Striping internal drives on a Mac G4 dual 125
by John
on
Mar 1, 2005 at 3:01:18 pm
Good day,
I am having a problem with FCP 4.5 and my Aja IOla, I think? FCP quits when I get effects heavy in parts of my sequence and I have had it at the Apple store too many times. They seem to think it is the drives, and if it is, do I need new drives? Or do I need to stripe the raid with a different program than just the Apple drive utility? The 2 drives in question are Western Digital 180 gigs.
Re: Striping internal drives on a Mac G4 dual 125 by Ed on Mar 1, 2005 at 3:49:46 pm
The Disk Utility striping utility should be fine. I have the same setup (IOLA and G4 MDD 1.25). I don't think a 2 drive array is fast enough for FCP work, unless you're only doing DV work (I'm guessing no, since you have the IOLA). Get a 3rd (or even 2 more drives). And make sure they're exactly the same as the 2 existing drives. Another option (and the one we used), is to put 4 drives in the G4, all striped together, and using a FireWire drive as the boot drive. We even got a 2 drive FW case, so we have yet another drive for backing projects up.
Ed
Re: Striping internal drives on a Mac G4 dual 125 by Tom Volotta on Mar 4, 2005 at 6:35:37 pm
Assuming your configuration has the internal boot drive on the ATA 100 bus, the two 180GB WDs (8MB cache?) are then sharing the ATA 66 bus in a Master-Slave relationship for the RAID0. This is not a proper RAID0 since the read/write between the drives is sequential, not simultaneous. Each drive in the RAID should be a Master, on it's own discrete channel.
As mentioned, it is possible to do the external FW boot, with four internal drives hooked up as a RAID, but if configured as one big RAID, it will run at the slowest bus speed, 66, and is still a Master-Slave relationship. The boot drive can also be kept internal, installed lower optical bay, but this is only an ATA 33 bus. It does work, although not the greatest way to go.
A superior solution would be installing a PCI RAID controller card. A very good performer is the Acard 6885M, which allows 4 independent channels (2 or 3 channels also possible with this card). Acard has a specific configuration (on the 4-channel) where one of the RAID drives is installed in the upper optical bay, thereby permitting the internal boot drive to run off the ATA 100 bus. I've run this 4-channel set-up for some time in a G4 DP 1.25 MDD, AJA Io, typically working with 10-bit UC, and it's been just fine.
Re: Striping internal drives on a Mac G4 dual 125 by Ed on Mar 4, 2005 at 8:38:34 pm
[Tom Volotta] 1) "Assuming your configuration has the internal boot drive on the ATA 100 bus, the two 180GB WDs (8MB cache?) are then sharing the ATA 66 bus in a Master-Slave relationship for the RAID0. This is not a proper RAID0 since the read/write between the drives is sequential, not simultaneous. Each drive in the RAID should be a Master, on it's own discrete channel.
While it's true that the drives are put in a master/slave position, it's also true that you get a substantial speed increase by striping drives across the ATA 100 buss, and you get another speed increase (although not as substantial) when you add 2 more drives across those 2 channels (as well as more storage, of course). I posted this, along with a FW array speed test a while ago, here's just the 4 ATA internal RAID0 drive test (with drives 90% full):
Sequential Read 81.43
Sequential Write 75.13
Random Read 98.79
Random Write 85.58
100MB Extended Read 77.12
100MB Extended Write 122.31
2) As mentioned, it is possible to do the external FW boot, with four internal drives hooked up as a RAID, but if configured as one big RAID, it will run at the slowest bus speed, 66, and is still a Master-Slave relationship. The boot drive can also be kept internal, installed lower optical bay, but this is only an ATA 33 bus. It does work, although not the greatest way to go.
This setup was recommended be a number of vendors, including the late Charles NcConathy at Promax, and as you can see by the numbers, is fine for uncompressed 8bit or DV work.
3) A superior solution would be installing a PCI RAID controller card. A very good performer is the Acard 6885M, which allows 4 independent channels (2 or 3 channels also possible with this card). Acard has a specific configuration (on the 4-channel) where one of the RAID drives is installed in the upper optical bay, thereby permitting the internal boot drive to run off the ATA 100 bus. I've run this 4-channel set-up for some time in a G4 DP 1.25 MDD, AJA Io, typically working with 10-bit UC, and it's been just fine. "
I wouldn't even think of this last solution, because if I was going to spend money on a PCI card, it would be a SATA card, which could also be installed internally, and have much better performance than any ATA setup.
Ed
Re: Striping internal drives on a Mac G4 dual 125 by Tom Volotta on Mar 6, 2005 at 8:21:53 pm
Ed,
Sure, SATA is better. Adding PATA/SATA adaptors to interface those drives with a SATA RAID controller is a good approach, as would be a PCI FW 800 card/drive RAID setup.
My suggestion was simply a solution I've had direct experience with regarding John's original question concerning his G4 DP 1.25 MDD using existing WD ATA drives.
I did run the Master/Slave soft RAID (including the 4-drive RAID with boot drive in the ATA 33 optical bay) long ago, but didn't find that configuration reliable for working with 10-bit UC, which is why the 4-channel Acard was a good way to go a few years back. It's been very solid.
John, costs and other considerations come into play in getting more life out of an old (but perfectly useful) system. Lots of comparison info for various RAID configurations on:
