![]() ![]() The card’s packaging isn’t much different than SanDisk’s typical microSD card offerings. ![]() I purchased the 64-gigabyte model, the SDSQQNR-064G-G46A. The solution: high-endurance memory cards! These cards (at least in theory) use more durable MLC or even SLC NAND Flash, which can take many more write cycles. In fact, SanDisk specifically denounces this line of cards for use in continuous-recording applications. ![]() Not only does the card have to endure temperature extremes, the constant writes can burn through the Flash’s write cycles in short order. However, not all cards are created equal.Ĭheaper cards, like SanDisk’s Ultra lineup, use cheaper TLC (triple-level cell) NAND Flash that is ill-suited to the harsh working conditions of a dashcam. Like any modern device, they generally use SD or microSD cards as their storage medium. Going from a queue depth of one to 32 could result in 10 times the transfer speeds, which is massive.UPDATE (July 19, 2020): I’ve analyzed a 128GB version of the High Endurance card, and it appears that SanDisk is using 3D TLC Flash.ĭashcams: they can be a crucial tool when reconstructing events in a vehicular incident, or a source of entertainment when watching compilations on YouTube. To use the filing cabinet analogy again, two people filing papers one by one will be much quicker than one person doing it by themselves. Having a higher queue depth often results in higher transfer speeds regardless of the block size or thread count, but a high queue depth makes an especially large difference in random workloads. You can imagine a queue as an individual worker filing documents away, and obviously, more workers mean faster filing. By default, CrystalDiskMark tests at queue depths of 1, 8, and 32, though you can manually increase the queue depth and test that way if you wish. Queue depth refers to how many queues are handling I/O requests at any given time, and with more queues open to transfer data, there's a greater potential for faster transfer speeds. Although CrystalDiskMark uses large block sizes in sequential tests and small block sizes in random tests, block size isn't necessarily indicative of sequentialness or randomness. ![]() Sequential file transfers often involve large blocks, while random workloads tend to use smaller blocks. It's basically the difference between moving one piece of paper at a time and moving a whole folder into a filing cabinet. This might seem counterintuitive, but the larger the block size, the faster the transfer speed. Depending on other factors, the performance difference between sequential and random can range from minor to extremely large. Random workloads involve data that isn't sequential or contiguous and may be spread all over the drive. In a sequential workload, the data the SSD is accessing is physically contiguous and can be accessed one after the other in a sequence (hence sequential). The main difference between these two kinds of workloads is how the data is organized. The two basic types of tests CrystalDiskMark uses are sequential and random, denoted by SEQ and RND respectively. random, block size, queue depth, and threads. CrystalDiskMark benchmarks come down to the four important testing parameters: sequential vs. Leaving it at the default of 1GB is completely fine, as it's a realistic size for a lot of data that you may access on your storage.ĬrystalDiskMark comes with four preset benchmarks, but if you look in the advanced settings, you can actually customize what the benchmark tests for and get different results. This is the file size that CrystalDiskMark creates to perform read and write tests on, and it ranges from 16MB to 64GB. Before running your tests, you'll need to set a working file size. ![]()
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