Rapid advancements in flash technology has coincided with the rise of USB 3.0 as an ubiquitous high-speed interface on computers. This has led to the appearance of small and affordable direct attached storage units with very high performance for day-to-day data transfer applications.
SanDisk launched the Extreme 510 Portable SSD at the 2016 CES. In terms of external appearance, it looks very similar to the Extreme 500 Portable SSD. The only differences lie in the fact that the Extreme 510 comes in only one capacity – 480GB. It also carries a IP55 rating (dust and water resistance), thanks to the rubber bumper around the unit. It is targeted towards content creators who want rugged high capacity storage in the field.
Unlike the Extreme 500 240GB sample (which was based on the SSD PLUS series with a Silicon Motion controller), the Extreme 510 480GB version is based on the Ultra II. The 480GB Ultra II sports the Marvell Renoir 88SS9189 SSD controller with SanDisk’s 2nd Gen 128Gbit 19nm TLC NAND.
Testbed Setup and Testing Methodology
Evaluation of DAS units on Windows is done with the testbed outlined in the table below. For devices with a USB 3.0 (via a Type-A interface) connection (such as the SanDisk Extreme 510 480GB that we are considering today), we utilize the USB 3.1 Type-C port enabled by the Intel Alpine Ridge controller (along with a Type-C male to Type-A female cable). The Alpine Ridge controller connects to the Z170 PCH via a PCIe 3.0 x4 link..
Performance Consistency
Yet another interesting aspect of these types of units is performance consistency. Aspects that may influence this include thermal throttling and firmware caps on access rates to avoid overheating or other similar scenarios. This aspect is an important one, as the last thing that users want to see when copying over, say, 100 GB of data to the flash drive, is the transfer rate going to USB 2.0 speeds. In order to identify whether the drive under test suffers from this problem, we instrumented our robocopy DAS benchmark suite to record the flash drive’s read and write transfer rates while the robocopy process took place in the background. For supported drives, we also recorded the internal temperature of the drive during the process. The graphs below show the speeds observed during our real-world DAS suite processing. The first three sets of writes and reads correspond to the photos suite. A small gap (for the transfer of the videos suite from the primary drive to the RAM drive) is followed by three sets for the next data set. Another small RAM-drive transfer gap is followed by three sets for the Blu-ray folder.
An important point to note here is that each of the first three blue and green areas correspond to 15.6 GB of writes and reads respectively. We do find that the temperature starts increasing sharply within the Photos suite itself. After the temperature reaches 75C (happens after more than 120GB of continuous traffic), the controller starts throttling the transfer rates.
We checked with SanDisk and confirmed that they could also reproduce the problem of extended writes triggering the thermal throttling on the controller. The water resistant coating was cited as the reason. SanDisk stressed that the Extreme 510 is best suited for consumers needing water resistance and durability / ruggedness in their portable flash drive.
Concluding Remarks
Coming to the business end of the review, the Extreme 510 builds upon the proven Extreme 500 design, and adds features required by photographers and other content creators in the field (namely, ruggedness with an IP55 rating).
The thermal throttling under sustained load is a minor point of concern. Given the 120GB of continuous traffic required to trigger the problem, it is likely that consumers are not affected by it in real-world situations. Another issue is that we were unable to confirm working TRIM, even though CrystalDiskInfo states that it is supported.
