RocketRAID - 8 channel Serial ATA card for Macintosh

Originally posted September 22nd, 2004, by rob-ART morgan, mad scientist
Updated September 24th, 2004 with results from 8 MaXLine IIIs
and some cautions on kernel panics

After a year of waiting, a Macintosh compatible SATA PCI host adapter with more than 2 ports is shipping. We've also been praying for an adapter that's PCI-X rated. Two weeks ago, HighPoint quietly released the Mac drivers for their RocketRAID 1820A 8 channel PCI-X SATA host adapter. It's been shipping for Window PCs for some time. I was able to observe the performance of the card at the ProMax test lab the day the drivers were released to the public. I was impressed, but (as you can imagine) anxious to test it for myself.

TEST 1: DIFFERENT DRIVES COMPARED
This first series of graphs show how 4 serial ATA drives from 3 different manufacturers performed on the RocketRAID. We put them in a RAID 0 set using SoftRAID 3.0.3. We used DiskTester instead of QuickBench this time because it closely mimics the speeds we saw when the BlackMagic Speed Test was run on a DeckLink equipped G5 tower. In other words, you 10 bit HD jockies can take these numbers to the bank.

In the last edition of these graphs, we observed what appeared to be a limit of 343MB/s for write speed. This time, with identical drives, we observed an amazing phenom. The six and seven drive RAID sets posted faster write speeds than the eight drive RAID set at 10% capacity. Very interesting. However, the eight drive set showed its stuff as we approached the capacity of the volume. At 90% capacity, it was "pulling" harder than the six and seven drive sets.

As you can see, six good performing drives exceed the magic 180MB/s desired to process uncompressed 10bit HD video. And such a set exceeds that number even when the RAID volume approaches capacity.

One very nasty thing happened while we were testing the seven drive raid set. Three times in a row while running the 5 GB Disktester read/write test, our G5 had a grey screen kernel panic half way through the test. A few hours later, I read that an HD Video jockey in Texas had a kernel panic while duplicating a 5 GB file. We're still probing the limits of this card. If you plan to use this card for production, we want you to know all the problems we've encountered.

TEST 3: ONE ROCKETRAID VERSUS DUAL SERITEK/1SE2s
A week after the RocketRAID Mac drivers were released, FirmTek launched their dual port SATA host adapters with EXTERNAL ports. (The RocketRAID has only INTERNAL ports.) What if we wanted to set up a 4 drive external SATA RAID box without kludging cables out an empty PCI slot? Would two SeriTek/1SE2 host adapters with external ports connected to 4 external SATA drives in a RAID 0 set be as fast as putting the same 4 SATA drive RAID set on a RocketRAID?

As you can see, the SeriTek solution would be as fast, but there's a downside. It takes up two slots on the G5 Power Mac. And to avoid bus contension, one of them has to be in slot 4 -- which many of you reserve for your DeckLink or Kona capture card. That's why the one card solution is most attractive.

Speed tests are sexy but let's review the features that are present or lacking in the RocketRAID:
FEATURES or advantages
You have room to grow with 8 ports
It captures 10 bit uncompressed HDTV with 4 or more drives in a RAID 0 set.
The included RAIDMan software supports RAID 0, 1, 5, 10 and JBOD.
It's compatible with both SSC and non-SSC drives.
The kit includes 8 SATA internal cables.
It runs on G4 and G5 Power Macs under OS X 10.2 or newer.
It's an affordable solution ($204 at ZipZoomFly)

"NON-FEATURES" or deficiencies
None of the 8 ports were external.
You can't boot your Mac from any drive connected to the RocketRAID.
There's no hot-swap support. You must Shutdown your Mac to connect/disconnect.
It does not support Deep Sleep
It "hits the wall" at 340MB/s WRITE speed, with 5 or more drives in RAID 0 set.
Their RAIDMan utility runs slower than Apple's RAID software and SoftRAID and limits you to 2 terabytes.
It lacks support for G3 Power Macs with PCI slots
There's no support for Macs running OS 8, 9 or 10.1
The plastic connectors break easily. (This can be an issue especially if heavily shielded external use data cables are routed out an empty PCI slot to external SATA boxes.)
The included data cables are rated for internal use only. For external use, you should purchase cables with heavier shielding rated for external use and able to combat electronic interference that can compromise your data transfers.
Exhibits the disconcerting tendency to cause kernel panics under certain conditions.

