Portable flash-based storage solutions are one of the growing segments in the direct-attached storage market. The emergence of 3D NAND with TLC and QLC has brought down the cost of such drives. NAND manufacturers like Western Digital, Samsung, and Crucial/Micron who also market portable SSDs have an inherent advantage in terms of vertical integration. However, the current pace of progress in flash memory has led to competitively priced offerings even from vendors who need to buy flash in the open market. ADATA and HP (Multipointe / Biwin) are two such vendors in this space. Today's review takes a look at six different portable SSDs - three each from ADATA and HP - forming the bulk of their 2020 portfolio of external flash storage solutions.

Introduction

External bus-powered storage devices have grown both in storage capacity as well as speeds over the last decade. Thanks to rapid advancements in flash technology (including the advent of 3D NAND and NVMe) as well as faster host interfaces (such as Thunderbolt 3 and USB 3.x), we now have palm-sized flash-based storage devices capable of delivering 2GBps+ speeds. While those speeds can be achieved with Thunderbolt 3, mass-market devices have to rely on USB. Entry-level USB drives utilize a flash controller with a direct USB interface, while the mid-range and high-end ones use flash packages behind either a SATA or NVMe SSD controller in conjunction with a SATA/NVMe-USB bridge. Depending on the target market, vendors use bridges with either a USB 3.2 Gen 1 or USB 3.2 Gen 2 host interface. Recently, we have seen a few devices come with USB 3.2 Gen 2x2 interfaces also.

In today's review, we take a look at almost all of the external SSD offerings in the 2020 portfolio from ADATA and HP.

HP Portable SSDs (from L to R: P500, P700, P600)

ADATA External SSDs (from L to R: SC680, SE800, SE760)

From a performance viewpoint, the devices being considered today fall under two categories that are referred to here on as 1GBps-class and 500MBps-class. The former ones use NVMe SSDs behind a USB 3.2 Gen 2 bridge, while SATA SSDs (or even direct flash packages) behind a USB 3.2 Gen 1 or Gen 2 bridge make up the latter typically. We updated our benchmark programs set for direct-attached storage devices earlier this year, and subjected the following new devices to our refreshed evaluation scheme:

• 1GBps-class:
  • ADATA SE800 1TB
  • HP P700 1TB
  • ADATA SE760 1TB
• 500MBps-class:
  • ADATA SC680 960GB
  • HP P600 500GB
  • HP P500 500GB

While the 500MBps-class drives are only compared against each other, the 1GBps-class ones are pitted against the following external SSDs that were reviewed earlier:

• Crucial Portable SSD X8 1TB
• Lexar SL100 Pro 1TB
• Samsung Portable SSD T7 Touch 1TB
• SanDisk Extreme Pro Portable SSD 1TB (2019)

A quick overview of the internal capabilities of the 1GBps-class drives is given by CrystalDiskInfo.

500MBps-Class Drives Information

ADATA SC680 960GBHP P600 500GBExpand All

Both the ADATA SC680 and HP P600 have S.M.A.R.T information being passed on from the SATA SSD side through the USB bridge. The ADATA SSD seems to have better support for monitoring compared to the P600's multiple vendor-specific fields. However, both drives supported TRIM when tested in practice.

Testbed Setup and Testing Methodology

Evaluation of DAS units on Windows is done with a Hades Canyon NUC configured as outlined below. We use one of the rear USB Type-C ports enabled by the Alpine Ridge controller for both Thunderbolt 3 and USB devices.

AnandTech DAS Testbed Configuration
Motherboard	Intel NUC8i7HVB
CPU	Intel Core i7-8809G Kaby Lake, 4C/8T, 3.1GHz (up to 4.2GHz), 14nm+, 8MB L2
Memory	Crucial Technology Ballistix DDR4-2400 SODIMM 2 x 16GB @ 16-16-16-39
OS Drive	Intel Optane SSD 800p SSDPEK1W120GA (118 GB; M.2 Type 2280 PCIe 3.0 x2 NVMe; Optane)
SATA Devices	Intel SSD 545s SSDSCKKW512G8 (512 GB; M.2 Type 2280 SATA III; Intel 64L 3D TLC)
Chassis	Hades Canyon NUC
PSU	Lite-On 230W External Power Brick
OS	Windows 10 Enterprise x64 (v1909)
Thanks to Intel for the build components

Our evaluation methodology for direct-attached storage devices adopts a judicious mix of synthetic and real-world workloads. While most DAS units targeting a particular market segment advertise similar performance numbers and also meet them for common workloads, the real differentiation is brought out on the technical side by the performance consistency metric and the effectiveness of the thermal solution. Industrial design and value-added features may also be important for certain users. The remaining sections in this review tackle all of these aspects after analyzing the features of the drives in detail.

