---
id: data-transfers.streams-per-file-setting
url: https://storagestudio.us/faq/data-transfers/streams-per-file-setting
category: "Data Transfers"
subcategory: "Speed and advanced options"
question: "What does Streams per file do, and why is my one big file slow?"
alt_questions:
  - "speed up a single large download"
  - "streams per file setting"
  - "why is my big download slow"
  - "multi-stream download mac"
  - "one large file transfers slowly"
short_answer: "Streams per file fetches several pieces of one large file at the same time (1–16, default 4) — the setting that speeds up a single big file. More streams help until the server or connection is the limit."
tags: ["streams", "large files", "speed"]
related: ["https://storagestudio.us/faq/data-transfers/parallel-transfers-setting", "https://storagestudio.us/faq/data-transfers/large-downloads-resume-where-they-left-off", "https://storagestudio.us/faq/data-transfers/why-is-my-transfer-slow"]
applies_to: "app>=4.16"
last_reviewed: 2026-10-01
---

# What does Streams per file do, and why is my one big file slow?

**Streams per file** splits one large file into pieces and fetches several pieces at the same time (1 to 16, default 4). That's what speeds up a single big file — **Parallel transfers** only helps when there are many files.

More streams is usually faster until the server or your connection becomes the limit; 4 is a good starting point, and going much higher rarely helps. During a large download the detail pane shows each stream, so you can tell a slow server from a stalled piece.

Related: [Parallel transfers](https://storagestudio.us/faq/data-transfers/parallel-transfers-setting) · [Large downloads that resume](https://storagestudio.us/faq/data-transfers/large-downloads-resume-where-they-left-off)