The desktop Lightning XQ Four-Slot PCIe to Thunderbolt 2 Expansion Chassis from JMR Electronics is equipped with four Thunderbolt 2 ports and four PCIe slots. While this enclosure uses four Thunderbolt 2 ports to connect to your host system, each of which provides bi-directional transfer speeds of up to 20 Gb/s, it also features four full-height and full-length PCIe slots, each of which operates mechanically at x16 and electrically at x4. The advantage of this enclosure having PCIe slots is that it will allow PCIe cards to be utilized with systems that do not have any available PCIe slots, such as the 2013 Mac Pro. Common applications of PCIe expansion cards include SAS/SATA and Fibre channel host bus adapters and RAID controllers, video capture cards, audio interface cards, 10GbE network cards, RED Rocket-X cards, and more.
The four PCIe slots are also powered using two independent Thunderbolt 2 bridge circuits, each of which runs at 20 Gb/s. One Thunderbolt 2 bridge drives two of the PCIe slots, while the other Thunderbolt 2 bridge circuit powers the other two. When connecting to a Mac Pro, users will need to use two of the Lightning XQ's Thunderbolt 2 ports and two Thunderbolt 2 cables, each of which will connect two one of the Mac Pro's Thunderbolt 2 ports, with two total ports being used.
So that your bandwidth may be maximized, please ensure that each Thunderbolt 2 cable is connected to a separate Thunderbolt 2 bridge circuit on your Mac Pro. The 2013 Mac Pro comes equipped with six Thunderbolt 2 ports that are powered by three Thunderbolt 2 bridge circuits, or two ports per circuit. If multiple peripherals are connected to one circuit, then the bandwidth will be shared. Also, please bear in mind that each grouping of two PCIe slots on the Lightning XQ share one Thunderbolt 2 circuit. If only one card is installed on a dedicated circuit, it will receive the full 20 Gb/s of bandwidth of that circuit, but if a second card is installed, the bandwidth will be shared, with each card receiving 10 Gb/s. Likewise, if only one card is installed on each dedicated circuit, they will both receive the full 20 Gb/s bandwidth of each circuit. Additionally, if only one Thunderbolt 2 cable is used to connect this system to your Mac Pro, then only two of the four PCIe slots will be available. The Lightning XQ may also be installed on systems with two Thunderbolt 2 ports that share a bridge circuit, such as the MacBook Pro, but please bear in mind that the bandwidth will be shared accordingly, with a max speed of 5 Gb/s if all four PCIe slots are in use.
The JMR Lightning XQ Four-Slot PCIe to Thunderbolt 2 Expansion Chassis is powered using an internal 460W power supply. It utilizes a desktop form factor. Included with this chassis is a power cord.