Device Features and Characteristics

Prior to looking at the usage characteristics of the various drives, it is helpful to compare their specifications and also take a look at the internals. All the 1GBps-class drives discussed in this review adopt the strategy of placing a NVMe SSD controller behind a USB 3.2 Gen 2 bridge chip.

500MBps-Class Direct-Attached Storage Characteristics
Aspect	ADATA SC680 960GBHP P600 500GBHP P500 500GB	HP P600 500GBHP P500 500GBADATA SC680 960GB
Upstream Port	USB 3.2 Gen 1 Type-C	USB 3.2 Gen 1 Type-C
Bridge / Controller	JMicron JMS580 + Silicon Motion SM2259XT	JMicron JMS580 + HP H6158 (Silicon Motion SM2259XT?)
Flash	Micron 64L 3D TLC	Micron 64L 3D TLC
Power	Bus Powered	Bus Powered
Physical Dimensions	86.7 mm x 61 mm x 10 mm	65 mm x 92 mm x 9.2 mm
IP Rating	N/A	N/A
Weight	35 grams (without cable)	58 grams (without cable)
Cable	20 cm USB 3.2 Gen 2 Type-C to Type-C 20 cm USB 3.2 Gen 2 Type-C to Type-A	20 cm USB 3.2 Gen 2 Type-C to Type-A Type-A to Type-C Adaptor
S.M.A.R.T Passthrough	Yes	Yes
UASP Support	Yes	Yes
TRIM Passthrough	Yes	Yes

The ADATA SC680 is the lightest, coming in at 25g. The HP P500 and P600 both have a more sturdy look and feel. The cables are similar to the ones supplied with the vendor's 1GBps-class drives. The key aspect in the above table is the absence of S.M.A.R.T passthrough, TRIM support, and UASP support in the USB flash controller-based HP Portable SSD P500.

Additional details for each of the devices above, along with teardown photographs, are available in the sub-sections below.

ADATA SE800

The differentiating aspect of the ADATA SE800 is its IP68 rating and MIL-STD-810G - 516.6 shock-proofing certification. ADATA has reused the case design from the SE730 (2016 family) for the SE800. The gallery below presents some of the teardown pictures of the SE800.

There are four flash packages (two on either side) on the board. The InnoGrit 5208 (Shasta) is a PCIe 3.0 x2 DRAM-less SSD controller, and it interfaces with the flash packages on one side and an ASMedia ASM2362 USB 3.1 Gen 2 bridge on the other side. ADATA claims speeds of up to 1000 MBps for the SE800.

The internals also show two haphazardly placed thermal pads - one atop the ASMedia bridge, and another on one side of one of the ADATA flash packages. As we shall see further down, the thermal behavior of the internal board leaves a lot to be desired.

ADATA SE760

ADATA introduced the SE760 a few months after the launch of the SE800. It is a run of the mill USB 3.2 Gen 2 NVMe SSD, using separate boards for the bridge chip and the SSD, with the latter being a standard M.2 2280 NVMe SSD. The XPG SX6000 Lite used in the SE760 is a DRAM-less entry-level SSD. Unlike the SE800, the SE760 doesn't have any ingress protection, but the industrial design is sleek and attractive. The gallery below presents some of the teardown pictures of the SE760.

There are four Micron flash packages on the SX6000 Lite along with the Realtek RTS5763DL SSD controller. board. The controller is a mainstream DRAM-less offering from Realtek. The SSD interfaces with a JMicron JMS583 bridge on the main board. ADATA claims speeds of up to 1000 MBps for the SE760.

The internals show a single thermal pad on the main board. Interestingly, the only pad interfaces with empty areas of the PCB on both the main as well as the SSD gum-stick. It is evident that the thermal solution is at the wrong place, and as we shall see further down, the temperature of the board components are not pleasant when the device is subject to stressful traffic.

ADATA SC680

The SC680 is ADATA's entry level offering in the external SSD market. The slimness and lightweight nature are touted by ADATA as selling points for the drive. It integrates a SATA SSD and a USB bridge on a single PCB. The gallery below presents some of the teardown pictures of the SC680.

