Tell me about your XGrid.

Discussion in 'Mac Pro' started by Sesshi, Dec 12, 2006.

  1. Sesshi macrumors G3

    Sesshi

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    #1
    What do you do with an XGrid setup? Details of your setup? Any regrets or what you would have done differently?
     
  2. cynerjist macrumors regular

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    #2
    I would love to hear some details on this, too. Anyone?

    Are we all too poor to have an Xgrid?
     
  3. trainguy77 macrumors 68040

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    #3
    Well I was going to start using xgrid for compiling. However, it turns out that a intel machine can not distribute to ppc and ppc can't send stuff to intel. This was some what annoying. So I don't use xgrid.
     
  4. robbieduncan Moderator emeritus

    robbieduncan

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    #4
    What? Even if your building a Universal Binary? That sucks.
     
  5. Sesshi thread starter macrumors G3

    Sesshi

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    #5
    Really? That's a bit of a shame. Any idea when that will be sorted out (even if they can't get it to work mixed)?
     
  6. Jasonbot macrumors 68020

    Jasonbot

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    #6
    Is it possible to XGrid any two macs or do they have to be super 1337 Mac Pros?

    And then on another note: Could this be ussed to inrease gaming performance under OS X? Or is it just for appl enative apps like iLife and Xcode?
     
  7. robbieduncan Moderator emeritus

    robbieduncan

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    #7
    Yes. Any Mac running a fairly recent version of OSX can participate in an XGrid.

    No. It's nothing to do with an app coming from Apple though. Apps have to be specially coded for XGrid. The distributed compiling in XCode does not actually use XGrid either. There are no consumer level apps that I know of that can use XGrid. iLife certainly can't.

    Games are about the worst possible situation when it comes to technology like XGrid. XGrid is good for problems where you can parcel a part of the problem up and send it off for work and get the result some time later. The computational cost must be high enough that the network latency does not matter. Real time or interactive response is the exact opposite. Latency is the worst thing possible here.
     
  8. Sesshi thread starter macrumors G3

    Sesshi

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    #8
    No. The XGrid doesn't simply turn the grid into an XGhz single Mac. It's mainly for the likes of scientific computing and distributed graphic rendering, etc. There's no usual use for it for the 'regular joe'... but there are conceivable uses for the power non-professional user (which would have to be coded for), such as transcoding Apple Lossless audio to regular compressed AAC/MP3 quickly for transfer to iPod in as near real time as possible by splitting out the transcoding job to many machines.

    And it would help if they were super 1337 Macs.
     
  9. Jasonbot macrumors 68020

    Jasonbot

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    #9
    Damn! But then I can do it when encoding video's via quicktime? Or how about iMovie effects?
     
  10. robbieduncan Moderator emeritus

    robbieduncan

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    #10
    Not unless you have an insanely fast network. The cost of sending the frames of video over then network would be likely to outweigh the computational benefit. Which is probably why Apple have not implemented this. The traditional applications for this are things like scientific apps where you can send a couple of megabytes to each machine which then spends 10 minutes working to send back the results.

    The other thing you have to remember is that each individual unit of work can't be dependant on the previous or following units unless those completed units are also sent to the machine. So if you want to compress frame 100 to H.264 you also need the results of the compression to this point.

    The compiling stuff works as each file in the source code is compiled to assembler which is then all linked together. The files are independent so you can send each off to a machine and wait for the results.
     
  11. Jasonbot macrumors 68020

    Jasonbot

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    #11
    Well thanks for all the info guys, But one final input: would gigabit ethernet be a good workaround for the latency issue? Or is that just my crazy mind working in overdrive?

    Luckily I finally understand the pros and pros of Xgrid and it's implications in real world situations.
     
  12. robbieduncan Moderator emeritus

    robbieduncan

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    #12
    Gigabit helps but nothing is going to stop the issue that you need specially written apps to take advantage of this and even with gigabit how long would it take to transfer a chunk of video (say between two reference sync frames) to each client? Having transferred all that how long to transfer it all back and re-assemble? Probably longer than it would take a fast machine to encode it itself! And for gaming and any other form of interactive use all forms of ethernet have too much latency (network speed and latency are totally different things) to work.
     
  13. Jasonbot macrumors 68020

    Jasonbot

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    #13
    My dreams of networked computing have been shattered *burst out in howls of pain* Anyways, thanks robbieduncan for all the input. I will now continue ripping movies at slooooowwww rates on my Core 2 Duo iMac :mad:
     
  14. robbieduncan Moderator emeritus

    robbieduncan

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    #14
    Never say never. There are clever people than me out there and they may end up solving this. More likely you will buy a new machine in 2 years time that's 4 times (or at least has 4 times as many cores) as the one you have now!
     
  15. trainguy77 macrumors 68040

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    #15
    I don't think apple will ever take the time to fix that problem. Annoying but o well.....:(
     

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