Sandbox Performance Across Six Dimensions | Blaxel

A coding agent depends on CPU, disk, memory, and networking at different points in a task. Whichever resource is slowest sets the pace.

That bottleneck can move several times in one run. Cloning leans on the network and filesystem. Installing packages adds CPU, random I/O, and metadata operations across thousands of files. Type checks and builds change the mix again.

A first-place result in one test tells you where a provider is strong. It does not tell you where the agent will get stuck.

StarSling’s open-source benchmark is useful because it tests six different dimensions on the same requested configuration: 4 vCPU, 8 GiB of RAM, and 40 GB of disk. Its July 23 run contains 255 metric records backed by 2,533 retained trial observations.

The leaderboard publishes one headline metric for each measured performance dimension:

Performance dimension	Headline metric	Blaxel rank
CPU	Node.js web tooling	1
Disk	fio random read, 4 KB O_DIRECT	1
Memory	STREAM Triad	2
Networking	iperf3 loopback TCP, one stream	2
System	PyBench	2
Real-world workloads	Mastra cold install	2
We ranked first on the CPU and disk headline metrics and second on memory, networking, system performance, and real-world workloads. We were the only provider in the top two across all six.

Different providers led different workloads, and several headline comparisons use small samples.

For teams building coding agents, app generators, QA agents, and agentic developer tools, every runtime bottleneck becomes product latency.

In StarSling’s run, we had no headline performance dimension below second. That consistency matters because the workload shifts between resources as the task progresses.

Read StarSling’s full benchmark write-up.