Performance difference between LSI 9400-16i and 9460-16i in JBOD/ZFS/mdraid?

[Vatharian]

Is there any measurable performance hit in performance for using 9460 card for a software array? It's full-blown RAID card with cachevault, 4 GB of cache, etc. You can switch it to HBA mode, but does it really behave the same as simpler 9400?

 

[i386]

but does it really behave the same as simpler 9400

in jbod/it/hba mode yes

Is there any measurable performance hit in performance for using 9460 card for a software array?

Nope, controllers from the same generation use the same cpu cores & clock (and for a while now there have been raid socs with 2 cores that have enough computing power to be limited by software (proprietary raid code, unlikely as this code is probably 20+ years old) or used storage devices (ssds, hdds more likely)

 

[Vatharian]

Nope, controllers from the same generation use the same cpu cores & clock (and for a while now there have been raid socs with 2 cores that have enough computing power to be limited by software (proprietary raid code, unlikely as this code is probably 20+ years old) or used storage devices (ssds, hdds more likely)

That solves it, thank you!

I was worried that on RAID card there is an additional layer or two of processing no matter which mode it is, potentially ruining latency, but if it's the same system and SoC, then it most likely functions as modules.

 

[BLinux]

one of the key differences is the software driver. not matter what mode you run it in, RAID or HBA, the PCIe ID doesn't change. So even in HBA mode, the OS will use the driver matching the PCIe ID of the card.