Either my math is bad or apparently 8*4=16

schmidtbag:

Either my math is bad or apparently 8*4=16

The connections between each disk and the chip is 4 lanes and the connection between the chip and mainboard is 16 lanes. Up to 4 random disks can run at full speed at any given time and all 8 disks can run at half speed limited by the PCI 16 lanes in the mainboard. This is much better then needing to run 32 lanes to 8 disks and having a lot of wasted bandwidth if the disk is not running full speed anyway. When raid 1 mirror is used and this card does the mirroring, only 4 disks worth of data is being transferred over the mainboard PCI at any given time anyway, but 8 disks worth of data can be transferred between the controller chip and the disks because half of the data is mirrored transfers.

Oh, lordy lordy that is fast. Add memory mapped I/O and it becomes the RAM-STICK GARGANTUA!!!

Unless they use some sort of compression method for moving data across the PCI-E bus, the limit of how much data you can move over a PCI-E x16 connection is a theoretical 32 GB/s. And most of the time there is enough overhead that you can't hit that (I think I saw a max of 29 GB/s with the 3DMark PCI-E bandwidth tester on my RTX 3090). So unless they do use compression (with a ratio of at least 1.7) to move data over the PCI-E bus, I don't see how they can hit 54 GB/s to the drives. Unless this is some artificial number based on what the switcher can handle (so onboard only).

Crazy Joe:

Unless they use some sort of compression method for moving data across the PCI-E bus, the limit of how much data you can move over a PCI-E x16 connection is a theoretical 32 GB/s. And most of the time there is enough overhead that you can't hit that (I think I saw a max of 29 GB/s with the 3DMark PCI-E bandwidth tester on my RTX 3090). So unless they do use compression (with a ratio of at least 1.7) to move data over the PCI-E bus, I don't see how they can hit 54 GB/s to the drives. Unless this is some artificial number based on what the switcher can handle (so onboard only).

It is a dual kit like the headline says. 2 cards for 1 PCI-E x16 connection each.

TLD LARS:

It is a dual kit like the headline says. 2 cards for 1 PCI-E x16 connection each.

Would have been nice if the images provided would have shown that.