There are four flash packages (two on each side of the board). The controller used is the DRAM-less Silicon Motion SM2259XT, with the JMicron JMS580 doing the bridge duties. ADATA claims speeds of up to 530 MBps for the SC680.

There is no thermal solution to speak of, and the performance profile of the device leads us to believe that one might not be strictly necessary. The plastic casing ensures that any generated heat doesn't really surprise the user while handling the device.

HP P700

The P700 is HP's flagship offering in the USB external storage space. The uniqueness of the P700 (as well as the P600 discussed below) lies in its cable management design. A magnetic casing (with dimensions similar to that of the main drive) is supplied to store the cable and adaptor along with the drive itself. It is strong enough for carrying around both the drive and the cable casing together, while also being easy enough to separate for actual usage. The other interesting aspect is the adaptor - while vendors have typically provided Type-C to Type-C cables, along with a Type-C to Type-A adaptor (most Type-C to Type-A adaptors are not legitimate as per USB-IF specifications), HP supplies a Type-C to Type-A cable, along with a Type-A to Type-C adaptor. The P700 integrates a NVMe SSD and a USB bridge on a single PCB. The gallery below presents some of the teardown pictures of the P700.

There are two flash packages, Micron-branded DRAM, and a HP H8098 (re-branded Silicon Motion controller) on one side of the board. The other side is practically empty (with the blank flash package slots potentially being used in higher-capacity versions).The JMicron JMS583 performs the bridging duties. HP claims speeds of up to 1000 MBps for the P700.

A thermal pad is affixed to the inner side of the metal casing and interfaces with the flash packages as well as the SSD controller. Based on this thermal solution, we do not expect any surprises in our thermal stress tests described further down.

HP P600

The P600 targets the same market segment as that of the ADATA SC680. Similar to the SC680, it also adopts a single-PCB design for a DRAM-less SATA SSD behind a USB bridge. In terms of external appearance, it is quite similar to the P700 as can be seen from the teardown pictures below.

There are four flash packages on one side of the board. The controller used is the DRAM-less HP H6158 (re-branded Silicon Motion SM2259XT, in all likelihood), with the JMicron JMS580 doing the bridge duties. HP claims speeds of up to 560 MBps for the P600.

There are two strategically placed thermal pads attempting to cover all flash packages as well as the SSD controller. At first glance, considering the performance profile of the device, this looks acceptable. Nevertheless, the real-world performance of this thermal solution is worthy of the additional investigation reported in a later section.

HP P500

The P500 is an entry-level portable SSD with an industrial design reminiscent of the Samsung T1 from 2015. It doesn't come with magnetic cable-holder, but the cable/adaptor combination supplied alongwith is the same as the ones for the P600 and P700. The internal reveal a single-PCB design with a USB flash controller and a separate and a Type-C switch. The gallery below presents some of the teardown pictures for the P500.

There are four flash packages on one side of the board. The controller used is the HP H3808 (re-branded Silicon Motion SM3280), with the EtronTech EJ179V for implementing the Type-C support. HP claims speeds of up to 370 MBps for the P500.

There is no thermal solution necessary for this performance profile. The usage of a USB flash controller also precludes the collection of interesting device characteristics during the course of usage. It is interesting to see HP utilize a USB flash drive controller in a device marketed as a portable SSD.

Synthetic Benchmarks - ATTO and CrystalDiskMark

Most USB 3.1 Gen 2 drives with NVMe SSDs claim speeds of around 1000 MBps, and these are backed up by the ATTO benchmarks provided below. Unfortunately, these access traces are not very common in real-life scenarios.

500MBps-Class Drives Performance Benchmarks - CrystalDiskMark

ADATA SC680 960GBHP P600 500GBHP P500 500GBExpand All

CrystalDiskMark provides a better estimate of the performance range with a selected set of numbers. As evident from the screenshots above, the performance can dip to as low as 7 MBps for random writes in the HP P500. The HP P600 provides better peak numbers (554 / 491 MBps) compared to the ADATA SC680 (532 / 487 MBps). The HP P500 clocks in at 350 / 217 MBps for sequential reads and writes.

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.

The first set of graphs is for the 1GBps-class drives. The Crucial X8 wins out on the read benchmarks, but the HP P700 comes out on top in quite a few of the tests. The ADATA SE800 and SE760 come in the middle of the pack.

