Micron RealSSD P320h PCI Express SSD Review

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The Micron P320h is a rather elegant half height, half length design that will fit in a number of chassis form factors from full height ATX boxes to 2U servers or 1U servers with a riser card.  Micron provides backplane brackets for both half or full height setups (full height seen below).
Micron P320h HHHL PCIe SSD

The card has a rather small heatsink mounted atop the IDT ASIC.  Micron notes the card requires minimal airflow, specifically 1.5m/s or 300 LFM.  In a server chassis especially, this isn't an issue.  The 700GiB card we tested is compromised of a base board and two daughter cards, each with 250GiB of Micron 34nm SLC NAND on them.  In total the P320h 700GiB card has a full 1TB of memory on board, the excess of which is used for wear-leveling, parity data and maintenance.  Since the drive is based on SLC NAND technology, it has a very high lifetime endurance specification of 25PB, which is almost two times that of Intel's MLC-based SSD 910, for example.  Unfortunately, SLC NAND, as we noted earlier, also comes at a significant price premium, especially in 34nm manufacturing process technology.  In the future, Micron plans to release 25nm SLC NAND memory, which should help mitigate cost significantly.

Also on board the P320h is a little over 2GB of DDR3-1333 cache memory that is also manufactured by Micron.  There are nine 256MB chips in total here allocated for fast map table data look-ups across the NAND array.

The IDT PCI Express Flash Controller on board the P320h configures what is essentially a RAID-5 array that stripes data across all four 250GiB SSD memory modules on the card.  Micron calls their custom algorithm "RAIN" which is short for Redundant Array of Independent NAND.  RAIN employs a "7+1 RAID 5" architecture where 1 parity element is allocated for each 7 storage elements (blocks and pages).  Though the P320h employs a hardware ECC engine on board as well, this is not sufficient for data recovery and device resilience over the life of the SSD.  RAIN allows a real-time parity check and in the event a block of data is flagged with an error, the data is recovered and moved into a wear-level algorithm state.  This all happens seamlessly to the application or user, in the background. Error data is also gathered and tracked on internal logs of the drive and can be displayed via SMART health monitoring functions.

Speaking of health monitoring, Micron also offers a tool suite with the P320h called RealSSD Manager.  In addition to SMART (Self Monitoring and Analysis Reporting Technology) monitoring and message status, you can check the drive's active, current performance throughput as well as life time remaining on the drive, and controller temperature.  These tools should be particularly useful for Data Center Managers looking to see how a drive is performing under load and if current thermal management solutions are getting the job done keeping the P320h cool.  The percent life remaining monitor is a particularly simple yet hugely useful tool that we'd like to see employed on more SSD products in general moving forward.  Obviously, it takes the guess work out of SSD health status monitoring.

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4L1G8R 2 years ago

That's the first time I've seen a 670 used for memory in a test system. Stick out tongue

Or 16 GB of integrated audio memory either....lol

Dave_HH 2 years ago

Not sure I follow there, 4L1. The systems specs don't list that gibberish from what I can see.

speculatrix 2 years ago


I think you are simply seeing a mis-rendering of the specification table with one side shifted down by a row.

Dave_HH 2 years ago

Is it? I'm not seeing it that way in any browser? Which browser renders it this way?

jingles 2 years ago

Pretty amazing to see a THREE year old Fusion-io card still killing the numbers and performing as advertised. I take it you have no recent products you could have used in this comparison test?

Dave_HH 2 years ago

That is correct. Fusion-io has a great product, no doubt but we have yet to receive their ioDrive 2.

ATSP 2 years ago


P320h is AHCI based, not NVMe.

Dave_HH 2 years ago

Micron has been pretty tight-lipped about the specifics of their ASIC but I didn't say it was either, just that IDT has a family of chips that are similar to the Micron ASIC, and those are NVMe.

boogerlad one year ago

Dave, can you show us a video of the p320h booting up? I'm sorry to revive this very old comment thread, but I've been looking for native bootable pci-e ssds for a while now.

Dave_HH one year ago

[quote user="boogerlad"]

Dave, can you show us a video of the p320h booting up? I'm sorry to revive this very old comment thread, but I've been looking for native bootable pci-e ssds for a while now.


Hi BL, It's never a problem reviving a thread when you have relevant questions like this or even if you just want to comment. Smile

The reason I didn't cover boot-up with the P320h is that technically, Micron doesn't support this out of the box and I was unable to get it to function stably.  I did try and even got an image installed on it but it blue screened pretty quickly.  I could revisit it with newer drivers I suppose but it's unlikely to be different I think. 

Micron is heavily invested in supporting server configurations with this product and not as focused on it as a desktop solution.

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