---
title: "W5500 spi speed"
url: "https://maker.wiznet.io/forum/15513"
markdown_url: "https://maker.wiznet.io/forum/15513/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "bahmanroshan"
created: "2025-01-14T01:28:31+09:00"
last_activity: "2025-01-14T01:28:31+09:00"
language: "en"
views: 3
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# W5500 spi speed

## Question

Asked by bahmanroshan on 2025-01-14 in Ethernet Chips.

1.What is the best speed for spi communication between Stm32 And w5500 for maximum allowded tcpip client server 1 server 8 client .

2. I make a goo 1 server and 2 client gold communication but i increase cliens to 8 set . And network missed .what is the prolled.

?

## Replies

### Reply 1 (verified answer) by WIZnet AI assistant (automated answer), 2025-01-14

To achieve the best speed for SPI communication between an STM32 and the W5500 for a setup with 1 server and 8 clients, you should consider the following: 1. **SPI Clock Speed**: The W5500 can handle SPI clock speeds up to 36 MHz. For maximum performance, you should aim to use the highest SPI clock speed that your STM32 can support while ensuring reliable communication. The test results show that with an SPI clock of 36 MHz, you can achieve a data throughput of up to 3.63 Mbps with a 16K socket buffer. 2. **Socket Buffer Size**: Ensure that the socket buffer size is optimized for your application. The W5500 has a 32kB internal Tx/Rx socket buffer memory, which can be divided among the sockets. For 8 clients, you need to allocate the buffer size efficiently to handle the data traffic. Regarding the issue of network instability when increasing the number of clients to 8, here are some potential problems and solutions: - **Buffer Overflow**: With more clients, the buffer might overflow if not managed properly. Ensure that the buffer size is adequately allocated for each client and that data is being processed and cleared efficiently. - **Network Congestion**: More clients mean more data traffic, which can lead to congestion. Ensure that your network infrastructure (e.g., routers, switches) can handle the increased load. - **SPI Communication Errors**: Check for any errors in SPI communication that might occur due to increased data traffic. Ensure that the SPI settings (clock speed, mode) are correctly configured. - **Power Supply**: Ensure that the power supply to the W5500 and STM32 is stable and sufficient to handle the increased load. By addressing these areas, you should be able to improve the performance and stability of your network setup with 1 server and 8 clients. If you need further assistance, please refer to the technical documentation available at [docs.wiznet.io](https://docs.wiznet.io). WIZnet AI Support Team

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Source: https://maker.wiznet.io/forum/15513