Tuesday, March 01, 2016

Samsung SM951 NVMe Solid State Sisk







Subtitle: Marcus' first M.2 type M Solid State Disk 


A Computer Joke
My X58 motherboard is so old the Disk Controller copyright is from 2010 and the PCI slots are Generation 2.

Unfortunately, this is reality.   My main and backup servers are about 5 and 7 years old right now, and in computer years  (you multiply by 10, right?)  this makes both of them around retirement age.


Finite Funds
With very definitely finite funds I have the following upgrade plan

- Wait until the moment is right to rebuild a new Server
- Do some Structural upgrades right now
- If I am super clever, I'll be able to reuse this hardware in your new super dooper server


M.2 Disks

Besides differences in Length,  M.2 Solid State Hard Disks (SSD) have 2 different physical plug connectors and correspondingly different interfaces.

B Key
M Key

B Key is the older standard which plugs into a Motherboard M.2 B key slot, or via a simple cheap <20 GBP  adapter to a standard SATA disk interface

M Key is the newer standard.  It would best plug into a Motherboard M.2 M key slot, and this should be a direct link to a PCI, Generation 3, x4 lane slot.

But, did you know, you can also buy a cheap adapter card that will let your M.2 M Key disk just plug into a regular PCI slot   (x4 or better?).



This card is available from ebay for <10GBP including postage.  How do they do that!


The card I chose is even cleverer since it can mount 2 cards: a M.2 B key, outputting top right to a SATA connector,   and separately at the bottom a M.2 M key disk connection via the card slot connectors to the motherboard.

NOTE: Whilst the Samsung SM951 works well in the adapter card it can't be used to boot from because [my ancient] motherboard BIOS knows nothing about PCI disk based disks.  So you can use this as storage only when booted into Linux or Windows etc.



Some Stats


 7 Grams light







Samsung Magician did install on my Windows Server but it could not update any firmware.  A benchmark did work


 Now, an important thing about the test results.




My test computer is a circa 2009 genre, PCI slot gen 2 system.   But this disk should be interfaced to a PCI slot gen 3 system. PCI gen 3 is twice the speed of gen 2.  See here


For me I recognise that my next computer, with PCI gen 3, can potentially double the above speeds, certainly sequential reads should be above 2000 MB/sec not the 'pathetic' 1671MB/sec as shown above.

A cunning Plan



I have tested this card combination in my backup server for a few weeks, and then moved it to the main server.  It is part of a cunning [Microsoft] plan that I'll publish when fully tested and working, to improve the disk performance of the main server.

Summary
I'm very happy with this initial dip into the world of faster than SATA III, Disk Interfaces.

The biggest learning point for me is that in the future I can use any PCI gen 3 motherboard, it does not need a dedicated motherboard M.2 slot.  I can instead just use one or more regular x4 or better PCI slots with an adapter card.




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