Thread: IDE RAID
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Old September 19th 04, 11:23 PM
Tim
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Ron,

I suggest you read a lot more. Go to the intel site and ferret out the specs
on the ICH5R (82801ER chip). Read there that it states clearly that it is
Hardware Raid. Also note that the manifestation of difference between ICH5
and ICH5R is either a) if it is [perhaps] packed as a ICH5 only and so has
RAID turned off / omitted within the chip, or b) if RAID is turned on or off
by the bios at boot time - the chip will report itself as 82801EB if RAID is
off and 82801ER if RAID is on. IE ICH5R = ICH5 with RAID turned on.

The presence of RAID Firmware in the bios is no indication of
a) x86 code running in place of RAID functionality (IE soft raid) or
b) that the bios performs the RAID functionality, or
c) that all the code is x86 code - it could be a mix of x86 and whatever
code set the RAID controller uses internally for its own private firmware
that it receives on every boot from the bios.

You will see in the Intel documentation that the bios code provides specific
supporting funcitonality ie:
a) configuration and management of RAID volumes,
b) boot time access to the RAID drive, and
c) detection of RAID status in the event of failure.
The Intel documentation does not say it does anything else. IE it does not
state that it implements soft raid.

If you also read up about windows drivers you will also learn that bios
functionality is not used within Windows XP when the system is running. The
purpose of device drivers is to provide windows with software interfaces to
hardware devices that conform to a specific predefined model so that Windows
knows how to use the device correctly and automatically. The responsibility
of the device driver writer is to marry the specific device(s) to the
interface in conformance with the chosen and stated standard (IE you can
take a device that controls SATA drives and implement it as SCSI if you
wish). You are bound to have noticed that when a SATA RAID controller is
configured as RAID the device is present as a SCSI device. This is because
the native SCSI functionality is a more appropriate device model for RAID
and also that the underlying IDE and SATA interfaces are no longer visible
(see the Intel programmers reference for ICH5R for more details, or Windows
Device Manager). Any functionality provided in the bios (EG boot time
support) is minimal functionality - single threaded reading / writing to the
device, boot time disc access is not a multithreaded high performance
environment. Bios support is designed for pre-boot execution (EG checking
RAID integrity) or boot: DOS or DOS equivalent access modes (IE boot, and EG
Nortons Ghost).

Having a hardware vendor implement soft raid is unheard of here. All reviews
of such hardware would be condeming as it would be a poor perfoming,
deceitful product to claim RAID for a device when the device does not
implement it. In this country, any vendor of such a product would be legally
liable for such deceit. If you want soft raid then use the in-built Windows
soft raid functionality on *any* stock IDE or SCSI drive - no special
controller is needed.

The OP's original reference was to Intel 865 based motherboards. Making
generalisations about Intel 865 or 875 based hardware when someone somewhere
*may* have done what you claim on totally different hardware is misleading
at the least. Your references to the Promise hardware indicate your
confusion. On one hand you link to a SATA controller and the other a RAID
controller. What was your point? Which chips contains the on-board
microprocessor? Do you know? "The only difference is the onbaord firmware
chip". What is the make and model number of this chip? I suspect you are
attributing microprocessor functionality to a Flash RAM chip. Onboard or
Onchip controller that needs firmware can be configured to get their
firmware out of the BIOS chip (or the bios supplies it to them somehow).

Please, get your facts straight.

- Tim

You can find Intel at www.intel.com
for information on flash memory chips, see www.atmel.com
for information on windows device driver model etc. see
http://www.microsoft.com/whdc/devtools/ddk/default.mspx





"Ron Reaugh" wrote in message
news

"Leythos" wrote in message
...
In article ,
says...
The Promise chip on the mobo is nothing more than a fancy ATA
controller
chip with NO significant RAID functionality on it. All on mobo Promise

RAID
is firmware/software in x86 code hosted by the host's x86 CPU.


I would be interested in seeing where you get this information from. In
reviewing the Promise RAID 0/1 controller on the motherboard of the ASUS
PC-DL Deluxe board, I've only seen that the "driver" is a stub



Nope. No clue where you see this as there is full driver support there in
two different flavors. One RAID and one NOT.

that
allows the OS to recognise the controller (much like the SCSI RAID
Controllers that we use in HP or Compaq servers).


Any OS install requires a F6 driver load just like any other RAID card
that
the OS doesn't already know about.

All my assertions are obvious once one thinks about it. Look at the specs
for a real HW RAID like a 3Ware and notice the onboard uP.

Look at the SATA card:
http://www.promise.com/product/produ...26&familyId=3#

Look at its nearly identical sibling RAID card:
http://www.promise.com/product/produ...07&familyId=2#

Both use the same Promise SATA controller. The only significant
difference
is the onboard firmware chip, which contains x86 code. One has RAID
functionality and the other doesn't.

Such is well known.