How is a Quad G5 Slow?

Discussion in 'PowerPC Macs' started by noodle654, Jun 26, 2009.

  1. macrumors 68020

    noodle654

    Joined:
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    Location:
    Never Ender
    #1
    I never fully understood this topic really. I have always been interested in getting a G5, ever since they came out. I might be able to nag a Quad G5 for very cheap, but I have a question. I know that an Intel Core 2 Duo is faster than a G5, but how is it faster than the Quad? What exactly makes the Intel faster than the G5? I am looking at the Apple specs of the Quad and to me, it looks like a really solid computer, especially for 2005.

    2 Dual Core 2.5GHz PowerPC Processors
    1MB Cache Per Core (4MB Total)
    FSB 1.25GHz Per Proc
    Up to 16GB DDR2 PC2-4200

    So, what makes the G5 Quad, or even Dual Core/Dual Proc G5's so weak?
     
  2. macrumors P6

    dukebound85

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    #2
    old tech from circa 2005 vs new tech in 2009 has a role
     
  3. thread starter macrumors 68020

    noodle654

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    #3
    Ohh...my mistake, when they first came out with the Mac Pro.
     
  4. macrumors 6502a

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    Mar 4, 2008
    #4
    You answered the question yourself... for 2005, not 2009.
     
  5. macrumors 603

    SkyBell

    Joined:
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    Location:
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    #5
    It isn't... it's definitely equivalent then most of the Core Duo machines, and even some C2D's.
     
  6. thread starter macrumors 68020

    noodle654

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    #6
    Well...how is it comparable to my 2.2GHz MBP...

    The way I think of it, wouldnt the G5 Quad be faster than my MBP?
     
  7. macrumors P6

    dukebound85

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    #7
    why would you get a g5 now? you will be forever stuck with leopard
     
  8. macrumors 6502a

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  9. thread starter macrumors 68020

    noodle654

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    #9
    What's wrong with Leopard? If I am able to get a G5 for very cheap, why wouldnt I get it?
     
  10. macrumors 604

    iBookG4user

    Joined:
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    Location:
    Seattle, WA
    #10
    According to Geekbench the G5 will be slightly faster. So if it is a good enough deal and it fits your needs, go for it. But realize the limitations that you're buying a computer which will not be able to run the latest operating systmes and developers will slowly move to intel programs only.
     
  11. macrumors 65816

    voyagerd

    Joined:
    Jun 30, 2002
    Location:
    Rancho Cordova, CA
    #11
    The Quad G5 is faster, as per Geekbench scores. Since the computer is 4 years old, it doesn't have much future in it though. My G5 just acts as a table to put my MBP on currently. I'd compare the 4 core G5 prices with the earliest Mac Pro prices. Even the 2GHz Mac Pro beats the G5 by quite a bit.

    MacBook Pro (Mid 2007)
    Intel Core 2 Duo T7500 2.2 GHz (2 cores) 2836

    Power Mac G5 (Late 2005)
    PowerPC G5 (970MP) 2.5 GHz (4 cores) 3244
     
  12. macrumors P6

    dukebound85

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    #12
    nothing

    i just dont see the point in buying hardware that will no longer be supported

    do what you want though
     
  13. macrumors 601

    andiwm2003

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    Location:
    Boston, MA
    #13
    there are people still using G4 Powerbooks and they run fine with leopard. If you get it really cheap (less than $250) then go for it I would say. It will work fine for another three years. However you might not get the newest software anymore because eventually developers will deliver Snow Leopard software only.

    But for a few years it should be fine. Right now its twice as fast as my 2.4GHz MBP and 8 times as fast as my PB G4.:eek:
     
  14. thread starter macrumors 68020

    noodle654

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    #14
    Thank you for these...I have a question though. It seems like per core, the Intel C2D is much faster than the G5 Quad, why exactly?
     
  15. macrumors regular

    Ti_Poussin

    Joined:
    May 6, 2005
    #15
    I have own a G5 quad, and it's pretty damn fast, my iMac with a Core2Duo seem like a slow molasse after running for a years on those beast. As the speed point of view, the G5 can handle pretty much anything you can throw at him. It's fast bus system and multiple core make it a wonderful machine for running many heavy task at the same time.

