Has anyone played with SATA controllers with cache, such as Acard and RocketRAID 4xxx models with RAM?

 

 

Ya know, I have a AMC/2ware PCI-X and Areca PCIe x8 caching controller, but just have not had the umph to recompile the kernel and test these puppies out.

 

I was waiting until the whole SATA on SAS port compatibility issue was worked out with the Supermicro card.

 

I do plan to get one of those ACARD Ram disks to put my Vmware images on.

Just waiting for the right circumstances.

 

Now the rocketraid 4xxx series looks nice. I think we may still have issues with the SATA on SAS port compatibility in unRAID.

 

I always had the feeling a write back cached parity drive could really improve unRAID's performance.

I always had the feeling a write back cached parity drive could really improve unRAID's performance.

 

Because the read/rewrite nature if unRAID is practically unique, a caching controller COULD have a huge impact -- one MUCH bigger than the impact of a caching controller on a more traditional system.

 

If the controller 1) reorders the cached writes intelligently to turn them into full track writes, and 2) full-track of full-cylinder read-ahead is an option, you could eliminate a large portion of the rotating media penalty that hurts unRAID disproportionally.