Adata SSDs have appeared in several of our deals posts in recent months. They’re competitively priced, and in the increasingly commoditized world of solid-state storage, cost-per-gigabyte is often the deciding factor. Anecdotal evidence suggests Adata SSDs are pretty reliable, too. The user reviews at Amazon and Newegg are largely positive, with relatively few reports of problems or premature failures.

The thing is, we haven’t actually tested any Adata SSDs. So when the company offered us its latest Premier Pro SP920, which is reasonably priced and available in capacities up to 1TB, we jumped at the opportunity. The SP920 would be worth looking at, we thought, and it certainly was—but not quite in the way we expected.

At first glance, the SP920 resembles pretty much every other modern SSD. The slender metal case measures 7 mm thick, and it’s adorned with a couple of couple of stickers. Nothing to see here, right?

But wait, the screws are exposed, with no threat of a voided warranty if we crack open the case and peek inside. You know you want to.

The underlying circuit board hosts a Marvell controller, Micron MLC NAND, and a side order of DRAM cache memory. That’s a common formula among smaller SSD vendors, and in this case, it’s an eerily familiar one. The Premier Pro SP920 is a dead ringer for the Crucial M550 we reviewed two weeks ago. Those two drives have the same metal case, and their circuit boards are virtually identical. Here’s our SP920 512GB sample posed next to the equivalent M550:

The SP920’s circuit board is perhaps one shade bluer, and one of the surface-mounted components in the upper right corner is different. Otherwise, these two look like twins. Both drives use the same eight-channel controller and 20-nm MLC NAND. They even have the same MU01 firmware revision number.

Now, there’s nothing wrong with the SP920 and M550 sharing the same DNA—it’s pretty good breeding stock. The flash controller is as modern as they come, at least among consumer-grade SSDs, and it accelerates 256-bit AES encryption in hardware. Tiny capacitors provide a measure of power-loss protection, allowing the drives to shut down gracefully if the power is cut unexpectedly. There’s also a layer of parity-based redundancy that guards against data loss due to physical flash failures.

Well, I think there is, anyway. Adata hasn’t confirmed the SP920’s redundancy credentials just yet. However, the M550 uses a RAID-like redundancy scheme called RAIN, and the SP920’s SMART data includes a “Successful RAIN Recovery Count” attribute. It seems like RAIN has been implemented in the Adata drive, as well.

Capacity Die config Max sequential (MB/s) Max 4KB random (IOps) Price $/GB Read Write Read Write 128GB 8 x 16GB 560 180 80,000 45,000 $89.99 $0.70 256GB 16 x 16GB 560 360 96,000 80,000 $159.99 $0.62 512GB 32 x 16GB 560 500 98,000 88,000 $334.99 $0.65 1TB 64 x 16GB 560 500 98,000 88,000 $529.99 $0.52

Like the M550, the SP920 is available in 128GB, 256GB, 512GB, and 1TB capacities. However, unlike the Crucial SSD, the Adata uses 16GB dies throughout. This fact is important because the controller can address four chips per channel across eight channels, making 32-die configs the minimum for optimal performance. At 16GB per die, the 256GB model has only 16 dies, while the 128GB version uses just eight. Those configurations don’t have enough NAND-level parallelism to exploit the controller’s full potential.

Adata’s performance specifications hint at how severe the penalty can be. The 256GB drive’s peak sequential write speed is 28% slower than that of the 512GB version. The smallest, 128GB variant is slower still. That drive also takes a big hit in random write performance.

Crucial’s old M500 is similarly handicapped, but the M550 addresses the issue by deploying 8GB NAND dies in the 128GB and 256GB capacities. This simple change doubles the number of parallel NAND dies in both models, unlocking greater performance. The 128GB drive still has lower performance ratings than its higher-capacity siblings, but most SSDs have at least one runt in the littler. The Premier Pro 920 family just has two.

To be fair, Adata’s suggested pricing accounts for the SP920’s sub-optimal NAND configurations. The 512GB and 1TB models match the street prices for the M550, while the 128GB and 256GB flavors are about $10 cheaper than their Crucial counterparts. They all have the same three-year warranty coverage. Adata doesn’t list an endurance specification for the SP920, though.

Adata distinguishes the Premier Pro SP920 from the M550 in a handful of other ways. The drive ships with a 3.5″ bay adapter and Acronis cloning software, for example. It’s supposed to work with Adata’s SSD Toolbox utility software, too.

Adata identifies this software as a key difference between the SP920 and the M550. Since we’ve been critical of Crucial’s lack of SSD software, we were eager to try the Adata utility. Unfortunately, the latest version available on the company’s website appears to be incompatible with the SP920. The drive health, total bytes written, and SMART attributes are all reported incorrectly.

