How to Optimize Bittorrent for Faster Transfers

Bittorrent is a popular peer-to-peer file-sharing protocol that allows users to download files quickly by leveraging the bandwidth of multiple users. It is particularly useful for downloading large files such as the Gravitational Wave Atlas. If your Bittorrent downloads are slow, there are several ways to optimize your setup for faster transfers. Here are some practical suggestions:

Check Whether You Are Limited by Your Connection or Other Servers

• As of 2025, you should be able to download Gaia and Gravitational Wave Atlas releases at speeds of 10 MB/s or more. If your speed is significantly slower, it’s worth investigating the cause.
• You can check your download speed using any free internet speed test service.

Choose a Bittorrent Client That Supports HTTPS Backup URLs (WebSeeds)

Our torrents use HTTPS backup, with files hosted on a fast web server. If your Bittorrent client supports HTTPS backup URLs, you can download from both the web server and other users. Here is a list of Bittorrent clients that support HTTPS backup URLs as of 2025:

• aria2: A convenient command-line client, similar to wget but also supports torrents.
• Deluge: A GUI-based client.
• qBittorrent: A GUI-based client.

As of March 2025, Transmission only supports HTTP, not HTTPS backup URLs.

Use a Wired Connection Instead of Wi-Fi

Surprisingly, Wi-Fi connections can significantly slow down Bittorrent, even reducing speeds to 100 KB/s. This can occur both at home and on university campuses. The slowdown can be caused by several factors:

• Reduced speeds due to multiple clients accessing the same Wi-Fi network.
• Interference from multiple Wi-Fi networks operating in the same band.
• Network setups optimized for serving many clients with relatively slow speeds, sufficient for web access but not for large downloads.
• Increased latency in Wi-Fi packets.

Adjust Settings for the uTP Protocol

The Micro Transport Protocol (uTP) was designed to automatically slow down torrent downloads when it detects increased packet latency. This reduces the impact of Bittorrent transfers on other applications. However, with modern network hardware, this is rarely a problem. Try turning uTP off to prevent your Bittorrent client from slowing down due to occasional delayed packets.

Configure Port Forwarding

Your Bittorrent client might be using a port that is blocked by a firewall. Port forwarding allows your Bittorrent client to accept incoming connections, improving download speeds. Here’s how to set it up on a home router:

• Access your router’s settings (usually via 192.168.1.1 or 192.168.0.1).
• Find the "Port Forwarding" section and add a new rule for the port used by your Bittorrent client.
• Ensure the port is open and not blocked by your firewall.

Use a VPN for Privacy and Speed

A VPN can help protect your privacy and potentially bypass ISP throttling or firewalls you don’t control. Choose a VPN that supports P2P traffic and has high-speed servers. Note that a VPN may increase packet latency, which can lead to slower speeds.

Adjust Bandwidth Settings

Allocate sufficient bandwidth to your Bittorrent client for optimal performance:

• Set the Upload Limit to around 80% of your maximum upload speed to avoid choking your connection.
• Set the Download Limit to a high value or leave it unlimited.
• Enable Protocol Encryption to bypass ISP throttling.

Seed Responsibly

Seeding helps maintain a healthy Bittorrent ecosystem. Aim to seed at least 1:1 (upload as much as you download) to ensure faster transfers for everyone.