Does NCQ is supported in linux?
I'd like to bye Promise SATA300 TX2 plus controller and two NCQ-capable hdd's for software RAID0.
Card support NCQ. Will it works on linux ? If both hdd and controller support NCq - is it enough for NCQ or there must be support by software drive also?

I suggest a Highpoint RocketRAID 1520 or 1540 because I have a Highpoint controller that uses the HPT370 chip that works flawless. Promise controllers are Windows dependent.

If you place two hard drives in RAID-1 (mirroring), you will get the same effect as NCQ and you get fault tolerant.

NCQ will not work in RAID-0 or any setup that uses stripping.

Hm... No Promise SATA300 TX2 plus is not raid controller, so it bypass limitation "NCQ will not work in raid setup". I'd like to create software raid. And AFAIK this promise controllers is supporteb by kernel.

dah!

Promise controllers may be supported by the kernel but they are not supported well. To get the full support of the card. You have to use the drivers from Promise which only provides for Redhat and SUSE, so it limits you on what Linux distribution you can use.

If you can find a Highpoint Rocket 1520 (non-RAID version), it will be cheaper and you will not waste a feature or waste money.

From what http://linux-ata.org/sata-status.html said about Promise TX2 that includes PATA with SATA may not work. Also NCQ will not be used even though NCQ was included in the driver.

generally, true. Promise drivers have advantages in raid setup and maybe in host controller setup... Generallry, I preffer to bye Sil 3124 but it (and HPT) not available anywhere in 1000km from me I found promise 800km far from me and bye it
Also about promise PATA - info is bit outdated - there was a patch for 2/6/12 that fix that issue. However, I need only SATA for now.