Once it’s updated to support the SP920, the SSD Toolbox should be a nice perk. It offers diagnostic tests, secure erase capabilities, and both firmware and software updaters. There are provisions for older operating systems, too, including a manual TRIM function and a couple of optimization options.

The software comes with a string attached, though. An email address must be entered to download the app, and it gets added to a mailing list for Adata’s “latest news and special offers.” The initial welcome email doesn’t include an unsubscribe link, so it’s probably best to use a burner account.

Adata’s software isn’t required to monitor the Premier Pro, of course. Third-party utilities can access the drive’s SMART attributes, which track all sorts of interesting variables.

The attributes are clearly defined, unlike on the M550, whose SMART data is littered with “vendor-specific” attributes that require an accompanying decoder ring. I much prefer Adata’s straightforward approach, and it’s especially nice to see an attribute keeping tabs on the number of spare NAND blocks held in reserve.

Performance highlights

Since we only have the 512GB version of the Premier Pro SP920, we can’t explore the potential pitfalls associated with the 128GB and 256GB variants. However, we can confirm that our sample is every bit as fast as the M550 512GB. We’ve run both drives through our exhaustive suite of storage tests, and the scores were nearly identical across the board. Here are the highlights.

TR DriveBench 2.0 — Disk-intensive multitasking

This benchmark plays back the I/O associated with nearly two weeks of everyday desktop activity peppered with bouts of disk-intensive multitasking. DriveBench 2.0 is the best tool we have for assessing real-world responsiveness.

The SP920 sits in the middle of the pack overall. It matches the M550 512GB’s mean service time exactly, which isn’t all that unusual. Plenty of SSDs have the same overall score, and many others are within striking distance.

All the SSDs execute the vast majority of DriveBench requests in one millisecond or less—too little time for end users to perceive. We can also sort out the number of service times longer than 100 milliseconds, which is far more interesting data. These extremely long service times make up only a fraction of the overall total, but they’re much more likely to be noticeable.

All the Crucial SSDs log disproportionately high numbers of extremely long write service times. So does the Adata Premier Pro SP920, which exactly matches its M550 counterpart.

Now, look at the M550 256GB, which has five times more extremely long write service times than its 512GB sibling. Yikes. And that’s with a 32-die configuration. The situation would likely be much worse with the SP920 256GB, whose 16-die array is similar to that of the older M500 240GB.

Load times

Faster load times are one of the biggest benefits of solid-state storage, so we timed the Windows 7 boot process and how long it took to load a couple of game levels.

The SSDs have a big advantage over the Caviar Black mechanical drive. However, the gaps between the solid-state contenders amount to about a second at most. The SP920 doesn’t distinguish itself, and neither do any of the others. It will be interesting to see if this rough parity persists in the updated load time tests we have planned for our next-gen storage suite.

FileBench

FileBench looks at copy speeds using real-world files. Most of the file sets are self-explanatory: movies, RAW images, and MP3s. The TR set includes the image, HTML, and spreadsheet files that make up typical TR content, while the Mozilla set comprises all the files needed to compile the open-source browser. Click on the buttons below the graph to see the results for each set.





The Premier Pro performs reasonably well here. It’s not the fastest SSD in the bunch, but its copy speeds are competitive across all file types.

Once again, the Crucial M550 512GB sticks close. Although the gaps between the two are slightly wider in some of the tests, that’s more due to the fact that FileBench has greater run-to-run variance than our other benchmarks.

IOMeter

IOMeter highlights performance under a scaling load that increases the number of concurrent I/O requests. Desktop systems rarely deal with more than a few simultaneous requests, but the command queue associated with the Serial ATA spec supports up to 32. Ramping up the number of requests gives us a sense of how the Premier Pro 920 might perform in more demanding enterprise environments.

You know the deal. Click the buttons below the graph to switch between the different drives.





The SP920 and M550 512GB are right on top of each other. Neither is competitive with the best SSDs in this test, but they both hit higher I/O rates than all of the Samsung drives, at least for the lighter loads that are typical of desktop systems. The SP920 wasn’t designed for demanding enterprise loads.

Power consumption

We tested power consumption under load with IOMeter’s workstation access pattern chewing through 32 concurrent I/O requests. Idle power consumption was probed one minute after processing Windows 7’s idle tasks on an empty desktop.

Another test, another set of nearly identical results for the brothers from different mothers. The Premier Pro is pretty power-efficient overall, making it well-suited to notebooks. The differences in power consumption aren’t big enough to matter in a desktop system, though. They might not even make a meaningful difference in pint-sized systems like the Intel NUC and Gigabyte Brix Pro.