Crucial Portable SSD X6 and X8 2TB Review: QLC for Storage On-the-Go

AnandTech DAS Suite - Benchmarking for Performance Consistency

Our testing methodology for DAS units takes into consideration the usual use-case for such devices. The most common usage scenario is transfer of large amounts of photos and videos to and from the unit. Other usage scenarios include the use of the DAS as a download or install location for games and importing files directly off the DAS into a multimedia editing program such as Adobe Photoshop. Some users may even opt to boot an OS off an external storage device.

The AnandTech DAS Suite tackles the first use-case. The evaluation involves processing three different workloads:

• Photos: 15.6 GB collection of 4320 photos (RAW as well as JPEGs) in 61 sub-folders
• Videos: 16.1 GB collection of 244 videos (MP4 as well as MOVs) in 6 sub-folders
• BR: 10.7 GB Blu-ray folder structure of the IDT Benchmark Blu-ray

Each workload's data set is first placed in a 25GB RAM drive, and a robocopy command is issued to transfer it to the DAS under test (formatted in NTFS). Upon completion of the transfer (write test), the contents from the DAS are read back into the RAM drive (read test). This process is repeated three times for each workload. Read and write speeds, as well as the time taken to complete each pass are recorded. Bandwidth for each data set is computed as the average of all three passes.

Blu-ray Folder ReadBlu-ray Folder WritePhotos ReadPhotos WriteVideos ReadVideos WriteExpand All

It can be seen that there is no significant gulf in the numbers between the different units for the read workloads. For all practical purposes, the casual user will notice no difference between them in the course of normal usage, though the X6 has a narrow lead. On the writes, we see the X6 getting penalized heavily. Power users may want to dig deeper to understand the limits of each device. To address this concern, we also instrumented our evaluation scheme for determining performance consistency, covered further down in this section.

Moving on to the NVMe-class drives, we again see a similar story being played out. There is not much separating the different drives' numbers, but writes definitely seem to be an Achilles heel for the X8.

Blu-ray Folder ReadBlu-ray Folder WritePhotos ReadPhotos WriteVideos ReadVideos WriteExpand All

The results are not surprising, given the QLC flash in the drive and the fact that Crucial has optimized the drive for read-intensive workloads.

Performance Consistency

Aspects influencing the performance consistency include SLC caching and thermal throttling / firmware caps on access rates to avoid overheating. This is important for power users, as the last thing that they want to see when copying over 100s of GB of data is the transfer rate going down to USB 2.0 speeds.

In addition to tracking the instantaneous read and write speeds of the DAS when processing the AnandTech DAS Suite, the temperature of the drive was also recorded at the beginning and end of the processing. In earlier reviews, we used to track the temperature all through. However, we have observed that SMART read-outs for the temperature in NVMe SSDs using USB 3.2 Gen 2 bridge chips end up negatively affecting the actual transfer rates. To avoid this problem, we have restricted ourselves to recording the temperature at either end of the actual workloads set. The graphs below present the recorded data.

Performance Consistency and Thermal Characteristics

Crucial Portable SSD X6 2TBADATA SC680 960GBHP P600 500GBExpand All

The first three sets of writes and reads correspond to the photos suite. A small gap (for the transfer of the video suite from the internal SSD to the RAM drive) is followed by three sets for the video suite. 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. The X6 might not be the fastest drive when it comes to the writes, but, the consisntency maintained from run to run with both reads and writes is impressive. The temperature rise is only 2C after almost 250GB of traffic. The HP P600, though, fares better in both the thermal design and transfer rates perspective.

The same tests on the NVMe-class drives yielded the following results.

Performance Consistency and Thermal Characteristics

Crucial Portable SSD X8 2TBCrucial Portable SSD X8 1TBOWC Envoy Pro EX USB-C 2TBSanDisk Extreme PRO Portable SSD v2 2TB [JHL6540]SanDisk Extreme Portable SSD v2 1TBWD My Passport SSD (2020) 1TBExpand All

The graphs for the X8 1TB and 2TB versions present interesting comparison points - In the 1TB version, we see writes with big hiccups in as soon as the second pass of the first workload. For the 2TB version, this doesn't happen until the third pass of the second workload. Devices such as the OWC Envoy PRO EX USB-C and the WD My Passport SSD maintain better consistency all through.