardware tier.
Is this a small personal/community instance or a larger public federated server?
Small instance
Use ZimaBoard 2 with SSD-backed PostgreSQL and persistent media storage.
- Best starting pointZimaBoard 2 832
- More database headroomZimaBoard 2 1664
Larger public/federated instance
Use more storage and stronger general-purpose compute as PostgreSQL, media and federation grow.
- Storage-first platformZimaCube 2 Standard
- Higher-headroom platformZimaCube 2 Pro
These are workload recommendations, not official user-count or federation-throughput guarantees.
| Zima hardware | Best for | Example workload | Core configuration | Recommended boundary | Next step |
|---|---|---|---|---|---|
| ZimaBoard 2 832 | Small Lemmy instances. | Lemmy, PostgreSQL, pict-rs and modest federation/media traffic. |
|
8 GB is far above the roughly 150 MB Lemmy process reference; persist database/media on suitable storage. | Get Now |
| ZimaBoard 2 1664 | Larger small/community instances. | More PostgreSQL cache, pict-rs activity and federation headroom. |
|
16 GB is whole-stack headroom, not an official Lemmy minimum. | Get Now |
| ZimaCube 2 Standard | Media/history-heavy Lemmy instances. | Larger pict-rs media, PostgreSQL backups and broader NAS storage. |
|
Choose it primarily for storage expansion. | Get Now |
| ZimaCube 2 Pro | Busier public federated instances. | Higher federation traffic, image processing, database activity and broader services. |
|
Large public instances may still need dedicated database/media infrastructure. | Get Now |
What the Press Says
Highlights from trusted reviewers worldwide.
“ZimaCube 2: Not just another NAS, tested with 25TB storage, local AI agents, 4K transcoding, and real homelab workflows.”Read full review
“The ZimaBoard 2 is a compact x86 server board that can be turned into a mini NAS, home server, media box, or self-hosting hub.”Read full review
“ZimaCube 2: A modern, high-performance NAS with plenty of room to grow—built for users who want more than basic storage.”Read full review
“Coverage focused on ZimaCube 2's open hardware foundation, no monthly fee, and self-hosting flexibility.”Read full review
Loved by the Community
Stories and reviews from people who build with Zima every day.
★★★★★
Zima Blade Little yet Powerful
Maybe I am not digital natives but I live with PCs since 12 years old in 1984 when IBM PC clone come to my home. Many years have passed and many operating system I've tried. For me Zima blade and CasaOS was a quantum leap for home PC enthusiast and server lab machine to make me stay curious and relevant for this era.
★★★★★
Very good!!
I use ZimaCube Pro as 5th Proxmox cluster node. It runs several VMs and containers, including a VM with GPU passthrough to run a self-hosted LLM. A specific LXC container runs a Samba server for NAS capabilities using four of six RAID 6 SATA HDDs with ZFS.
★★★★★
Great innovation for mini server!
It is very useful and makes a powerful mini server for many purposes, including university and college students in engineering and electronics. Thank you so much for making this server.
★★★★★
Avaliação ZimaBoard 2
Construí um servidor de uso pessoal. O desempenho está muito bom e funciona perfeitamente onde quer que eu esteja. A surpresa é não dependermos de grandes estruturas para termos nosso próprio servidor de dados. Como iniciante, estou gostando bastante do ZimaOS, pois ele é simples e eficiente.
Frequently asked questions
These answers cover Lemmy RAM, CPU, PostgreSQL, pict-rs, federation and ZimaOS deployment.
How much RAM does Lemmy need?
Lemmy's official administrator documentation says the default Docker installation uses roughly 150 MB RAM.
How much CPU does Lemmy need?
The same documentation describes default Lemmy CPU usage as negligible, but PostgreSQL, pict-rs and federation add separate load.
Which database does Lemmy use?
The standard Docker deployment uses PostgreSQL.
What is pict-rs in Lemmy?
pict-rs processes user-uploaded images and thumbnails fetched from external sites.
How much storage does Lemmy need?
No universal official disk minimum is published; PostgreSQL history, media and backups determine capacity.
Does Lemmy need a GPU?
No dedicated GPU is required for normal Lemmy operation.
Can ZimaBoard 2 run Lemmy?
Yes. The 8 GB model is ample for a small instance with properly persisted PostgreSQL and media data.
When should I choose ZimaCube 2?
When media, PostgreSQL history, backups or federation activity make larger storage and compute useful.
What sources informed this Lemmy hardware guide?
The guide uses Lemmy's current administrator and Docker installation documentation plus current Zima product pages.
