In the competitive world of Solana High-Frequency Trading (HFT), the transport protocol you use to submit transactions can be the deciding factor between a profitable trade and a failed landing. While HTTPS (over TCP) has been the standard for years, QUIC (Quick UDP Internet Connections) has emerged as the superior choice for low-latency applications.
The Latency Battle: QUIC vs HTTPS
| Feature | HTTPS (TCP) | QUIC (UDP) | Winner |
|---|---|---|---|
| Handshake | 3-Way Handshake + TLS | 0-RTT or 1-RTT | QUIC |
| Packet Loss | Head-of-Line Blocking | Independent Streams | QUIC |
| Congestion Control | OS-Level (Slow) | User-Space (Fast) | QUIC |
| Connection Migration | Reconnect Required | Seamless ID-based | QUIC |
Why HTTPS Lags Behind
HTTPS relies on TCP, a protocol designed for reliability, not speed.
- Head-of-Line Blocking: If a single packet is lost, TCP halts the entire stream until that packet is retransmitted. In volatile markets with network congestion, this causes massive latency spikes.
- Handshake Overhead: Establishing a secure HTTPS connection requires multiple round-trips between client and server before any data is sent.
The QUIC Advantage
QUIC is built on UDP but adds reliability layers in user space.
- 0-RTT Handshake: If you've connected to a server before, QUIC allows you to send data immediately in the first packet, eliminating handshake latency.
- Multiplexing: QUIC handles multiple streams independently. If one stream loses a packet, others continue processing without interruption.
- Optimized for Solana: Solana's Transaction Processing Unit (TPU) natively uses QUIC to ingest transactions from leaders, making it the most direct path to the block.
Real-World Impact on Trading
For arbitrage bots and snipers, switching from HTTPS to QUIC often results in a 15-40% reduction in transaction landing time.
Pro Tip: Use AllenHark Relay to submit transactions via QUIC directly to the leader's TPU, bypassing standard RPC overhead.
Conclusion
While HTTPS is sufficient for fetching historical data or checking balances, QUIC is mandatory for transaction submission in modern Solana trading. Its ability to handle packet loss and establish connections instantly makes it the gold standard for HFT.