Seagate's 600 Pro is the professional (read: workstation/server) version of the standard Seagate 600 SSD. Both the 600 and the 600 Pro sport the same memory controller – a Link_A_Media (LAMD) LM87800 chip, but the Seagate 600 Pro is designed for additional durability and may be the best option for certain environments.
You might not be aware that Seagate actually helped design the chip, which explains why the company is using it even after LAMD was acquired by Hynix. Both the 600 and 600 Pro use the same controller revision and both are built on 19nm NAND flash, but some of the low-level features of the two drives are rather different.
To start with, there's the capacity difference. The 480GB version of the Seagate 600 actually contains 512GB of NAND flash, but this 32GB of additional space is reserved for error correction. A buffer that size corresponds to about 6.7 per cent of the drive's total storage, and is standard for a consumer product. The 400GB Seagate 600 Pro also contains 512GB of NAND, which means Seagate has reserved a whopping 22 per cent of the drive's total flash for overprovisioning.
That might seem like overkill, but it's related to the drive's durability and warranty period. Writing to an SSD is an intrinsically destructive process – every write wears down the barrier between the NAND cells. Once a cell has been written too often, it will no longer hold a charge properly.
Modern SSDs employ a variety of sophisticated methods for slowing down the impact of this degradation, including a strategy known as wear levelling, which ensures that no one area is written too often. Two of the most basic methods of improving NAND flash longevity are binning (the process of selecting only the NAND with the best possible characteristics) and overprovisioning. Overprovisioning ensures that as cells wear out, there are unused cells available for rotating into use.
So the major differences between the Seagate 600 and the 600 Pro come down to the warranty period (five years for the 600 Pro versus three years on the basic 600) and the total amount of overprovisioning on the drive. Performance characteristics, according to Seagate, should be about the same.
We investigated the two drives using our standard suite of workstation tests, and also added two new benchmarks: The workstation-oriented VDBench, and the new PC Mark 8. In this case, VDBench will stand in for the sequential tests we normally run with AS-SSD, but we've retained the file copy tests we typically run using that test and PCMark 7 as well.
We tested the Seagate 600 Pro, the SanDisk Extreme II 480GB, and the Seagate 600 using our trusty Asus P877V-Deluxe motherboard with 8GB of DDR3-1600 RAM and an Intel Core i7-3770K CPU. The P877-V Deluxe offers multiple SATA controllers from Intel and Marvell; all of the drives were connected to Intel's 6G SATA port.
The game copying test was the one benchmark where there was a substantial differentiation. The Seagate 600's 285MBps put it midway between the Seagate 600 Pro at 335MBps, and the SanDisk Extreme II at 228MBps. Overall, the Seagate 600 was the fastest drive in the test.
Next, we have PCMark 7. The benchmark test uses real storage workloads created by recording traces of hard drive activity when playing games, loading music or video, or copying files. These traces are used to measure the performance of storage products in comprehensive real-world scenarios. Here, performance was again closely grouped. The SanDisk Extreme II scored 5373, the Seagate 600 came in at 5255, and the Seagate 600 Pro at 5277.
We eschewed AS-SSD in favour of VDBench because it evaluates some of the same characteristics of a drive, but from an enterprise perspective. The test is described as a "disk and tape I/O workload generator for verifying data integrity and measuring performance of direct attached and network connected storage on Windows, Solaris, Linux, AIX, OS/X and HP/UX."
It can test a huge variety of workloads and scenarios, including different queue depths, number of work threads, and read/write command mixtures. We measured the performance of our three drives in both sequential and random read/write scenarios, using 4K files with one thread and 32 threads of work using a queue depth of 1 and a queue depth of 32.
The Seagate 600 Pro's read performance is approximately 10 per cent lower than the Seagate 600's and roughly 15 per cent below the SanDisk Extreme II 480GB. In the 32-thread, 32 Queue Depth sequential read test, the Seagate 600 Pro hit 273MBps compared to 310MBps for the SanDisk Extreme II and 294MBps for the Seagate 600. The Seagate 600 Pro’s write performance, however, is significantly stronger than either of the other two drives, at least in some tests. Random write performance at one queue depth, using a single thread, was 66MBps for the Seagate 600 Pro, compared to 53MBps for the Seagate 600 and 48MBps for the SanDisk Extreme II.
In the four write tests we ran, the Seagate 600 Pro beat the Seagate 600 by 21 per cent and 25 per cent in the single-thread, one queue depth tests, and tied it in the 32-thread, 32 queue depth benchmarks. It hammered the SanDisk Extreme II, outpacing that drive by 8 per cent to 38 per cent depending on the specific test. The SanDisk Extreme II's 32-thread, 32 queue depth result was particularly poor; the drive turned in just 136MBps of bandwidth compared to 335MBps and 336MBps for the Seagate 600 Pro and Seagate 600 respectively. This kind of tuning makes sense. Unlike consumer drives, where the overwhelming majority of tasks involve reading data, enterprise and workstation workloads spend much more time writing.
Finally, PCMark 8's dedicated storage test is the other new addition for this review. This new benchmark has a storage-specific workload that tests both consumer and workstation applications with an emphasis on write performance for the Adobe Photoshop and Adobe Premiere tests. Like PCMark 7, this benchmark is designed to give a real-world look at an SSD's performance. All three drives effectively tied; the SanDisk Extreme II scored 4964, the Seagate 600 Pro hit 4952, and the Seagate 600 scored 4942.
So, should you consider the Seagate 600 Pro? It's fairly clear that this drive is aimed mostly at enterprise and workstation customers where its features, including the massive overprovisioning, will be well received.
The 400GB 600 Pro is priced at around the £400 mark online, although you can currently pick it up for a touch under that. That's very high for a consumer product, but less so for an enterprise SSD where long warranties and storage server performance tuning are common.
If you're an ordinary consumer, you're going to be better served by a different SSD, but if you're doing a great deal of photo editing or other write-heavy tasks, the Seagate 600 Pro may be worth the premium. The 22 per cent overprovisioning guarantees that it can handle even the heaviest tasks over the long haul.