Digital cameras and camcorders employ memory cards (flash-based removable media) for storage of captured content. There are different varieties of memory cards catering to various performance levels. CompactFlash (CF) became popular in the late 90s, but, has now been overtaken by Secure Digital (SD) cards. Many computing systems (PCs as well as smartphones) also support SD / microSD cards for augmenting local storage capabilities. We recently started in-depth evaluation of the performance of various memory cards. This piece evaluates one of the highest capacity microSDXC card currently available in the market – the Elite microSDXC UHS-I 512GB version.
SD (Secure Digital) cards were introduced in 1999, as an update to the existing MultiMediaCards (MMCs). It gained traction even in areas where CompactFlash had been preferred, thanks to its small size. Its popularity is evident by the fact that it has spawned two follow-ups in the same form factor – starting with the SDSC in 1999 for capacities between 1MB and 2GB, we got SD High Capacity (SDHC) in 2006 (up to 32GB) and SD eXtended Capacity (SDXC) in 2009 (up to 2TB). The cards also come in various sizes – standard, mini, and micro. Currently, the standard and micro sizes are more popular in the market. SD’s popularity and affordability has meant that almost all consumer cameras come with a SD card slot.
Recently, we have seen a number of high-capacity microSDXC cards getting introduced. Starting with the 400GB SanDisk Ultra microSDXC UHS-I card ($153 at $0.3825/GB) introduced in August 2017, we now have the Integral 512GB and theElite 512GB in the market as well. At Computex 2018, we also saw plans from ADATA and Team Group to sell 512GB microSDXC cards. With the industry migrating to 3D NAND, the capacity per die has seen significant increase, allowing for microSDXC cards to reach these capacities. The Elite microSDXC 512GB is a UHS-I card with a Class 10 (Speed Class) / U1 (UHS Speed Class) / V10 (Video Speed Class) rating.
Elit supplied us with a retail sample of their Elite 512GB card to put through our comprehensive memory card evaluation routine. Prior to taking a look at the performance numbers, we take a look at the testbed setup and evaluation methodology.
Testbed Setup and Performance Benchmarks
Evaluation of memory cards is done on Windows with the testbed outlined in the table below. The USB 3.1 Type-C port in the testbed is enabled by the Intel Alpine Ridge controller. It connects to the Z170 PCH via a PCIe 3.0 x4 link. uSD cards utilize the Lexar Professional Workflow SR2 SDHC / SDXC UHS-II USB 3.0 Reader along with a microSD to SD adapter. For this particular review, we used the adapter supplied along with the Elite card in its retail package. The reader was placed in the Lexar Professional Workflow HR2 hub and uplinked through its USB 3.0 port with the help of a USB 3.0 Type-A female to Type-C male cable.
|AnandTech DAS Testbed Configuration|
|Motherboard||GIGABYTE Z170X-UD5 TH ATX|
|CPU||Intel Core i5-6600K|
|Memory||G.Skill Ripjaws 4 F4-2133C15-8GRR
32 GB ( 4x 8GB)
DDR4-2133 @ 15-15-15-35
|OS Drive||Samsung SM951 MZVPV256 NVMe 256 GB|
|SATA Devices||Corsair Neutron XT SSD 480 GB
Intel SSD 730 Series 480 GB
|Chassis||Cooler Master HAF XB EVO|
|PSU||Cooler Master V750 750 W|
|OS||Windows 10 Pro x64|
|Thanks to Cooler Master, GIGABYTE, G.Skill and Intel for the build components|
The full details of the reasoning behind choosing the above build components can be found here.
Elit claims speeds of up to 90 MBps, but, as the speed ratings (Class 10 / U1 / V10) indicate, this is only for the reads. Real-world write speeds are bound to be much slower. For most applications, that really doesn’t matter as long as the card is capable of sustaining the maximum possible rate at which the camera it is used in dumps data. We use fio workloads to emulate typical camera recording conditions. We run the workload on a fresh card, and also after simulating extended usage. Instantaneous bandwidth numbers are graphed. This gives an idea of performance consistency (whether there is appreciable degradation in performance as the amount of pre-existing data increases and / or the card is subject to wear and tear in terms of amount and type of NAND writes). Further justification and details of the testing parameters are available here.
With a fresh card, the writes are consistently above 20 MBps, but, after extended usage, we see dips down to the 17 – 18 MBps range. In both scenarios, the card manages to keep itself well clear of the minimum requirements for its speed rating. The read speeds meet Elit’s claims of being in the 90 MBps range. Almost all of the other microSDXC cards that we have evaluated before have higher sustained write rates, but, none of them belong to the same capacity class as the Elite card.