The browser version you are using is not recommended for this site.
Please consider upgrading to the latest version of your browser by clicking one of the following links.

We are sorry, This PDF is available in download format only

Intel® Data Direct I/O: Frequently Asked Questions

What is Intel® Data Direct I/O?
A1: Intel® Data Direct I/O (Intel® DDIO) is a feature to be introduced on the Intel® Xeon® processor E5 series. Intel's LAN Access Division (LAD) worked for the incorporation of Intel DDIO into the Intel Xeon processor E5 because of its benefits for LAN I/O in terms of performance and system power consumption. With Intel DDIO, Intel's Ethernet server NICs and controllers talk directly to the processor cache without a detour via system memory. Intel DDIO makes the processor cache the primary destination and source of I/O data rather than main memory. By avoiding system memory, Intel DDIO reduces latency, increases system I/O bandwidth, and reduces power consumption due to memory reads and writes.

Q2: How does Intel DDIO relate to Intel Integrated I/O and PCI Express* 3.0?
A2: Integrated I/O is the new Intel Xeon processor E5 I/O architecture in which the PCI Express interface is integrated onto the processor itself rather than an I/O hub or south bridge. The Intel Xeon processor E5 Integrated I/O implements the PCI Express 3.0 specification and also incorporates Intel DDIO.

Q3: What applications benefit from Intel DDIO?
A3: Applications that reach, or nearly reach, the I/O bandwidth, as is common in telecomm, can have a 2x or more increase with Intel Xeon processor E5-based servers over the previous Intel Xeon processor 5600-based architecture because memory bandwidth is now no longer a constraint. With more common data center applications that do not reach the I/O bandwidth, the performance benefit will be relatively minor in general, but they will see a power consumption savings of up to seven watts per two-port NIC. Applications that are sensitive to latency, such as UDP-based financial trading, will see a reduction in latency on the order of about 10-15% due to Intel DDIO.

Read the full Intel® Data Direct I/O Frequently Asked Questions

Related Videos