500MBps-Class Performance Consistency and Thermal Characteristics

ADATA SC680 960GBHP P600 500GBHP P500 500GB

The HP P500 is again a mis-fit here. The reads are very consistent across all components, but the writes average only around 120 MBps with swings between 10 and 190 MBps. This is likely due to the behavior of the USB flash controller rather than any thermal aspect. The lack of S.M.A.R.T in the HP P500 meant that we could not record any internal temperature measurements for the drive.

PCMark 10 Storage Bench - Real-World Access Traces

There are a number of storage benchmarks that can subject a device to artificial access traces by varying the mix of reads and writes, the access block sizes, and the queue depth / number of outstanding data requests. We saw results from two popular ones - ATTO, and CrystalDiskMark - in a previous section. More serious benchmarks, however, actually replicate access traces from real-world workloads to determine the suitability of a particular device for a particular workload. Real-world access traces may be used for simulating the behavior of computing activities that are limited by storage performance. Examples include booting an operating system or loading a particular game from the disk.

PCMark 10's storage bench (introduced in v2.1.2153) includes four storage benchmarks that use relevant real-world traces from popular applications and common tasks to fully test the performance of the latest modern drives:

• The Full System Drive Benchmark uses a wide-ranging set of real-world traces from popular applications and common tasks to fully test the performance of the fastest modern drives. It involves a total of 204 GB of write traffic.
• The Quick System Drive Benchmark is a shorter test with a smaller set of less demanding real-world traces. It subjects the device to 23 GB of writes.
•  
• The Data Drive Benchmark is designed to test drives that are used for storing files rather than applications. These typically include NAS drives, USB sticks, memory cards, and other external storage devices. The device is subjected to 15 GB of writes.
• The Drive Performance Consistency Test is a long-running and extremely demanding test with a heavy, continuous load for expert users. In-depth reporting shows how the performance of the drive varies under different conditions. This writes more than 23 TB of data to the drive.

Despite the data drive benchmark appearing most suitable for testing direct-attached storage, we opted to run the full system drive benchmark as part of our evaluation flow. Many of us use portable flash drives as boot drives and storage for Steam games. These types of use-cases are addressed only in the full system drive benchmark.

The Full System Drive Benchmark comprises of 23 different traces. For the purpose of presenting results, we classify them under five different categories:

• Boot: Replay of storage access trace recorded while booting Windows 10
• Creative: Replay of storage access traces recorded during the start up and usage of Adobe applications such as Acrobat, After Effects, Illustrator, Premiere Pro, Lightroom, and Photoshop.
• Office: Replay of storage access traces recorded during the usage of Microsoft Office applications such as Excel and Powerpoint.
• Gaming: Replay of storage access traces recorded during the start up of games such as Battlefield V, Call of Duty Black Ops 4, and Overwatch.
• File Transfers: Replay of storage access traces (Write-Only, Read-Write, and Read-Only) recorded during the transfer of data such as ISOs and photographs.

PCMark 10 also generates an overall score, bandwidth, and average latency number for quick comparison of different drives. The sub-sections in the rest of the page refrence the access traces specified in the PCMark 10 Technical Guide.

Booting Windows 10

The read-write bandwidth recorded for each 1GBps-class drive in the boo access trace is presented below.

The HP P700 overtages the X8 by 2MBps, while the other drives including the two new ADATA ones are clustered between 104 MBps and 112 MBps. Given the amount of data traffic involved, the gulf is unlikely to result in a major difference in the boot times with various drives. The equivalent graph for the 500MBps-class drives is shown below.

The HP P600 comes out miles ahead of the SC680, while the P500 cuts a sorry figure.

Creative Workloads

The read-write bandwidth recorded for each 1GBps-class drive in the sacr, saft, sill, spre, slig, sps, aft, exc, ill, ind, psh, and psl access traces are presented below.

Full System Drive Benchmark Bandwidth (MBps)Full System Drive Benchmark Latency (us)Full System Drive Benchmark ScoreExpand All

The HP Portable SSD P600 emerges as the best of the lot in the 500MBps-class set by a huge margin.

Miscellaneous Aspects and Concluding Remarks

The performance of the drives in various real-world access traces as well as synthetic workloads was brought out in the preceding sections. We also looked at the performance consistency for these cases. Power users may also be interested in performance consistency under worst-case conditions, as well as drive power consumption. The latter is also important when used with battery powered devices such as notebooks and smartphones. Pricing is also an important aspect. We analyze each of these in detail below.

