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Thread: hard drives

  1. Adding the SCSI drive

    I assume that when you are adding a SCSI drive you are pulling the power off of the optical drive for the ATI Radeon 9800 pro and for the SCSI drive.

    Tyler
    Tyler Roach
    Eclipse Creativity, Inc.

  2. #22
    Quote Originally Posted by tylerr
    I assume that when you are adding a SCSI drive you are pulling the power off of the optical drive for the ATI Radeon 9800 pro and for the SCSI drive.

    Tyler
    yes.

    ---

    The g5 jam came with a really poor set of power jumpers that hadnt been crimped very well.
    ---

    in my experience - i have older macs with 4 or 5 internal drives- running power jumpers was not a problem - the psu used always seemed capable.
    I often have a full set of pci cards as well.

    This is not to say this will always be the case.
    I tend to leave things on 24/7 the whole time - often with stuff running to soak test hardware.

  3. #23
    Quote Originally Posted by samsc
    Which Application?

    What kindof tests did you do?
    I did use Xbench 1.1.3..

  4. #24
    Quote Originally Posted by Jan Opseth
    I did use Xbench 1.1.3..
    catalyst is not a datarate limited application - its a seek rate, and rotational latency limited application and io/ops/second limited

    The headline datarate is not relevant.

    Whats important is how fast the drive works- up to a point, and then no more.

    In my testing, 2 drives was not better than one - playing back 4 movies on 4 layers at 25fps. A single drive was better.


    Catalyst is not a normal application wrt disc use. Its quite different.

  5. #25
    Tyler,

    You might need to find yourself a power cable Y-splitter. I misappropriated one from some dead PC kit.

    Hugh

  6. #26
    I have been using 4 Raptors in a Apple 0stripe set for 6 months now and it has worked flawless on my machine. I am able to play 720p HD compressed to half at full speed accross 3 layers (2 at full speed and 1 jumping around from 15 to 30). I am also able to play one layer of 1080p PhotoJpeg compresses to half.

    I have no heat problems with my personal test setup. Unfortunately, it is a bit jury rigged but here are the details. I have 2 drives in the apple and seritek 1s2 card that connects 2 2 30" unshielded SATA Cables to 2 more drives set in their own Metal Gear cases fashioned to accept SATA input. I Chose the Metal Gear external Harddrive boxes because they are for the most part, open, allowing the drives heat sinks to do their job.

    I have used other hardware such as the SATA maxi system that would crash the system running HD after only 20 min. I have also tested the system using different external cases which were fine also in an air conditioned room.

    The trick is not to disturb the G5 airflow at all. By opening up a PCI slot and leaving it open, you will drastically disturb the airflow. I fashioned a PCI cover with a little wedge shaved out of it for the SATA cables to fit out of. This works well.

    I hasten to add though, The Attotech UL4d and a Huge systems Dual channel U320 or any dual U320 drive system will give you data transfer up to 500mb/s, depending on how full the drives are, for over $5,000 - an investment I would consider to make for multiple High Def layers and storage. With 4 Raptors, you can get speeds over 200 mb/s for $1200.00 including cases but you will only get 288gb of data after the format and os and have to deal with SATA cables.

    You can still get speeds over 200mb/s with standard 7200 rpm SATA or ata drives if they are properly striped and partitioned so that only the prime area of each disk is accessable. This is the area of each disk minus all of the inner tracks and part of the outer tracks. You can then turn these drives into 1 large SCSI drive with the right case and hardware. This is what Huge Systems, Promaxx, and a myriad of other high end storage manufacturers do. They don't use a bunch of scsi disks in those cases, they are mostly ata converted to scsi using hardware and software.

    The ATTO UL4D (the scsi interface card you use to hook your mac to your SCSI drives) is suprisingly faster and better than the UL3d. Most people think that the difference is only marginal but the difference is nearly 3 times better perfomance as per my disscussions with Attotech and Huge Systems at NAB.

    After seeing and evaluating all of the options, I've concluded that the best way to go, considering the fact that technology is advancing so rapidly and that there is a new technology called Xsan that will drastically change your appoach to high speed data storage, I would personally would go with the *buy the biggest and best* mentality, because with my needs, I will soon require it. If you aren't pushing the limits of the system or don't see yourself using HD in the near future, you can still benefit from Xsan and a huge fast SCSI system.

    For a cheap "need it now" high speed solution, just get the raptors. They are cheap ($240) and don't require a G5Jam if you don't want one. 4 of them make a huge difference over 2, but again, if you are only running DV content which is a horribly compressed, discolored codec, then it's not worth sweating.

    Each scenario has thier own requirements and pitfalls.

    Christian Choi

  7. #27
    It's a pity you couldn't have made it to the Drive Workshop in London.
    We looked at all the available drive technologies and their pros and cons.

    Raptors have potential but they're not quite fast enough... They're certainly a big improvement on the standard drive, but don't give the performance of a 10,000 rpm SCSI drive.

    Catalyst relies on how many transactions/second a drive can perform and SCSI drives tend to beat all other comers in this department. Even RAID arraying them doesn't improve the performance for our purposes - although this is helpful for uncompressed video sources. RAID arrays increase the possible data rate and overall storage capacity not the transactions/per second - i.e. how quick the drive can physically pull the movie off the drive.

    A 150 Gb 10K SCSI drive is about 400 quid (probably the same in dollars) and a SCSI card is about 200 quid. Perfect. And you can run 1 Ph-Jpeg 50% 1080P movie, two 720P movies and 4 streams of DV PAL effortlessly. DV PAL is not quite as fast as NTSC to decode...

    Hugh

  8. #28
    Yes, I would have liked to come but NAB was beckoning. I agree, you cannot beat SCSI performance. The price here is coming down, the attotech UL4d is around 550 USD and a 74 gig 10k drive around 250.

    Did you guys try any 8 drive arrays or an Xserve raid storage system with Fiber Channel? I'd be quite interested in how the Xserve storage system would work with Catalyst.

    Best,
    Christian Choi

  9. #29
    What did you need to do to get optimum speed from your UL4d? I just added a UL4d and a Atlas IV 10K and am not seeing the improvment I was expecting. It is in the 133 slot, however it did not seem to come with any special software. Is it really PnP at 133mhz?

    Thanks
    Chris

  10. #30
    Multiple U320 drives in a zero striped set down 2 channels. A good example would be 2 drives on one channel and the other 2 on another, or more. Use AppleRaid (disk utility) to build a 0 striped set.

    With a single drive you aren't going to see much difference, at least you have the foundation to add more drives as you get them, they all must be the same capacity or they will get truncated to the lowest capacity drive.

    A single drive won't do much more than a single SATA drive.

    Christian

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