RAID0 with SilImage or nForce4

[keitaro]

For a while I've not thought about this much. But now that I have, I've been constantly trying to search for the answers. I've found bits and pieces that can potentially answer what I am about to do and inquire but nothing direct. So ...

I've a pair of WD 250GB (WD2500KS-00MJB0) drives. They are SATA-2 capable but I highly doubt it has NCQ anyway. They're currently connected to the Silicon Image 3132 controller in RAID-0 (64k striping).

Now, the question is... Is it possible to switch to the nForce4 RAID controller without the need to do anything that can potentially wipe the drive of any data on it? I've been lazy on backing up stuff on the RAID0 disk and things are backlogged up the wazoo.

Another question is... "Disabled tagged queuing" and "Disable synchronous transfers" checkboxes on the "SCSI Properties" tab on the disk's Properties. Do I want to tick these? A lot of search results involved Raptor drives and I only wanted to make sure that it's applicable to others.

And the final question... Which would net me better performance overall? The SilImage controller or the nForce4? I recall something about data corruption regarding an nForce chipset and RAID but I cannot seem to find out which version and whether or not if the issue was resolved or worked around.

The system spec is at the sig if you needed info and yes the system is overclocked modestly from 2.0GHz to 2.4GHz. If you require more information, lemme know and I'll try to post it here.

[joern]

[LostBok]

I'm not sure if this is contratry to Joern's experience or just to clarify: it's not possible to ghost (move) a RAID0 array on one controller to any sort of array on any other controller unless you have different physical discs, OR you have an intermediate storage (borrowed hard drive / DVD's) to store the data on.

I've migrated my OS from one controller to another numerous times... on my current nForce4, on my dual Xeon HTPC, my Intel P4 file server and also going back as far as my Pentium166 with it's Promise IDE RAID controllers. I must say that usually I have been doing this because I have a new RAID card with bigger / faster disks or I wanted to switch from RAID0 to RAID5.

Just recently, I took my slightly risky file server with 2 x 500Gb discs in RAID0 and migrated it to a 3 x 500Gb RAID3 array on a separate controller card - via n external 2Tb Firewire800 drive.

The key to it is having a spare disk to migrate to: see *V* below.

One caveat I'll put on this, is I have NEVER been able to migrate Vista seamlessly. You have to rerun the install DVD and select "repair boot drive" on the new image once you have migrated it.

NT4, win2000 and winXP will need some tweaking with the boot.ini file if you want both the source and target to be bootable (i.e. you want a "work" boot and a "play" boot).

By the sounds of things, you're just looking to migrate so this is what you need to do:

*V*

OPTION ONE: Source and Target array will use the same hard drives.

Preferably procure / borrow a hard drive that will be big enough to hold the data from the source drive. I usually find it better if you can migrate or archive most of the "data" (media files, pictures, etc) - there is some risk, so make sure all precious photos and docs are backed up anyway! This process can be done to DVD, but 500Gb = 120 DVD's and a LOT slower!

Make sure that the current OS isntallation has the drivers required for the other RAID controller. If possible, test this by putting ANY old hard drive on the other controller and setting up ANY sort of array (even JBOD).

Use something like Norton Ghost (I think it's called Symantec Ghost now), I think there are a few other products out there, but Ghost is by far the most reliable!

Ghost the entire source disk to another hard drive (external USB / firewire or IDE / SATA - anything!). This can either be done as a series of image files or an exact copy (very entertaining to be able to boot your PC off an external USB ). I have done this to DVD once before, but it's pretty tedious if it's much mroe than 12Gb of data (3 x DVD's).

You then need to delete the RAID0 array in the controller's BIOS, physically plug the drives into the new controller and then recreate the new array in the new controller's BIOS.

Ghost back from your temporary storage or DVD's onto the new array and CHANGE THE PC's BOOT ORDER and put the new RAID controller in the same place as

If you don't do this, the PC will try to boot off "HDD0" on the old controller.

OPTION 2: You have a new hard drive array that you want to upgrade to.

Create the new array on the new BIOS.

The new array has to be big enough to host all the data on the source array - note they do NOT have to be the same same - only that the data should fit.

Ghost the source across to the target and chagne the BIOS to reflect the new boot order.

[LostBok]

Which is faster: these results may have been superceded with later BIOS/driver updates or may vary from one typeof HDD to another, or indeed with different CPU's!

This, if I remember correctly this was with an A64-3500+ overclocked to 2.5Ghz and two Raptor 74Gb 10,000rpm drives.

Onboard SIL3114:


Onboard nV RAID:


And together:


Sustained throughput approximately the same, but lower CPU usage on the 3114 won it for me.... plus left me more options wrt to SATA optical drives.

[joern]

@LostBok

Interesting to see your measurement results. I don't know what the reason is that both controllers operate at about the same speed.
The nForce4 should be faster though. Maybe it depends on the RAID level. You tested with RAID0.
A RAID1 or 10 would be interesting to compare, too.

Maybe it's the HDD themselves which limit performance?

OR: Maybe just no one checked the performances before and found out that these controllers are always equally fast, contrary to theoretical considerations by mainboard chip and bus concepts.

Anyway, thanks for your detailed analysis!
Pat

[LostBok]

I doubt that 74Gb Raptor's would have been the limiting factor - I'm 100% sure I was testing those two... it was how far I'd OC'd the CPU that I was unsure about, but that 3500+ was running at 2.5Ghz most of the time.

I'm pretty sure that I did test the drives as a RAID mirror too: I was running my OS off an old IDE drive, so I was chopping the drives config back and forth from one controller to another as single drives, striped and mirrored. I wasn't that interested in the miror as I was going for outright speed for just the OS and games - even my MyDocs was kept on another drive and I would ghost the OS every few weeks. Sorry - I can;t find the benchmarks screen grabs, but I'm pretty sure the CPU usage cap was even bigger and the burst speed gap was even smaller - despite what the theory suggests.

I agree that the PCI-E device should theoretically be faster - this is partly backed up with regards to the much higher burst speed and the SIL3114 is a slightly more advanced RAID chip (as far as I understand), so that would explain the lower CPU % i.e. the SIL3114 does more of the work.

You might find that those older drivers (note 2005 test date) didn't allow the nF RAID controller to work to it's full potential, so not sure how relevant these tests are still.

Either way it no longer has any impact on me as I've got rid of the Raptors and I'm now running SCSI RAID5 for my OS (also with 10,000rpm drives) and the SIL3114 just has 3 x 320Gb's in RAID5 for misc data storage - I've kep my nF SATA channels clear for my DVDRW drives.... all my media is on a file server (1Tb RAID3 with 1Gbps LAN) and the more precious data is on a 500Gb RAID1 NAS box also 1Gbps in theory, but more like 100Mbps in practice.

If I get hold of another pair of fast HDD's, I'll give them another try (perhaps incl RAID 5 this time, if I can get three or 4 of them), but not sure who's gonna donate that sort of hardware - especially not the Raptors