Worst-Case Performance Consistency

Flash-based storage devices tend to slow down in unpredictable ways when subject to a large number of small-sized random writes. Many benchmarks use that scheme to pre-condition devices prior to the actual testing in order to get a worst-case representative number. Fortunately, such workloads are uncommon for direct-attached storage devices, where workloads are largely sequential in nature. Use of SLC caching as well as firmware caps to prevent overheating may cause drop in write speeds when a flash-based DAS device is subject to sustained sequential writes.

Our Sequential Writes Performance Consistency Test configures the device as a raw physical disk (after deleting configured volumes). A fio workload is set up to write sequential data to the raw drive with a block size of 128K and iodepth of 32 to cover 90% of the drive capacity. The internal temperature is recorded at either end of the workload, while the instantaneous write data rate and cumulative total write data amount are recorded at 1-second intervals.

Drive Power Consumption - CrystalDiskMark Workloads

ADATA SC680 960GBHP P600 500GBHP P500 500GB

The ADATA SC680 and the HP P600 both operate in the 1W-2.8W interval, while the HP P500 idles at around 0.7W.

Pricing

The price of flash-based storage devices tend to fluctuate quite a bit over time. However, the relative difference between different models usually doesn't change. The table below summarizes the product links and pricing for the various units discussed in the review.

External Flash Storage Devices (1GBps-Class) - Pricing
Product	Model Number	Capacity (GB)	Street Price (USD)	Price per GB (USD/GB)
ADATA SE800 1TB	ASE800-1TU32G2-CBK	1000	$130	0.13
ADATA SE760 1TB	ASE760-1TU32G2-CTI	1000	$150	0.15
Crucial Portable SSD X8 1TB	CT1000X8SSD9	1000	$150	0.15
HP P700 1TB	5MS30AA#ABC	1000	$175	0.175
Lexar SL100 Pro 1TB	LSL100P-1TBRBNA	1000	$190	0.19
Samsung Portable SSD T7 Touch 1TB	MU-PC1T0S/WW	1000	$190	0.19
SanDisk Extreme Pro Portable SSD 1TB	SDSSDE80-1T00-A25	1000	$190	0.19

As the adage goes, one gets what one pays for - power users focused on performance need to look at the bottom half of the above table. That said, the current $130 pricing for the ADATA SE800 is somewhat of a steal, considering its IP68 rating. The performance might not satisfy the enthusiasts, but casual users should be more than happy with the value delivered for the money - this is despite the flawed thermal solution.

External Flash Storage Devices (500MBps-Class) - Pricing
Product	Model Number	Capacity (GB)	Street Price (USD)	Price per GB (USD/GB)
ADATA SC680 960GB	ASC680-960GU32G2-CBK	960	$125	0.13
HP P500 500GB	7NL53AA#ABC	500	$75	0.15
HP P600 500GB	3XJ07AA#ABC	500	$80	0.16

The current pricing of the ADATA SE800 renders the ADATA SC680 unattractive for purchase. Ideally speaking, the 500MBps-class drives need to carry a significant discount over the 1GBps-class ones (given that the latter can operate quite well even with legacy ports). We do not see that with the pricing on the P500 and P600 either.

Final Words

After careful analysis of various aspects (including benchmark numbers, temperatures, power consumption, and pricing), it is clear that there is no single external SSD unit that wins on all metrics.

Casual users looking for a cheap deal could go in for the ADATA SE800 - it is the cheapest by a significant margin. However, power users would do well to stay away from it because the performance of the unit is abysmal after the SLC cache runs out, and the thermal solution is flawed. The ADATA SE760, unfortunately, doesn't merit recommendation - it doesn't stand out in any of the departments. The ADATA SE800 and SC680, along with the HP Portable SSD P600 and P500 are suitable for use with mobile devices, as they are quite power efficient. The SE800 wins out on the performance side among these four models. Based on the pricing aspect, the 500MBps-class devices should probably be avoided.

From the viewpoint of raw performance for power users with reasonable traffic requirements, the HP Portable SSD P700 is perfect. In fact, our only complaint against it is the lack of performance consistency for sustained sequential writes that span almost the entire disk. For extreme use-cases such as those, our recommendation continues to be with the SanDisk Extreme Pro Portable SSD (2019 model) despite its pricing premium over the six new external SSDs considered in this review.