---
title: "expected wiz850io ethernet speed"
url: "https://maker.wiznet.io/forum/13861"
markdown_url: "https://maker.wiznet.io/forum/13861/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "amf99"
created: "2020-05-31T16:44:05+09:00"
last_activity: "2020-06-04T05:03:43+09:00"
language: "en"
views: 1111
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# expected wiz850io ethernet speed

## Question

Asked by amf99 on 2020-05-31 in Ethernet Chips.

I have a wiz850io revision 1.0 connected to a raspberry pi zero, the spi clock is running at 33MHz. I’m using the driver that comes with the buster image. The interface between the pi and wiz850io boards is a wire wrapped interface board with connectors and the shortest possible wires (longest one is about 1/2 inch). The maximum iperf3 bandwidth is 9Mbit/s. Is this bandwidth all I should expect or should it be higher. I was hoping for at least 15Mbit/s. Is there anything that could be done to increase the bandwidth?

Thanks for any help.

## Replies

### Reply 1 by becky, 2020-06-04

The maximum speed of W5500 is 15Mbps. At this time, the speed is determined by the MCU and SPI settings. Please adjust the SPI clock speed or apply DMA.

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Source: https://maker.wiznet.io/forum/13861