WD 20TB Elements Desktop External Hard Drive - USB 3.0, Black

Product Information

In addition to their physical shape differences, USB ports on the computer side will variously support USB 3.0, 3.1, or 3.2, depending on the age of the computer and how up to date its marketing materials are. You don't have to worry about the differences among these three USB specs when looking at ordinary hard drives, though. All are inter-compatible, and you won't see a speed bump from one versus the other in the hard drive world. The drive platters' own speed is the limiter, not the flavor of USB 3. The EXOS drive beats the IronWolf Pro with a workload limit of 550TB, a significant improvement over the 300TB of its brother mechanism. These are the same workload limits as the Western Digital UltraStar DC HC560 20TB and WD Gold 20TB. But unlike the IronWolf Pro, the 20TB design shows no improvements in operational power demands over the 18TB models, and the SAS models use an extra 0.4W over the SATA versions at idle.

Doing the same calculations that we did for the IronWolf Pro, taking the 2750TB limit over five years and dividing that by the capacity, we end up with total bytes transferred of 137.5 TB per TB of drive capacity. Just how much faster is it to access data stored in flash cells? Typical read and write speeds for consumer drives with spinning platters are in the 100MBps to 200MBps range, depending on platter densities and whether they spin at 5,400rpm (more common) or 7,200rpm (less common). External SSDs offer at least twice that speed and now, often much more, with typical results on our benchmark tests in excess of 400MBps for the slowest ones. Practically speaking, this means you can move gigabytes of data (say, a 4GB feature-length film, or a year's worth of family photos) to an external SSD in seconds rather than the minutes it would take with an external spinning drive. I feel like I'm in the dark ages when installing or switching out an M.2 SSD that requires a screwdriver. Evidently, both Seagate and Western Digital did the calculations and came to the same conclusion about these devices and how much use they are likely to handle before they need replacing.

An Enterprise-class 20TB NAS drive

That's why you no longer see people experimenting by putting SSD in RAID 4 to get ridiculous speeds, like people did with SATA SSD. You simply can't do that with M.2 SSD, there's no mobo that have 6+ M.2 slots, but there's plenty of workstation solutions with many U.2 slots.There are Add-in cards that can raid together M.2 slots if you really cared about it, but realistically, I'd rather not use those if possible. The head of Seagate confirmed that Chia cryptocurrency farminghas indeed increased demand for hard drives in Q2 2021, but he implied that most of the drives used by the Chia network ( 31.8PB at press time) were bought on the secondhand market. Mosley said that Chia generated some 4%~7% of exabytes demand in the company's Q4 FY2021, so it does not make much sense to significantly boost production of hard drives, invest in additional manufacturing capacity, or rush high-capacity HDDs (e.g., 20TB models) to the market to meet this demand. The two biggest hard disk drive vendors have released 22TB hard drives with Western Digital unveiling a 26TB model in 2022 (although you won't be able to buy it as it is a data center only product). Toshiba has a 20TB CMR Hard disk drive but no plans for a 22TB one yet.

If you want 20TB drives in an array, then this is what to expect. Western Digital UltraStar DC HC560 has the same workload numbers, so the alternatives come with the same caveat. The complete reading of the drive for an integrity test once a week would use up 1,040TB per year, nearly twice the yearly limit, and that’s without any operational use. Quadruple-Level Cell (QLC): Similarly to TLC, QLC is also commonly found in consumer grade products. QLC stores 4-bits per cell and can take up to 16 levels of charge. Among the 4 variants listed, it has the highest memory density and cheapest price. However, the lower price comes at a cost in performance, reliability and endurance (up to 1K P/E).

Obviously, the ultimate goal is every actuator arm being fully independent, that would be "AWESOME". PlaneInTheSky said:There are U.2 ports on some mobo, but it's mostly servers and high-end workstations that use it.U.3 should be the "Universal Standard" that replaces SATA/SAS/nVME over PCIe. Hard drives may get you more capacity for your dollar by far, but first you need to consider a major difference in external storage these days: the hard drive versus the SSD.