    The only bummer, is the support for Snow Leopard. But if you can get it cheap and don't mind Leopard or a 32/64 bit Linux, it's a good machine. Make sure to cheek for water cooling leak before buying, there was a problem on a part of the series.

    If I could choose to have a Quad G5 or a core 2 duo, I would choose the quad G5, as for comparing it to a quad Xeon is another story, but different price range also.
     
  16. macrumors 68040

    California

    Joined:
    Aug 21, 2004
    #16
    My Quad and same late 2005 revision 2.3ghz Dual Core PM G5 with 11 gigs of ram and the Quadro video card run circles around my MB Aluminum 2.4 with four gigs of ram that I just sold. The geekbench scores on those lists rate them with stock, oem or limited ram, which is a shame.

    The 2.3 is not quite as fast as the Quad of course but right up there.

    If you don't care about Snow Leopard and can get a good deal, they are great machines.

    I am VERY content.
     
  17. macrumors 603

    richard.mac

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    #17
    upgrade the G5 with as much RAM as you can afford and the latest, fastest standard hard drive like the Seagate 7200.12 or WD Caviar Black then it will be a snappy machine.

    the Intel processors are probably a bit faster than the Quad Core G5 in the Macs but its not a huge difference in everyday usage. a large difference wouldnt be noticed until you fully load the processor/s.
     
  18. macrumors 601

    OrangeSVTguy

    Joined:
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    Location:
    Northeastern Ohio
    #18
    If you can find a quad for less than $700 than that is a very good deal. Like others have mentioned, check for leaks first and check often. High revving fans or kernal panics are typically the first signs of a leak.

    The G5 will run Leopard just fine for many years to come. So what that it won't run the latest and greatest, if the current software is good and fast enough for you, then it will be good and fast enough for you a few years from now.

    I'd say in maybe 4 years, the Mac Mini will absolutely smash any pre-intel machine as it will probably have 16 cores and support 128gb of memory. :D
     
  19. macrumors 65816

    Dr.Pants

    Joined:
    Jan 8, 2009
    #19
    I *bought* a Quad recently, and really enjoy it. Sure, a MacPro would be faster, but my budget shrunk due to some... unexpected tuition :eek: And RAID costs money, along with non-academic FCS2! I am in the process of upgrading it; insofar, its a very nice machine. I perfer it over the Intel iMacs I used in my visual communications class; I guess I am an expandability sucker :p

    That's beside the point though - the point is I wanted to run Final Cut and a RAID array, and I just didn't have the money for a first-gen MacPro to put into my budget. A G5 sufficed everything I wanted. Sure, its not as powerful as some other machines, but it gets the job done better then a lot of the others, too.

    As for the OS, all I can say is that on the update will 10.5 stop working? Nope - it will also run FCS2 for some time to come. In a few months I also plan to replace the conductive, corrosive coolant with a nonconductive noncorrosive one - just being a chem/physics geek/major, I want access to my universitys new labs to run some "extracurricular" tests.:D ((For the initiated, heat capacity, viscosity, and density in comparison of the original liquid to the replacement))
     
  20. macrumors 6502

    Joined:
    Feb 18, 2008
    #20
    Then factor in my machine for similar price.

    Processor Name: Dual-Core Intel Xeon
    Processor Speed: 2.66 GHz
    Number Of Processors: 2
    Total Number Of Cores: 4
    L2 Cache (per processor): 4 MB
    Memory: 5 GB
    Bus Speed: 1.33 GHz

    Then add snow leopard wont run on your g5, will run on my machine, new 4870 will run on my machine, so OpenCL will make the Intel quicker again etc. Lots of apps no-longer run properly on PPC, Where they are Intel native(CS4 etc).

    Must i continue? I had you at the front side bus and clock speed, before we even went to the new OS due in september and OpenCL that is brought with it :)

    Its not them being weak, they are a decent machine, it is more that apps and OS are no longer written to be natively run on them. You may as-well be buying a machine and running OS9 or windows 3.1 IMO -> A dead technology.

    I bought a G5 tower at the start of the intel transition, got it for a good price second hand, resold it once i had saved enough for my current machine. Even back then I was having issues with apps being for PPC.
     
