Amulet vs AWS EFS
EFS is dependable managed NFS, designed for long-lived applications that share one live filesystem. Agent and training workloads look different: thousands of short-lived environments forked from common state, written in parallel, and merged deliberately. Amulet is built for that shape — forks that copy nothing, commits with provenance, conflict-safe publishing, and billing that only counts actively used data rather than everything you've ever stored. If you need drop-in NFS for existing applications inside one VPC, use EFS; if you're provisioning environments for agents or experiments, Amulet is faster where it matters and cheaper to hold data in.
Amulet
Amulet is a high-performance file system for parallel AI workloads: workspaces mount in under 100 ms, fork instantly without copying data, and keep a versioned, attributable history of every change.
AWS EFS
Amazon EFS is AWS's managed NFS file system: elastic shared storage that many EC2 instances or containers can mount over the network.
Capability by capability
Capability
Amulet
AWS EFS
Instant copy-on-write forks
Amulet
Yes
Fork a workspace in milliseconds; zero bytes copied until writes diverge.
AWS EFS
No
One live filesystem; copying a dataset for a second environment means copying the bytes.
Version history
Amulet
Yes
Content-addressed commits; restore any published revision exactly.
AWS EFS
Partial
AWS Backup can snapshot a filesystem on schedule; there is no commit-level history or instant restore into a writable copy.
Conflict-safe publishing
Amulet
Yes
Compare-and-swap publishes; stale writers get an explicit conflict, never silent overwrites.
AWS EFS
No
Shared NFS semantics — concurrent writers coordinate themselves.
Provenance
Amulet
Yes
Every commit records the actor, session, and run that produced it.
AWS EFS
No
CloudTrail logs API access, not which run produced which file state.
Small-file workflows
Amulet
Yes
Built for the metadata-heavy, small-file patterns of agent and code workloads — Git, grep, jq, package installs.
AWS EFS
Partial
Per-operation network round trips make metadata-heavy workloads (git status, npm install) notoriously slow on NFS.
Throughput and latency
Amulet
Yes
8.4 GB/s sustained per mount; p99 reads of 1.9 ms; mounts in under 100 ms.
AWS EFS
Partial
Elastic throughput scales with usage or provisioning, with single-digit-ms latencies typical for General Purpose mode.
Works outside one cloud
Amulet
Yes
Mount from any Linux environment — any cloud or sandbox provider.
AWS EFS
No
Practically bound to AWS networking (VPC, mount targets, DirectConnect for anything else).
Credential model
Amulet
Yes
Short-lived, workspace-scoped grants per agent; no long-lived infrastructure credentials in the agent process.
AWS EFS
Partial
Network-level access via security groups plus IAM authorization; typically instance-scoped, not per-agent.
Deduplication
Amulet
Yes
Identical file bytes are stored once per account; forks and repeated datasets share storage.
AWS EFS
No
Every copy is billed as stored bytes.
Pricing model
Amulet
Yes
$0.20/GiB-month for actively used data only — a time-weighted average, not everything ever stored. API, transfers, and metadata free. 10 GB free.
AWS EFS
Partial
~$0.30/GiB-month (Standard, us-east-1) on every stored byte, plus per-GB throughput charges on Elastic mode reads and writes.
When to choose AWS EFS
- You need drop-in NFS for existing applications already running in one AWS VPC.
- You need live shared multi-client writes to the same files with POSIX locking.
- Your organization standardizes on AWS-native services for compliance or procurement reasons.
When to choose Amulet
- You provision many environments from common data — agents, evals, fine-tuning runs — and can't afford to copy bytes per environment.
- Metadata-heavy workflows (Git, package installs, code search) are on the critical path.
- You want history: which run wrote what, from which base, restorable at any point.
- Your compute is not all in one AWS VPC — sandboxes, other clouds, ephemeral runners.
- You'd rather pay for the data you actively use than for every byte you've ever stored.
Frequently asked questions
Is Amulet cheaper than EFS?
For agent and training workloads, generally yes, for a structural reason: EFS Standard bills about $0.30 per GiB-month on every stored byte plus throughput charges, while Amulet bills $0.20 per GiB-month only on actively used data, measured as a time-weighted average, with API calls and transfers free. Cold data you keep but rarely touch costs you very little, and forks add nothing until they diverge.
Is Amulet faster than EFS for AI workloads?
For the workflows agents and training jobs actually run — small files, heavy metadata, Git operations, package installs — network-filesystem round trips make EFS a known bottleneck. Amulet is designed against exactly those patterns, with sub-100 ms mounts, p99 reads of 1.9 ms, and 8.4 GB/s sustained throughput per mount.
Can I use Amulet outside AWS?
Yes. Amulet mounts from any Linux environment, so the same workspace is reachable from any cloud, any sandbox provider, or a laptop — where EFS is effectively confined to AWS networking.
Does EFS have snapshots like Amulet's commits?
EFS integrates with AWS Backup for scheduled filesystem backups, which protects against disasters but is not a versioning workflow: restores are slow, coarse-grained, and not designed for spinning up writable copies. Amulet commits are instant, workspace-scoped, attributable to the run that made them, and restorable into a writable session at any time.