CONCLUSION
The RocketRAID may not be the perfect SATA RAID solution, but right now it's the only game in town if you want one PCI-X SATA host adapter with more than 2 ports.

I have received email from readers running the RocketRAID who are ecstatic about the results. Others are not so happy. Two have reported various problems. You can read about one user's experience on the Apple Discussion pages. Both users reporting problems had crammed as many as 10 drives inside their G5. Their problems could be power related, since they are pulling power off either the SuperDrive or factory drives -- which may not provide the steady voltage needed.

Although the RocketRAID has only internal ports, I'm beginning to think that it will work best with the drives in an external box like the ones sold by MacGurus and Granite Digital.

HOW WELL DOES THE ROCKETRAID PERFORM ON A G4 POWER MAC?
We tested four MaXLine III drives (RAID 0 config) on a G4/1.42GHz MP Power Mac (64 bit 33MHz PCI slots). The sustained READ speed was about the same as the G5 (200+ MB/s). However, the sustained WRITE speed was an unimpressive 132MB/s (compared to 280+MB/s on the G5). Moral: If your project requires serious storage throughput, then it might be time to buy a G5 Power Mac.

MORE ON WHY YOU MAY WANT A SATA CONTROLLER WITH MORE THAN 2 PORTS
There are good reasons to have more than 2 ports on a your SATA PCI host adapter. If you have G5 Power Mac with a DeckLink or Kona card in slot 4 and want to control a fast SATA array for capturing 10 bit HD video or for Photoshop scratch, then you really need a single SATA host adapter with at least 4 ports. In spite of its "non-features," the RocketRAID is the only shipping Mac compatible SATA host adapter that fulfills that requirement.

Some of you have created a four drive, four channel SATA array using dual FirmTek SeriTek/1S2 cards. But you've also found that if you put them in slot 2 and 3 of your G5, the write speeds go way down. When you put them your G4 tower and span drives across the cards, the speeds go way down. If you are creating a RAID set with more than two drives, you really need a host adapter with more than 2 port/channels. Until someone else offers a four, six, or eight channel Serial ATA PCI-X host adapter, the RocketRAID is the only game in town for extreme Serial ATA RAID 0 sets.

Speaking of extreme, I received an email from a reader who is running eight drives on his RocketRAID and boots from the dual Raptors in the factory slots. Zowee! Mike Curtis filed a report on his website for independent filmakers on his 16 drive array involving the RocketRAID. He has plans for a 16 drive set once he replaces his defective second RocketRAID.

The test "mule" was our trusty G5/2.0GHz MP Power Mac purchased from Small Dog Electronics.

LIST OF OF TEST SOFTWARE
SoftRAID though Apple Disk Utility RAID function is free, there are good reasons to buy SoftRAID.
DiskTester, a non-GUI utility that allows us to simulate large block capture and playback. It also lets us test the whole volume quickly to see how the speed drops off as the volume fills up.
Finder Duplicate (duplicate a 1GB file forcing the volume to read from and write to itself simultaneously)

If you are shopping for SATA drives, controllers, converters, mounting kits, or enclosures, be sure to check pricing and availability at the following websites:

HighPoint RocketRAID PCI-X host adapter: 8 Channels of "raw" Serial ATA power for the Mac

HighPoint RocketRAID PCI-X host adapter:
8 Channels of "raw" Serial ATA power
for the Mac