MacDrive is software from OWC Digital for using Mac-formatted drives on Windows systems. Features include support for reading and writing unencrypted, non-Fusion HFS+ volumes; formatting, partitioning, and repair; plus support for Target Disk Mode, DVD/CD, flash drives, etc. It also supports Time Machine backup browsing/copying, as well as access from Boot Camp, VMware Fusion and Parallels. A Pro version even supports SoftRAID RAID 0/RAID 1 volumes, mounts Mac sparse disk images, creates Mac ISO files, burns Mac Blu-ray discs and offers automatic file defragmentation
MacDrive 10.5.4 is priced at $49.99 for Windows 7/Server 2012 and later with a free 5-day trial available. MacDrive Pro is priced at $69.99.
MacDrive 10.5 APFS beta offers preliminary support for reading (but not writing) unencrypted APFS volumes, but the company warns about Apple’s APFS performance problems with hard drives:
While APFS does offer many advantages for Mac-formatted SSD drives, its performance on traditional platter hard drives is significantly worse. As a result, if you are going to be moving files back and forth between a Mac and a PC on a non-SSD hard drive, we recommend keeping your drive formatted as HFS+.
Keeping the drive HFS+ gives you the ability to both read and write to the disk on a PC with MacDrive, while retaining the ability for the drive to be mounted on non-High Sierra Macs.
Sonnet M.2 4×4 is a full-length, full-height PCIe card that can host up to four M.2 SSDs, which can be combined for extremely high performance. The card offers an X16 interface to the PCIe 3.0 bus with x4 bandwidth for each M.2 2280 NVMe SSD, promising extremely high performance via software RAID configurations in appropriate host systems, such as the 2019 Mac Pro. A single (non-RAID) SSD can function as a boot drive. The card is compatible with Thunderbolt PCIe expansion chassis, though maximum performance is restricted by Thunderbolt’s bandwidth limits, and similar restrictions apply to PCIe 2 slots.
Sonnet M.2 4×4 [Amazon link] is due to ship Jan. 2, 2020, list-priced at $399.99 (sans SSDs) for host computers with appropriate PCIe slots running macOS 10.13 and later, Linux Kernel 5 and later, or Windows 10.
OWC Accelsior 4M2 is a PCIe card from Other World Computing Inc. (macsales.com) that hosts four M.2 NVMe SSDs. Each SSD socket offers full x4 speed for maximum performance, and the full-height, half-length card handles PCI 3.0 at x8 speed in a 2019 Mac Pro or other computers (including slower PCIe 2.0 systems, such as classic Mac Pros).
You can boot off a single M.2 SSD, while the bundled SoftRAID app can create RAID 0, 1, 4, 5, 1+0 (10) volumes (sans support for FileVault encryption) for speeds “over 6,000 MB/s” (RAID-0, SoftRAID, two cards) with up to 8TB per card. Other features include “silent cooling via a finned heat sink cover”, an ASMedia ASM2824 controller, 380TBW endurance, and Trim support (OS-dependent).
OWC Accelsior 4M2 is priced from $479.99 with 1TB (Toshiba TLC flash) to $1,599.99 with 8 TB. (Apple charges $2,600 for 8TB storage in a 2019 Mac Pro.)
ThunderBay 4 Mini is a multi-drive storage system from Other World Computing Inc. (macsales.com) that connects to a computer via Thunderbolt — both Thunderbolt 3 models and Thunderbolt 2 models (compatible with Thunderbolt 1) are available.
Features include four 2.5″ drive bays with slide-in trays (for 6Gbps SATA SSDs or hard drives), dual Thunderbolt ports, a compact aluminum enclosure with “32.5dB cooling fan”, and SoftRAID software for combining drives in a variety of RAID configurations for improved performance and reliability (although SoftRAID is not currently compatible with FileVault 2 encryption or Fusion drive configurations).
ThunderBay 4 Mini is priced from $299.99 as a bare enclosure with SoftRAID Lite to $2,069.99 with four 2TB SSDs and the full SoftRAID XT software version, for macOS 10.13 and later.