Running Linux on an AMD AM2 nVidia chip ser that supports Raid 0
striping on the motherboard. Just wondering if hardware raid (SATA2) is
going to be faster that software raid and why?
Marc Perkel wrote:
> Running Linux on an AMD AM2 nVidia chip ser that supports Raid 0
> striping on the motherboard. Just wondering if hardware raid (SATA2)
> is going to be faster that software raid and why?
Beeing a consumer type board (AM2), the "raid on the motherboard" is in
99.999% of the cases just software raid implemented in their Windows
drivers, a bootup setup screen plus some BIOS magic to get the OS booting.
On Wednesday 23 August 2006 08:25, Andre Tomt wrote:
> Marc Perkel wrote:
> > Running Linux on an AMD AM2 nVidia chip ser that supports Raid 0
> > striping on the motherboard. Just wondering if hardware raid (SATA2)
> > is going to be faster that software raid and why?
>
> Beeing a consumer type board (AM2), the "raid on the motherboard" is in
> 99.999% of the cases just software raid implemented in their Windows
> drivers, a bootup setup screen plus some BIOS magic to get the OS booting.
MD has so many benefits anyway that it doesn't make sense to use anything but
the finest hardware RAID.
For starters, with Linux MD, you can RAID partitions on a disk independently,
even with different RAID types, and you can port your array to another
machine without any reconfiguration, on completely different hardware. You
can also RAID two different technologies, for example PATA and SATA, hot-add
spares, run with a deliberately failed array, build incomplete arrays (nice
if you're just about to start a RAID5 but don't have enough discs), the list
goes on..
--
Cheers,
Alistair.
Final year Computer Science undergraduate.
1F2 55 South Clerk Street, Edinburgh, UK.
Andre Tomt wrote:
> Marc Perkel wrote:
>> Running Linux on an AMD AM2 nVidia chip ser that supports Raid 0
>> striping on the motherboard. Just wondering if hardware raid (SATA2)
SATA2 has nothing to do with hardware RAID.
>> is going to be faster that software raid and why?
>
> Beeing a consumer type board (AM2), the "raid on the motherboard" is in
> 99.999% of the cases just software raid implemented in their Windows
> drivers, a bootup setup screen plus some BIOS magic to get the OS booting.
And, yeah, they're all software RAID. Also, there isn't much to be
gained from making RAID0/1 hardware. The software overhead isn't that
big. For RAID5, having XOR done in hardware helps.
--
tejun
Tejun Heo wrote:
> Andre Tomt wrote:
>> Marc Perkel wrote:
>>> Running Linux on an AMD AM2 nVidia chip ser that supports Raid 0
>>> striping on the motherboard. Just wondering if hardware raid (SATA2)
>
> SATA2 has nothing to do with hardware RAID.
>
>>> is going to be faster that software raid and why?
>>
>> Beeing a consumer type board (AM2), the "raid on the motherboard" is
>> in 99.999% of the cases just software raid implemented in their
>> Windows drivers, a bootup setup screen plus some BIOS magic to get
>> the OS booting.
>
> And, yeah, they're all software RAID. Also, there isn't much to be
> gained from making RAID0/1 hardware. The software overhead isn't that
> big. For RAID5, having XOR done in hardware helps.
>
Thanks - I suspected that Raid 0 didn't gain anything in hardware unless
they provided additional buffering or something but I just thought I'd
ask in case there was something I was overlooking.
Tejun Heo <[email protected]> wrote:
> And, yeah, they're all software RAID. Also, there isn't much to be
> gained from making RAID0/1 hardware. The software overhead isn't that
The CPU cycles in fact don't usually matter. The I/O overhead (on the
PCI bus) due to multiple transfers of the (more or less) same data is
typically more interesting.
regards
Mario
--
The secret that the NSA could read the Iranian secrets was more
important than any specific Iranian secrets that the NSA could
read. -- Bruce Schneier
Marc Perkel wrote:
>
>
> Tejun Heo wrote:
>> Andre Tomt wrote:
>>> Marc Perkel wrote:
>>>> Running Linux on an AMD AM2 nVidia chip ser that supports Raid 0
>>>> striping on the motherboard. Just wondering if hardware raid (SATA2)
>>
>> SATA2 has nothing to do with hardware RAID.
>>
>>>> is going to be faster that software raid and why?
>>>
>>> Beeing a consumer type board (AM2), the "raid on the motherboard" is
>>> in 99.999% of the cases just software raid implemented in their
>>> Windows drivers, a bootup setup screen plus some BIOS magic to get
>>> the OS booting.
>>
>> And, yeah, they're all software RAID. Also, there isn't much to be
>> gained from making RAID0/1 hardware. The software overhead isn't that
>> big. For RAID5, having XOR done in hardware helps.
>>
>
> Thanks - I suspected that Raid 0 didn't gain anything in hardware unless
> they provided additional buffering or something but I just thought I'd
> ask in case there was something I was overlooking.
A hardware raid controller can buy you a battery backed write cache, so
there are potentially some performance/safety benefits potentially.
We have a mix of software raid and 3ware based hardware raid subsystems.
For the applications we support, in general I can say that performance
was not the discriminating reason to choose one over the other.
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