MacPro + SSD + iDVD?

Discussion in 'Mac Pro' started by LeicaM8, Nov 30, 2012.

  1. macrumors member

    LeicaM8

    Joined:
    Nov 29, 2012
    Location:
    West Michigan
    #1
    Hi All, I Am very happy with my MacPro Mid-2010 12gig 4 core 2.8GHz in just about every way except one: iDVD Encodes. I know, old and EOL, but I have a need to produce some discs once a week and it's the app I have.

    Since iDVD is hard capped by a maximum of using 2 Cores I am left without a way to address that bottleneck, but it occurs to me I can address how fast data gets into those two cores.

    Query: How much improvement might I see in my iDVD encodes by going to an SSD Boot Drive with my source & destination files on it?

    Time reduction of a few percent? 10% - 25% - 50%?

    Knocking even say 25% off a 3hr encode is signifigant enough to be worth my effort in my opinion.

    Sincerely
    Richard in Michigan
     
  2. macrumors 6502a

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    #2
    Seems to me you're governed by your DVD drive
     
  3. thread starter macrumors member

    LeicaM8

    Joined:
    Nov 29, 2012
    Location:
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    #3
    Thanks for Responding, sincerely.
    If you are referring to DVD Burning, your comment is spot on!
    However I'm coping with an excessively long DVD Encoding problem which is an entirely different challenge where the chief bottlenecks are CPU Usage and the movement of data to & from a hard drive.

    Unless I am utterly misinformed!
    (Not Un-Precedented in my Life)

    BTW I have iDVD create a disc image rather than burn the disc because Toast writes faster/better imo and if there is a mis-burn it's instantaneous to try again.

    Richard in Michigan
     
  4. macrumors 6502a

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    #4
    Could handbrake achieve the same result for you with better processor usage?
     
  5. ColdCase, Dec 1, 2012
    Last edited: Dec 1, 2012

    macrumors 68020

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    #5
    If the CPU is not the significant bottleneck, then using two drives, one for source video and one for the destination encoded TS files, could be better than one fast drive for both. Of course two fast drives would be better.

    I've done this as routine for several years now (perhaps its an old wives tale) so I don't know what % gain you would get. Its certainly more than 0, however.
     
  6. thread starter macrumors member

    LeicaM8

    Joined:
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    #6
    Good thoughts.
    I did switch to using different drives a few months back and there was an improvement, but the speedup wasn't especially noteworthy.
    My girlfriend is working hard to talk me into stopping with the 'due diligence' dithering and just buy a good SSD and find out.
    R. In Mi.
     
  7. thread starter macrumors member

    LeicaM8

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    #7
    I've been trying for many months to find a way to do that very thing, but no Ah Hah Moment as of yet. The iDVD projects are made from everything from vhs digitizings to hd source files and shrinking the HD with Handbrake down to dvd resolution has helped. Though, only in keeping high res files from doubling the encode times.

    R in Mi
     
  8. macrumors regular

    Joined:
    Mar 10, 2010
    #8
    Listen to the girl! She's obviously the brains of this operation ;-).
     
  9. thread starter macrumors member

    LeicaM8

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    #9
    You have no idea how true that statement is!
    #
     
  10. macrumors 6502a

    tyr2

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    Location:
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    #10
    You can check yourself where your bottleneck it. I'd expect it's the CPU power and not the disk speed at all.

    Run 'Activity Monitor' while performing some encodes. Keep an eye on the CPU tab, if it's running at 100% maxed out on a number of cores than adding faster disks isn't going to make any difference to that phase.

    If it's failing to max out the cores or if there is a later phase of the encode where it copies the data about for some reason you should see that on the 'Disk Activity' tab. If my Mac Pro (1,1) I get 250MB/s max write to a SSD and 95MB/s to a regular HD. If the process isn't already hitting numbers in those ballparks then putting faster disks in probably won't make much difference.
     
  11. thread starter macrumors member

    LeicaM8

    Joined:
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    Location:
    West Michigan
    #11
    Thx for the input.
    The Stats you suggested to check are:
    iDVD CPU usage is 150% on avg
    - this is on a 2.8ghz quad-core intel xeon
    - notably to me, a single core does NOT get saturated during the encode process, usage is distributed across all cores.
    Hard Drive read/write numbers are:
    750k/sec sporadic reads and sporadic writes at 250k/sec

    Based on your info it would seem that I am having feeble Read/Write Performance issues that would DEFINITELY benefit from installing an SSD. Would you agree with my thinking on this point?

