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Fast, Cheap and Good


The super fast disk project: Part-1


There's and old engineering and contracting maxim that goes, "You can have it fast, cheap, or good; pick any two!"


In general, that has proven to be quite appropriate for zillions of situations. Most times, we in the Information Technology world are waiting around for the faster technology, and we know that when it first appears, it'll either be expensive (not cheap) or not good because of relative immaturity.  In contrast, as the technology matures, it'll become less expensive (trending toward cheap), and good because of years of refinements, but it will lose its relative speed (not fast) compared to the more recent offerings.  In contracting, we've all seen the guy who low-balls a price (cheap) but either takes forever (not fast) or does shoddy work (not good).  It's aggravating.


So, what this have to do with Ted's new series of news entries?  I'm glad you asked!


Last week my heart was all a-flutter about getting Santa to get me a Samsung SM951 M.2 AHCI drive.  Stay with me, we're almost through the alphabet...just a few more letters. Breathe! These things are sometimes called gumstick drives because they're 22mm wide and 80mm long, and pretty thin at 4mm. As I mused about the possibilities of getting 1500 Mbytes/sec performance from 500GB of drive space, I began to wonder about the future-proof possibilities of this technology.


That's when I saw the limitations of using M.2 connections. These things either take up a whole PCIe slot (just three more clusters of abbreviations/acronyms to go)  or you have to wait for some monsterous Thunderbolt external enclosure for $400 and buy all the necessary interposing pieces (in my case, a whole new computer) in order to make it work past a single gumstick of 500GB.


Since these gumsticks cost about $400 each, I figured that we were still on the early-adopter price slope of these little darlings, and that it's time to look into the recent past to see what golden opportunties have been overlooked in the blinding glare of the new gumstick technology.


Sure enough, I found the  RocketRAID 2721 and the StarTech SATSASBAY425. These two little devices form the basis for some really FAST connectivity, potentially at 2500 Mbytes/sec, at a total installed cost of somewhere around $400; that being CHEAP in this context, and the GOOD part is that it all is based on leveraging my previous investment in 500GB hybrid laptop drives.


Let me explain.  The PCIe slots in a Mac Pro are composed of lanes that are touted to be 500 Mbytes/sec each, but generally push a best case of 400 Mbytes/sec.  That's the primary reason that the 4-lane gumsticks cannot ever go any faster than 1600 Mbytes/sec in my 2010-vintage Mac Pro. The RocketRAID controller is an 8-lane device with a potential of a real-world 3200 Mbytes/sec.  It can connect to the StarTech 4-drive box that will have four 500GB hybrid drives for a total of 2000GB and 32GB of solid state cache.


Hitachi/IBM/Dell sells an enterprise grade 600GB hybrid drive with 32GB of solid state cache through discount outlets for $1000. That gets you the drive with nothing else to connect it to your computer. My GOOD solution provides all of the necessary parts, and more than 3-times the capacity for just 40-percent of the cost.


All that remains is to do all the relevant eBay deals to get this stuff into my house and into production. The website tested an SSD version of my plan at 1650 Mbytes/sec using the same controllers. I expect similar results for the working set of my audio and video files.


We'll keep you posted.  


- Ted Gary of TedLand
Sept 16, 2015


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