I/O Acceleration Technology

I/O Acceleration Technology (I/OAT) is a DMA engine (an embedded DMA controller) by Intel bundled with high-end server motherboards, that offloads memory copies from the main processor by performing direct memory accesses (DMA). It is typically used for accelerating network traffic, but supports any kind of copy.

Using I/OAT for network acceleration is supported by Microsoft Windows since the release of Scalable Networking Pack for Windows Server 2003 SP1.^[1] However, it is no longer included in Windows from version 8 on-wards.^[2] It was used by the Linux kernel starting in 2006^[3] but this feature was subsequently disabled due to an alleged lack of performance benefits while creating a possibility of data corruption.^[4]

See also

• Direct memory access § DDIO

References

1. "The Cable Guy - June 2006". technet.microsoft.com. 5 May 2010. Retrieved 2018-10-08.
2. MacMichael, Duncan (20 April 2017). "NetDMA". docs.microsoft.com. Retrieved 2019-03-22.
3. "i/oat - The Linux Foundation". Archived from the original on 2016-05-05. Retrieved 2010-05-01.
4. "net_dma: mark broken".

External links

• I/OAT Home site
• Accelerating Network Receive Processing. Intel I/O Acceleration Technology // Proceedings of the Linux Symposium, 2005 (copy)
• Memory copies in hardware, LWN.net, December 7, 2005, by Jonathan Corbet
• Net-DMA Driver