Which onboard raid controller?

paul_31 · 6 Aug 2009 at 11:34

I will be putting a Gigabyte GA-MA790XT-UD4P in a new build and to start off was planning on having 2x500GB drives in Raid 0 (backing up manually to external). The mobo supports raid on both the Southbridge and also a dedicated SATA2 chip -

South Bridge:

6 x SATA 3Gb/s connectors supporting up to 6 SATA 3Gb/s devices
Support for SATA RAID 0, RAID 1, RAID5, RAID 10 and JBOD

GIGABYTE SATA2 chip:

2 x SATA 3Gb/s connectors (GSATA2_0, GSATA2_1) supporting up to 2 SATA 3Gb/s devices
Support for SATA RAID 0, RAID 1 and JBOD

It seems a silly question but would I see any differences between these controllers in a raid0 setup? Which would you suggest using?

Thanks,
Paul.

adamscybot · 6 Aug 2009 at 12:34

paul_31 said:
I will be putting a Gigabyte GA-MA790XT-UD4P in a new build and to start off was planning on having 2x500GB drives in Raid 0 (backing up manually to external). The mobo supports raid on both the Southbridge and also a dedicated SATA2 chip -

It seems a silly question but would I see any differences between these controllers in a raid0 setup? Which would you suggest using?

Thanks,
Paul.

Yes theres a difference, the gigabyte ones are slower - they use a rebranded JMicron controller.

The Intel sata controller is faster in benchmarks.

jbloggs · 6 Aug 2009 at 12:43

Use the South Bridge (AMD SB750) (also see Here) not Gigabyte SATA2 which as already stated is poor to say the least...

paul_31 · 6 Aug 2009 at 13:21

Thanks guys, using the Southbridge also gives me the option of going for raid 5 if I add another drive. Is it possible to migrate from Raid 0 to Raid 5 or is it better to do a clean rebuild with Raid 5 from scratch?

jbloggs · 6 Aug 2009 at 16:41

Generally (if I remember correctly), you don't put the OS on a RAID5 volume, but on a separate volume, which could be another (single) HDD or for maximum effect (from failure) a RAID1 volume, so that would mean doing a clean install of your OS, then after that building a RAID5 volume. Do be aware that a RAID5 volume on an onboard (software implemented) controller will have poor "write" values...

Ch3m1c4L · 7 Aug 2009 at 14:01

your os can be on a raid 5 volume, as long as its under 2TB and you set it as bootable on the controller.

Poor write values....mine arent THAT poor, the lowest ive seen was 50mb on one test but i must have been doing something else at that point since normally its around 60-70 i think. Thats writing from one HDD to my array.

jbloggs · 7 Aug 2009 at 21:54

Poor write values....mine arent THAT poor...

I am assuming that you have 5 x 1TB F1s in RAID5 on your onboard (software implemented) controller and you reckon 60-70MB/s is not poor, however if you put them onto a true hardware SATA RAID card (with onboard processor + ram) you would be getting considerably higher write values due to it's processor doing the parity calculations...and this is what was behind my comments in my last post regarding poor write values when using onboard controller of motherbaord...

your os can be on a raid 5 volume

Yes, you certainly can do this, however it does not appear to be normal convention when using RAID 5 and looking for lowest risk of possible failures of volumes to safeguard data...

WJA96 · 8 Aug 2009 at 06:43

jbloggs said:
I am assuming that you have 5 x 1TB F1s in RAID5 on your onboard (software implemented) controller and you reckon 60-70MB/s is not poor, however if you put them onto a true hardware SATA RAID card (with onboard processor + ram) you would be getting considerably higher write values due to it's processor doing the parity calculations...and this is what was behind my comments in my last post regarding poor write values when using onboard controller of motherbaord...

RAID 5 is very slow indeed. It's by far the slowest of all the RAID types. That's because it's doing loads of calculations and working out where to split data across all the drives in the array.

jbloggs said:
Yes, you certainly can do this, however it does not appear to be normal convention when using RAID 5 and looking for lowest risk of possible failures of volumes to safeguard data...

Indeed, however your original post could be misinterpreted that you shouldn't or couldn't do it, when it reality, it's fine. I personally have RAID10 for my boot drive set and RAID5 for my data sets. Dell PERC controllers

jbloggs · 8 Aug 2009 at 11:33

RAID 5 is very slow indeed. It's by far the slowest of all the RAID types. That's because it's doing loads of calculations and working out where to split data across all the drives in the array.

The point I was making was that write values when using an onboard (software implementation) controller will be lower because of this very fact of the necessity of the parity calculation that have to be made being made by the CPU rather than by the onboard processor on a true hardware SATA RAID card which removes this limitation on write values...

i.e., the write values for 5 x 1TB F1s will be higher when using a Dell Perc 5/i (if setup properly) than when using an onboard (software implementation) controller like the OP is...(see Here for (RAID5) "write" benches for Perc 5/i)