Solid-state storage vendors have increasingly embraced the notion of deploying solid-state storage as a PCI Express (PCIe) flash card inside the server. Putting flash closer to the CPU can accelerate application performance versus placing it in the storage array because it avoids the latency associated with the storage network. PCI Express SSD products use dedicated drivers to communicate using direct memory access (DMA) over the PCI bus. Besides reducing I/O latency, that enables random read and write performance orders of magnitude faster than placing flash in storage arrays.
Fusion-io remains the dominant PCIe flash vendor, but EMC is pushing hard into the space with last week’s launch of the VFCache, a PCIe flash caching product that used to be known as “Project Lightning.”
VFCache is EMC’s first PCIe flash card. VFCache consists of 300 GB PCIe cards – EMC is using single-level cell (SLC) flash from Micron and LSI – along with EMC-developed software for flash management and wear leveling. EMC says VFCache is an extension of its FAST auto-tiering software architecture, although you don’t need FAST to use VFCache.
EMC also claims that VFCache is faster than Fusion-io because VFCache handles flash management and wear leveling, while Fusion-io cards offload this to the server CPU. Fusion-io refuted this claim, saying their caching technology offers better performance by bypassing the guest operating system and the hypervisor.
Here’s a look at how SearchSolidStateStorage.com has covered this developing story.
EMC Corp. launches VFCache, its PCIe Flash caching product originally trademarked as “Project Lightning.” The announcement also made mention of its “Project Thunder” appliance with multiple flash cards that is expected to be made available in an early-access program later this year.
Pat Gelsinger, EMC's president of information infrastructure products, said during the VFCache launch announcement that the company’s move into server-side flash should not be seen as the company planning to become a server company. Gelsinger said EMC only wants to sell the flash that goes into servers.
Fusion-io CEO David Flynn said his company has a more mature flash caching product than VFCache. He also predicts that customers will not adopt EMC’s plans to extend its vendor lock to the server.
Does it matter whether EMC or Fusion-io brought the first PCIe product to the SSD market? And what differences, if any, are there between EMC’s first PCIe product and Fusion-io’s current lineup? Mark Peters, senior analyst for Enterprise Strategy Group, gives us his take on EMC, Fusion-io and their growing rivalry over PCIe.
If you want to learn more about PCIe flash, check out this tip:
Storage expert Stephen Foskett shows you how a PCIe solid-state drive can eliminate the storage network in its entirely in certain situations. He also walks you through the considerations and challenges of PCIe SSD to help you decide if it’s right for you.
This was first published in February 2012