intel ICH9R raid question

[ratdude747]

my intel dp35dp has the ICH9R raid chip in it.

someone in another thread mentioned it was not fakeraid.

is it fakeraid or is it hardware raid? reason I ask is since i am getting a hard drive for it soon, i want to know if it it is worth it to get 2 drives or not.

[ratdude747]

Re: intel ICH9R raid question

my research says fakeraid.

anybody care to comment?

[mockingbird]

Re: intel ICH9R raid question

It is fakeraid. ICH raid will show up as seperate drives in Linux.

[ratdude747]

Re: intel ICH9R raid question

what i thought. one hard drive it is.

[mockingbird]

Re: intel ICH9R raid question

Not to mention that without TLER/CCTL support, the drives you would have bought would be dropping out of the array like flies.

[yyonline]

Re: intel ICH9R raid question

It's software raid...but it's still faster than a single drive. My main PC is P35 chipset and has 2x velociraptors running raid.

[mockingbird]

Re: intel ICH9R raid question

It's kind of hybrid. You can kind of make it transparent to the OS because it's done from the BIOS, so you don't need to mess with it in Windows, but it's not true hardware raid because it doesn't preform like true hardware raid.

[ratdude747]

Re: intel ICH9R raid question

or essentially fakeraid.

[mockingbird]

Re: intel ICH9R raid question

The first thing that comes to mind when you say fakeraid is software based raid. Because technically, there must be some hardware acceleration in ICH raid.

[ratdude747]

Re: intel ICH9R raid question

fakeraid= sw raid with a bios-like firmware. it acts like hardware raid but the actual calculations are done by the cpu. like promise and highpoint controllers on older motherboards.

[brethin]

Re: intel ICH9R raid question

There are software based raids, like what most OS's do at the kernel level does (this is what I would call fakeraid).

There are firmware/driver based raids, which are implemented correctly according to the raid standards (I would not call these fakeraid).

And there are hardware based raids.

ICH9R is a firmware/driver based raid.

The term fakeraid was used to identify software based raids form hardware based raids.

[ratdude747]

Re: intel ICH9R raid question

Operating system-based RAID doesn't always protect the boot process and is generally impractical on desktop versions of Windows (as described above). Hardware RAID controllers are expensive and proprietary. To fill this gap, cheap "RAID controllers" were introduced that do not contain a RAID controller chip, but simply a standard disk controller chip with special firmware and drivers. During early stage bootup the RAID is implemented by the firmware; when a protected-mode operating system kernel such as Linux or a modern version of Microsoft Windows is loaded the drivers take over.
These controllers are described by their manufacturers as RAID controllers, and it is rarely made clear to purchasers that the burden of RAID processing is borne by the host computer's central processing unit, not the RAID controller itself, thus introducing the aforementioned CPU overhead from which hardware controllers don't suffer. Firmware controllers often can only use certain types of hard drives in their RAID arrays (e.g. SATA for Intel Matrix RAID), as there is neither SCSI nor PATA support in modern Intel ICH southbridges; however, motherboard makers implement RAID controllers outside of the southbridge on some motherboards. Before their introduction, a "RAID controller" implied that the controller did the processing, and the new type has become known by some as "fake RAID" even though the RAID itself is implemented correctly. Adaptec calls them "HostRAID". Various Linux distributions will refuse to work with "fake RAID".[9].

i always heard it was the driver raid that was fake because it looks like hardware to noobs but in reality is not.

if i am doing raid, i want hardware raid. not crappy sw or driver raid.

[brethin]

Re: intel ICH9R raid question

fakeraid= sw raid with a bios-like firmware. it acts like hardware raid but the actual calculations are done by the cpu. like promise and highpoint controllers on older motherboards.

You are almost correct here.

1.) fakeraid = SW raid (at the kernel level)

2.) not fakeraid = bios/firmware based raid (yes it uses the CPU)

3.) not fakeraid = hardware based raid (same as #2 but has a dedicated CPU)

[ratdude747]

Re: intel ICH9R raid question

we posted at he same time. see my new post. "fakeraid" apparently has 2 different definitions.

[mockingbird]

Re: intel ICH9R raid question

For a simple Raid 1 or Raid 0 array, bios-based raid is enough. Like I said, the more important thing is that you have the proper harddrive for raid.

For companies that want to do Raid 5, they should use controllers.

[brethin]

Re: intel ICH9R raid question

For a simple Raid 1 or Raid 0 array, bios-based raid is enough. Like I said, the more important thing is that you have the proper harddrive for raid.

For companies that want to do Raid 5, they should use controllers.

/Agree

And with the speed of todays CPU's you don't need a dedicated cpu controller for a good raid 0 or raid 1 array in a none server type application.

The harddrives are the more important part here that is for sure.

[ratdude747]

Re: intel ICH9R raid question

well, I have a 2 port 3ware card in my fileserver. I know from experience how non-hw raid bogs performance. it's not like i have a c2d or a c2q in it... all it is a pdc.

[brethin]

Re: intel ICH9R raid question

The ICH9R will blow away that 2 port 3ware card in performance with a raid 0 or raid 1 array with a Pent Dual Core and 2 good drives.

[ratdude747]

Re: intel ICH9R raid question

then which is faster? one drive or 2?

will it play nice with linux? thats my only other concern.

[mockingbird]

Re: intel ICH9R raid question

Yes. Has great compatibility with Linux, provided you configure it correctly.