Intel’s Optane & DC P4800X; A Deep Dive
Date: March 26, 2017
Product Name: DC P4800X
Part Number: DC P4800X
In July of 2015 Intel and Micron’s joint venture IMFT (Intel Micron Flash Technologies) announced a breakthrough in the Non-Volatile Memory storage: 3D XPoint (pronounced ‘Three Dee Cross Point’), a technology that promised to replace NAND-based memory and take non-volatile memory to the next level. The initial promise was a new memory type with the latency and performance of Random Access Memory (aka volatile memory), drastically improved endurance compared to NAND memory, and better density than RAM. It seemed at the time like the holy grail everyone was looking for.
Those original announcements boldly proclaimed that 3D XPoint would be ‘1000 times’ faster than NAND, ‘1000 times’ the endurance of NAND, and ’10 times’ the density of RAM. It was a veritable shot across the bow of both other non-volatile memory manufacturers and volatile memory manufactures alike.
Recently we were invited to a tech conference at Intel’s offices in Folsom, California where this promise would finally be brought to fruition. As with everything storage related, time did march on and as such what we heard… did not quite live up to the initial 2015 announcements. This is however the start of a new era where the very boundary lines between volatile and non-volatile begins to blur. An era where RAM is no longer the undisputed king of performance, is no longer the only answer to increase overall I/O requests per second and lower server latency. Yes, it is indeed one bright future for Intel and a less rosy one for those traditional RAM manufacturers.
Now that the NDA is up we can give you a sneak peak at this technology and give you some insight into Intel’s plan for the future. This is a future where Optane Technology not only rewrites the requirements for a high-performance server, but also what a typical home computer needs to be equipped with in order to be considered “good enough”.
As the NDA is still not lifted on Intel’s incoming salvo for the consumer marketplace, today’s article will focus solely on what Intel’s first generation Optane can offer enterprise consumers… and boy we were impressed. Read on as we explain exactly what ‘Optane Technology’ is and what it promises to offer the Enterprise market. But first, a bit of a warm up backgrounder for everyone.
Volatile vs Non- Volatile Memory
Historically speaking memory always came in two separate and distinct groups – Volatile Memory and Non- Volatile Memory. Typical Volatile Memory is Random Access Memory and DDR4 SDRAM is the latest and greatest for servers.
DDR4 SDRAM or 4th generation Double Data Rate Synchronous Dynamic Random-Access Memory (which is a mouthful and why it is usually abbreviated as DDR4 or even just ‘RAM’) is a technology that dates back to the 1970s. While the speed and density has vastly increased over the years, at its heart ‘RAM’ is based upon a simple idea: storing a single bit of data in a capacitor. This capacitor can either be charged or discharged and this is what separates a binary 0 from a 1. However, as it relies upon capacitors the electricity leaks over a relatively short period of time making the data stored in the capacitor corrupt and unusable.
This leakage happens all the time, even when the server is powered up which is a big reason why servers make use of special ‘ECC’ DDR4 RAM. This special form of DDR4 utilizes a low level Error Correction Code to ensure that any data retrieved from the RAM is actually what was supposed to be stored. Basically this server-grade memory has an additional IC ‘chip’ on each ‘stick’ that stores a parity check that the system can use to insure that what the rest of the RAM is sending back to the host is what it was supposed to be transmitting.
All of this is why RAM is considered volatile, or ‘short term’ memory. On the positive side, RAM is incredibly fast memory storage. Its durability is also unimaginably high as very little damage is done by changing the state of each capacitor; and each Dual In-Line Memory Module (ie the ‘stick’ that the DDR4 RAM ‘chips’ are placed upon) has a fairly high density of up to 512GB.
This is actually why non-volatile memory came about: no-one wanted to have to feed in all the data needed every time someone rebooted the server. Historically the non-volatile memory of choice was Hard Disk Drives (and to a less extent Tape Drives) but in the enterprise, it has become synonymous with Solid State Drives. Now granted a Solid State Drive is in itself just a catch-all term for the various forms of this medium available but for the most part it means NAND floating gate transistor-based ‘flash’ memory.
NAND or “Not AND” floating gate transistors store data by physically changing each gate’s position so that when electricity is passed through it the resistance will vary depending on what data is ‘stored’ in that cell. Since it is a physical change the data is non-volatile and does not require constant electrical source to keep it state. This means when power to the server is (temporarily) removed the data is safe and sound. The downside is compared to ‘RAM’ the speed at which it can respond to I/O requests is snail slow.
Also compared to RAM, or even more fragile Hard Disk Drives, NAND storage is also incredibly fragile with total drive write ratings in the Petabyte or even Terabyte range. This is why Solid State Drives with a ‘RAM Stick’ interface never caught on and why RAM is still the memory speed king of the computing world. But this is where Optane steps gracefully into the equation.