by Jake McTigue
The first part of this series talks a great deal about native support for NUMA in vSphere on enabled Opteron and Nehalem processor platforms. NUMA is a strong technology in and of itself, but it really starts to shine when teamed with other supporting technologies. This post covers the details of integrating next generation networking and interrupt technologies to improve storage and networking performance. The focus is on MSI-X, but future posts will cover VMDq, RSS and Multiple Queue’s in more detail, as all these technologies work closely to distribute load to multi-core CPUs and dramatically improve system performance.
MSI-X (Message Signaled Interrupts eXtended) is a new technology that replaces standard MSI as an interrupt technology. At a basic level, MSI allows PCI based devices to grab control of CPU resources through the use of an interrupt. MSI supports up to 32 of these interrupts, more than sufficient for original single cored systems. With the advent of the current age of multi-core processing, however, more interrupts have become necessary to redirect needed requests for CPU to multiple cores in a load balanced fashion (MSI-X supports 2048.) This change allows interrupts to be managed more smoothly by the system and to be handled simultaneously thereby improving latencies and lowering CPU utilization.