  21. macrumors 603

    SkyBell

    Joined:
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    Location:
    Texas, unfortunately.
    #21
    Just a newer technology... things like that happen.


    The Quad G5 is still a beast though. :D
     
  22. macrumors 65816

    300D

    Joined:
    May 2, 2009
    Location:
    Tulsa
    #22
    The guaranteed-to-die liquid cooling system for one.

    1, its PowerPC. 2, its 4 year old technology. 3, the Intel is much more efficient.
     
  23. macrumors 68030

    ReanimationLP

    Joined:
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    #23
    The nice thing about these though is you can load it up with 16GB of RAM for less than 160.
     
  24. macrumors 68030

    Catfish_Man

    Joined:
    Sep 13, 2001
    Location:
    Portland, OR
    #24
    There are many many reasons why this. I'll list a sampling of them, but there's hundreds (likely many thousands) of small reasons.

    * Manufacturing process: the transistors
    and wires in the Core 2 Duo are smaller (due to being made on newer manufacturing equipment), allowing reduced power usage and/or increased speed. Intel's also made some innovations with the materials used recently (google "high-k dielectric").
    * Load/store reordering: the C2D has a lot of flexibility in what order it loads data from memory, allowing it to reduce the amount it has to wait. It can even do things like start loading some data ahead of a store, then cancel and restart the load if it turns out that the store was to the same address (overwriting the data that would have been loaded).
    * The G5's instruction issue limitations: The G5 is very picky about how instructions are grouped, and programs that don't take this into account sometimes end up missing out on a good bit of its speed.
    * Bigger caches: another benefit of smaller transistors is just that you can use the extra space freed up by them to add things like gigantic caches. Intel also seems to be able to design caches that are both very fast and large. I don't know how they manage that.
    * The G5's rather high memory latency: While the G5 had tons of memory bandwidth, its latency was pretty awful.
    * Branch prediction: C2D has a very advanced branch predictor including a loop end predictor and assorted other clever ideas
    * The G5's slow integer units: Even the simplest integer operations take two cycles to complete on a G5, making it difficult to schedule some code for optimum throughput (you have to interleave dependent integer math with other operations).
    * Memory prefetching: Both chips do pattern recognition in order to predict loads, but the C2D implementation of it is apparently extremely good.


    Overall, my expectation would be:
    * The C2D will absolutely destroy the G5 for tasks like compiling, or running javascript. These are memory latency sensitive, integer/branch sensitive, and use caches well (strong temporal locality).
    * The G5 will compete well on things that emphasize bandwidth over latency, straight-line code over branches, and floating point math over integer. In particular, vector code (altivec for the G5, sse 1-4 for the C2D) should be competitive.
    * Most day to day applications either don't use the CPU heavily (common) or fall somewhere in between these extremes, but significantly more towards what the C2D is good at.

    Sadly for the G5, most of the things it's good at happen to also be the things GPUs are good at. The things it's bad at tend to be the day to day tasks of using a computer. Not unexpected for a cut-down server chip I suppose.
     
  25. macrumors 601

    Umbongo

    Joined:
    Sep 14, 2006
    Location:
    England
    #25
    There are few things that have been touched on here that would really make me think twice.

    Well known issure of liquid cooling leakage: This completely rules out any possibility for me.

    Lacking graphics card options: Even if your workflow isn't GPU based, its nice to have performance if you need it. Many applciations are going to be utilizing this more in the future.

    PPC: Performance wise it may still be enough, but its not just Apple operating systems that are going Intel only. Most software will go this way.

    Out performed by 2GHz 2006 Mac Pro: This is perhaps more a budget one, but you can find these cheap from time to time. Like close to $1,000. Now we don't know your finances or how much the G5 is available for, but if you are talking ~$700 then for several hundred more you can get a lot of expandability (upgrade to 8 cores for under $600 easily, power graphics card options) and future support.

    I'm sure there are plenty of people who have slower systems than the G5 you are looking at that will last them many more years, and some who would be fine with such a system now. It's not like it got slower since 2005, just newer software is more demanding and you may be able to better use the money.
     

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