Skip to main content

Adata Premier Pro SP920 SSD: From 128 To 1024 GB, Reviewed

A Primer: The Art Of The Platform, SMART, And You

There are a couple of ways we can tell that Adata's SP920 shares more than its controller with Crucial's M550 if you don't want to dismantle your own SSDs.

Before I popped the top on our own samples, I thought to myself, "Oh, it looks like Adata leased Micron's firmware IP for the SP920." On the next page, you'll see that both drives use the same firmware revision, MU01. The M500 is up to MU03 MU05 now, but Crucial's M550 launched on MU01. That the SP920 employs similar nomenclature was the first real indicator of something amiss. And there's more to it than that.

You see, Marvell doesn't sell firmware. It simply sells its controllers. Whether Plextor, Micron, or SanDisk chooses to implement a feature is up to each company. Generally, that also means firmware has to be developed, creating a pretty big barrier to entry before you're able to take a Marvell-powered SSD and start selling it. For Adata to come out with something new from Marvell as it waits on LSI, and to do that quickly, required getting its hands on software that was fully-baked already.

And if the matching firmware versions hadn't tipped me off, there is another surefire way to know that two Marvell-based solutions are identical: SMART data.

Self-Monitoring, Analysis and Reporting Technology data is defined by the firmware architecture. If you want to track host LBAs written or power-on time, the firmware author has to enable that functionality. Since each Marvell-based implementation is unique, we see SanDisk using certain SMART attributes, while Plextor uses others. Sometimes they overlap; sometimes they don't. Micron's own implementation tracks RAIN activity. That is, if some flash fails, RAIN uses parity to recover the information that would have been otherwise unrecoverable. Marvell's newest controllers can use parity to protect against data loss as well, but RAIN is a beast of Micron's own creation.

So, when we see this, we know what's up:

SMART Attributes (Raw Values, Decimal)Crucial M500 480 GBCrucial M550 512 GBAdata SP920 512 GB
01 Raw Read Error Rate100
05 Reallocated Sector Count100
09 Power On Hours18124783
0C Power Cycle Count502316
AB Program Fail Count000
AC Erase Fail Count000
AD Average Block Erase Count565640
AE Unexpected Power Loss361712
B4 Unused Reserve NAND Blocks821844034403
B7 SATA Interface Downshift000
B8 Error Correction Count000
BB Reported Uncorrectable Errors000
C2 Temperature171800002583197570068506180390133785
C4 Reallocation Event Count171616
C5 Current Pending Sector Count000
C6 Smart Offline Uncorrectable Error Count000
C7 Ultra DMA CRC Error Rate031
CA Percent Lifetime Used111
CE Write Error Rate000
D2 Successful RAIN Recovery Count34600
F6 Total Host Sector Writes266382043222074156794115230511355
F7 Host Program Page Count803332972652193216480081235
F8 FTL Program Page Count11815152391240751859724621376

I don't have a complete list of Micron's SMART data, but most attributes are carried over from previous models. Adata's SP920 isn't detected as exactly the same drive, so attribute names may vary based on the utility you use to view them. For example, Adata's own toolbox doesn't know the true names of each attribute. CrystalDiskMark has it mostly correct for the M500, and thus the M550 and Adata SP920. The raw values are don't change either way.

Some of these attributes are found in other drives as well. Some aren't. Intel's dalliance with Marvell's 9175 controller in the SSD 510 (a short-lived product that tided the company over until its SandForce-based solution was ready, oddly enough) featured Intel's own SMART attributes from the X25 days. And when the transition to SandForce silicon happened, those attributes followed.

So there it is. Had Adata used its own PCB and enclosure, we might not have stumbled upon this mystery. But we did, dug deeper, and the SMART data doesn't lie.

While we're here, though, let's make some observations. First, we're displaying raw decimal values. D2 is RAIN recovery count. The M550 and Adata SP920 both report values of zero. However, our 480 GB M500 didn't make it through the last year unscathed. I don't know exactly what that field represents. It could be a number of blocks, or actual data in KB or MB. Perhaps part of the flash went belly-up, prompting the drive to recalculate affected area values from parity.