    Based on my rough knowledge of multi-core processing on my mac, if the task is not saturating a single core then there exists the potential to speed up a task. BUT this might be irrelevant for iDVD as I am informed it is written so that it is capped to use 2 cores.

    Sincerely,
    Richard in Michigan
     
  12. macrumors 6502a

    tyr2

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    #12
    Actually no I would suggest that the numbers point to the drive being perfectly fine as it is. Those numbers are nowhere near the max capacity of the drive. The reason you're not seeing higher numbers is that iDVD isn't wanting the data any faster. Adding SSD might make a small difference but I bet you'd hardly notice.

    If you're seeing 150% CPU usage on average then that's approx 1.5 cores. In the CPU tab at the bottom of Activity Monitor there is a small graph showing usage per core. Sounds like you've got 2 cores that are pretty busy already. If iDVD can't scale to more cores, then adding a faster drive won't help, you'll still be stuck with the CPU performance.

    I'd suggest you stick with what you have.
     
  13. thread starter macrumors member

    LeicaM8

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    #13
    Your info sounds quite reasonable.
    I do have a general question though.
    Wouldn't an app limited in it's design to use two cores, like iDVD, have it's processing occupy two cores while the other 6 shown in Activity Monitor remain nearly idle?
    Some of the tasks in iDVD do exactly that - saturate one core. (I believe that is the menu rendering) However during the encoding process all 8 cores are handling a distributed load across all eight cores.
    Does this observation reflect something the OS/CPU Controllers do in response to only being asked to use 2 cores?
    eg:distributing the task so the load is leveled across the available cpus?

    Thanks for the help!
    Richard in Michigan
     
  14. LeicaM8, Dec 3, 2012
    Last edited: Dec 3, 2012

    thread starter macrumors member

    LeicaM8

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    #14
    Not sure if would be helpful, but here is a screen capture of my CPU History window showing the way the cpu load is being distributed across all 8 cores.
    (Set to standard 2 second update intervals)
     

    Attached Files:

  15. macrumors 6502a

    tyr2

    Joined:
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    Location:
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    #15
    Sounds like different parts of iDVD are multithreaded differently. From what you have observed it sounds doubtful that iDVD was specifically forced to a 2 core maximum, otherwise you would only see threads on 2 cores. However given it's age it was probably only designed with 2 cores in mind. As such it is creating multiple threads over multiple cores to do the rendering, just not all the effectively.

    It seems a little weird that during the rendering phase you have threads running that aren't taking up the entirety of the CPU resource available to them. It's just a guess but I would suggest that whatever the thread is in iDVD that is controlling them is the bottleneck, it is possibly feeding the data into and out of the rendering threads and not itself scaling over multiple cores. It was probably not designed for feeding data to so many rendering threads at the same time.

    As I say it's just a guess, but it's my hunch as to what is happening.

    If you fancy trying an experiment and have enough RAM available you could create a RAM disk using http://tmpdisk.inkscribbles.com and put a small iDVD project and rendering destination on there. That'd be the fastest storage you'd ever get. Would be interesting to see if it made any difference to the rendering times.

    (BTW I have not tried tmpDisk myself, it was just something I came across looking for a RAM disk for OS X).
     
  16. macrumors 6502a

    tyr2

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    #16
    With reference to that screenshot it looks like it would well utilise a quad core CPU, quad core pro's were pretty common back when iDVD was last refreshed.

    I guess your CPU has hyper threading hence seeing 8 cores? I'm not sure how well iDVD would be optimised to cope with such a configuration. At the end of the day you still only have 4 execution cores to work with.

    Personally I don't think that utilisation is too bad for an application of it's age.
     
  17. thread starter macrumors member

    LeicaM8

    Joined:
    Nov 29, 2012
    Location:
    West Michigan
    #17
    You make excellent suggestion and your hypothesizing seems sound.
    I honestly thought OS based Ram Disks went way of the Do-Do when OS9 went bye-bye. Just this Saturday I was lamenting I didn't have that option! Since I have over 7 gigs of unused Ram Space, I suspect a Ram Disk App is an experiment I can easily run. Probably would tell me if an SSD would be at all beneficial.
    Thx.
    Richard in Michigan
     

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