Hyper threading question and Mac Pro consideration...

Discussion in 'Mac Pro' started by Crunch, Jul 6, 2014.

  1. Crunch macrumors 6502

    Crunch

    Joined:
    Jun 26, 2008
    Location:
    L.A. (although currently overseas)
    #1
    I'm getting close to pulling the trigger on a Mac Pro and wanted to know if it's a good idea to either upgrade to the D500's and/or a 6-core CPU seeing that I want to drive one 4K display and possibly also use it as a server?

    I also wanted to know about Hyperthreading. And yes, I've google'd, etc., and basically understand what it is, but I still have a very specific question:

    Apple always says that OS X is designed to take advantage of all the cores and threads. Why then am I always discouraged from buying a Core i7 with Hyperthreading over the Core i5 that I currently have? Wouldn't something like Safari open faster with the additional threads? Wouldn't navigating the OS be a bit more responsive?

    Thanks very much! :)
     
  2. simsaladimbamba

    Joined:
    Nov 28, 2010
    Location:
    located
    #2
    Navigating the OS does not take that much CPU power in almost all circumstances, even a Core2Duo is sufficient for that.
    Opening Safari or other applications is sped up by the storage device's speed and latency, thus starting from an SSD is almost always faster than from an HDD.
    If you would have an i7 and an HDD, Safari would not open faster than it would on a Core2Duo with an SSD.

    The CPU power is used for computations beyond navigating the OS, thus maybe with your stated needs (Safari and server) a Mac mini will do just fine, though the ability to drive a 4K display is not available in that machine.
     
  3. Draeconis macrumors 6502a

    Joined:
    May 6, 2008
    #3
    With Safari open I currently have 23 threads, so yes, i7 performance even at the same clock speed as an i5 would be increased because of hyper-threading.

    The D300/D500/D700s can all drive a 4K display, it's more pertinent understand your needs before recommending a particular GPU. It's also worth noting that (currently) you can't change the GPUs, so it might be worth getting a better GPU now so you possibly don't regret it later.

    The D500s were also benchmarked by many sites (Anandtech, Ars Technica) and found to be a bit of a weak point; if you require just 4K, D300s are fine. If you need decent GPU performance, I'd say ignore the G500 and opt for the D700.
     
  4. AidenShaw, Jul 6, 2014
    Last edited: Jul 6, 2014

    AidenShaw macrumors P6

    AidenShaw

    Joined:
    Feb 8, 2003
    Location:
    The Peninsula
    #4
    idle threads aren't relevant

    Threads only use logical CPUs when they are busy (computing). Your idle Safari threads aren't using any resources beyond a small amount of memory.

    Hyper-threading can slow the system down if you don't have lots of busy threads.

    My rule is to disable hyper-threading unless my load (or an important part of the workflow) has more busy threads than physical cores. In other words, if you not seeing close to 100% CPU utilization of the physical cores - don't turn on hyper-threading.

    On the other hand, if you have 100% of the logical cores busy hyper-threading can be very useful.
     
  5. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #5
    Is there any way to disable Hyperthreading in Mavericks?
     
  6. AidenShaw, Jul 6, 2014
    Last edited: Jul 6, 2014

    AidenShaw macrumors P6

    AidenShaw

    Joined:
    Feb 8, 2003
    Location:
    The Peninsula
  7. TzunamiOSX, Jul 6, 2014
    Last edited: Jul 6, 2014

    TzunamiOSX macrumors regular

    Joined:
    Oct 4, 2009
    Location:
    Germany
    #7
    You normally dont need to disable HT, OSX is managing the the system. HT will only used when all other real cores are near 100%.

    Every second row is the HT part
     

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