And that's why it's good to have RAID support on Crucial's M550 and Adata's SP920. Micron was aggressive in transitioning to 128 Gb, 20 nm flash. While the process is much more mature today, we still like having a safety mechanism to protect our valuable information. The M500's parity ratio is 1:15, which is where the 480 GB capacity comes from. The M550 platform employs 1:127 parity to storage blocks, tying up a lot less of the drive's capacity. One gigabyte out of every 16 is reserved for RAIN on the M500. That's only one out of every 128 on the M550 and SP920.

I also love that Micron includes thorough write counter metrics. F6 is total host sector writes (think of this as the writes requested by the operating system in 512-byte sectors). Do the math for our 480 GB M500 and you get 12,702.09 GiB, or 26,638,204,322 sectors * 512 bytes each. Most drives expose this counter, and it's useful as a tool for calculating the beating a drive has endured.

Write amplification wears a drive down over time, reducing its performance. It's often a product of internal overhead, for example, shuffling a partially-filled block around during a program/erase cycle. This is normal. But it can greatly reduce the life of a client drive used for high-intensity write workloads, which is why enterprise-oriented SSDs are often substantially over-provisioned. The additional free space helps keep P/E cycles to a minimum.

We can see the result of that additional overhead through the F8 attribute, FTL program page count, which measures the number of 16 KB pages the controller has had to program. Our M500 went through difficult testing; I punished it over and over with long runs of full-span high-queue depth writes. Over its life, I've hit it with 18,028.50 GiB worth of page program operations. Compare that number to the host writes (12,702.09 GiB), and you can calculate that I've subjected the M500 to an extra 5300 GiB of shuffling and churning.

  • rolli59
    Would buy one in a heartbeat. Regardless of who makes them, nice move Adata.
    Reply
  • blackmagnum
    I prefer Sandisk, if you don't mind.
    Reply
  • cryan
    13011395 said:
    I prefer Sandisk, if you don't mind.

    The X210 is pretty awesome, but newer Marvell implementations are built with Haswell-style power features in mind. If you're looking for a drive to use in mobile applications, mind the heat and power consumption stats.

    Regards,
    Christopher Ryan
    Reply
  • rajangel
    Awhile back I purchased a few different SSD's to test out (OCZ, Crucial, Patriot, Adata). The Adata is the only one still running and was always the quickest. I don't know how this one is built, but the last Adata was built tough. The OCZ was so flimsy it felt like paper. The Crucial and the Patriot were slightly better in build quality. Now that I'm in the market for a new drive I may consider this.
    Reply
  • cryan
    13012280 said:
    Awhile back I purchased a few different SSD's to test out (OCZ, Crucial, Patriot, Adata). The Adata is the only one still running and was always the quickest. I don't know how this one is built, but the last Adata was built tough. The OCZ was so flimsy it felt like paper. The Crucial and the Patriot were slightly better in build quality. Now that I'm in the market for a new drive I may consider this.

    I have to say, the plastic or metal chassis a drive comes in doesn't mean much. In the lab, I like a nice heavy metal SSD casing, but in a laptop? You probably want a flimsy plastic chassis. It's not conductive and doesn't add much weight.


    Regards,
    Christopher Ryan
    Reply
  • rajangel
    It's a matter of opinion. I like things that are built well, and have a quality appearance. I think build quality does affect performance (read reliability). Especially when connectors/etc are cheap in construction. However, just my opinion.
    Reply
  • cryan
    13012326 said:
    It's a matter of opinion. I like things that are built well, and have a quality appearance. I think build quality does affect performance (read reliability). Especially when connectors/etc are cheap in construction. However, just my opinion.

    I agree that a substantial chassis tends to reinforce the perception of a drive's build quality, but much of the time its aesthetic. The component choice on the PCB speaks more to quality. I've seen some downright terrible drives in the fanciest of cases.

    Regards,
    Christopher Ryan

    Reply
  • rajangel
    I think there should be a restriction that prevents the article author from replying, unless there is a substantial mistake that was noted. I feel like tomshardware authors troll their own threads. This has become a problem lately. I'm at the point where I feel my business and time would be better spent on a real tech website. Tomshardware is like the Yahoo of tech sites lately.
    Reply
  • iltamies
    Typo on last page: "Adata gets a solid product able to soften the wait, and Micron (Crucial's parent company) gets to more more volume." should read "move more volume."
    Reply
  • Wisecracker
    Impressive ... power consumption is a bit high though, compared to the Samsung 120GB Evo (my current $80 fav)

    Are 'microseconds' considered 'milliseconds' ??
    Reply