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Is NVMe Really Revolutionary?
Posted by Jon Toigo on August 19, 2016
4/5 (1)

To hear advocates talk about NVMe – a de facto standard created by a group of vendors led by Intel to connect flash memory storage directly to a PCIe bus (that is, without using a SAS/SATA disk controller) – it is the most revolutionary thing that has ever happened in business computing.  While the technology provides a more efficient means to access flash memory, without passing I/O through the buffers, queues and locks associated with a SAS/SATA controller, it can be seen as the latest of a long line of bus extension technologies – and perhaps one that is currently in search of a problem to solve.

I am not against faster I/O processing, of course.  It would be great if the world finally acknowledged that storage has always been the red-headed stepchild of the Von Neumann machine.  Bus speeds and CPU processing speeds have always been capable of driving I/O faster than mechanical storage devices could handle.  That is why engineers used lots of memory – as caches ahead of disk storage or as buffers on disk electronics directly – to help mask or spoof the mismatch of speed.

latency comparison

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RAID: Parity RAID vs SSD
Posted by Anton Kolomyeytsev on October 2, 2015
4.67/5 (3)

The post describes the history of RAID 5 and how it became obsolete at some point in time, just because HDD capacity grew at an enormous rate. It happened due to the chance of failure that grew to literal imminence when spinning disks reached TB scale, because the reading speed still had the same physical limits. Basically, creating a RAID 5 even with 1 TB disks would mean certain failure of the whole array and quite soon. The array technology was “saved” by an unlikely ally – the SSD. Being faster than hard disk drives in everything, they almost nullify the chance of the abovementioned failures. The post is written for everyday reader, not just engineers, and is quite comprehensive even without special knowledge and skills.

HDD and SSD

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