The i5 doesn't have Hyper-threading and only has 4 cores, i7 does and has 8

Discussion in 'iMac' started by MythicFrost, Oct 28, 2009.

  1. MythicFrost macrumors 68040

    MythicFrost

    Joined:
    Mar 11, 2009
    Location:
    Australia
    #1
    I just realized I think it was early this morning that the i5 iMac does not have hyper threading, so it's just a quad core, the i7 is a quad core but has HT so OSX recognizes eight cores.

    Did anyone actually know this? I thought I'd post this just in case some people didn't.
     
  2. Eidorian macrumors Penryn

    Eidorian

    Joined:
    Mar 23, 2005
    Location:
    Indianapolis
    #2
    It's not that hard to read all this off of Apple's own iMac specification page.

     
  3. Bryan Bowler macrumors 68040

    Joined:
    Sep 27, 2008
    #3
    Thanks for the insight Sherlock.
     
  4. ronaldcastillo macrumors 6502a

    Joined:
    Oct 25, 2009
    #4
    If it recognizes 8-cores why is it considered as a quad core?
     
  5. dukebound85 macrumors P6

    dukebound85

    Joined:
    Jul 17, 2005
    Location:
    5045 feet above sea level
    #5
    because it has 4 cores
     
  6. Chundles macrumors G4

    Chundles

    Joined:
    Jul 4, 2005
    #6
    Because it is a quad core machine. It has four physical processing cores. Each of these cores however can do two things at once (to put it simply) so the processor shows as having 8 logical cores.
     
  7. PenguinPower macrumors member

    PenguinPower

    Joined:
    Jun 23, 2009
    #7
    Humm, it appears that even mac forums have trolls? I thought they didn't get viruses? ;p
     
  8. MythicFrost thread starter macrumors 68040

    MythicFrost

    Joined:
    Mar 11, 2009
    Location:
    Australia
    #8
    Wow, there's no need to be rude I was just trying to help anyone who didn't know.
    I don't know if that was meant to be rude or not but it came across that way, and yes I know I read it there after someone told me the i5 didn't have HT, until then I didn't have a clue.
    That's just rude.

    I was just trying to help...
     
  9. Eidorian macrumors Penryn

    Eidorian

    Joined:
    Mar 23, 2005
    Location:
    Indianapolis
    #9
    Virtual cores are still well, virtual.

    There is some performance scaling in certain situations from hyperthreading but nothing beats the real thing.
     
  10. Maserati7200 macrumors 6502a

    Maserati7200

    Joined:
    Mar 17, 2009
    Location:
    11230, Midwood, Brooklyn, NY, USA, North America
    #10
    Question: would I notice the difference on an iMac? I usually have 5-12 apps open at once, I edit 720p video (may edit 1080p in the future), use garageband, iphoto, and handbrake. Would there be a significant difference between an i5 and i7 in those areas?
     
  11. MythicFrost thread starter macrumors 68040

    MythicFrost

    Joined:
    Mar 11, 2009
    Location:
    Australia
    #11
    I would say yes, you'd get more benefit from an i7 although I can't be sure.
     
  12. Eidorian macrumors Penryn

    Eidorian

    Joined:
    Mar 23, 2005
    Location:
    Indianapolis
    #12
    Do you plan on doing some of those tasks simultaneously?
     
  13. meagain macrumors 68030

    Joined:
    Nov 18, 2006
    #13
    Mythic - While I did know the answer to your title post, it took me a while to get there by digging around. I know your post will be helpful to many.

    I've opted for the i7 mostly for dealing with HD video. What a PITA that is. I hope to be able to multi-task while processing it, etc. The benchmarks I've read imply the i7 will help greatly so I'm rolling with that. I figure for $200 over 3 years? of ownership, if that saves me time, allows me to do tasks simultaneously, etc. - then it's worth it to me big time.

    One thing that bothers me is that I've read a few blurbs where pro-audio people (studio type situations) turn off hyperthreading. I have no idea how old those posts were and I don't think they were macs - but it sort of concerned me. I wonder why? I also wonder if it's possible to shut it off on our Macs if warranted.
     
  14. MythicFrost thread starter macrumors 68040

    MythicFrost

    Joined:
    Mar 11, 2009
    Location:
    Australia
    #14
    Thank you, as intended :)
    What's a PITA?
    I believe Pro Tools had a problem with the hyper-threading on the Nehalem Mac Pro, I don't remember what but I think it was pretty bad, I think it's been fixed but I don't know.
    I'm not sure about any audio production tools/software. It probably is possible to turn the HT off.
    Can anyone clarify on this?
     
  15. mgzilla macrumors member

    mgzilla

    Joined:
    Sep 28, 2009
    Location:
    New Jersey
    #15
    [​IMG]
     
  16. itommyboy macrumors 6502a

    itommyboy

    Joined:
    Feb 26, 2009
    Location:
    Titletown USA
    #16

    Lolz nice one noobs! :D
     
  17. Chundles macrumors G4

    Chundles

    Joined:
    Jul 4, 2005
    #17
    Pain In The Arse
     
  18. Bryan Bowler macrumors 68040

    Joined:
    Sep 27, 2008
    #18
    MythicFrost,

    Ok, here's the deal. Some of us are giving you a hard time because you are posting something that been discussed over and over since the iMac has been released. If you took some time to look around, you find no less than 15 or 20 threads that discuss this issue.

    It's akin to getting on and saying, "I just realized that the new iMacs have bigger screens. I thought I'd post this in case you didn't know."

    Bryan
     
  19. MythicFrost thread starter macrumors 68040

    MythicFrost

    Joined:
    Mar 11, 2009
    Location:
    Australia
    #19
    Can people just stop posting this kind of stuff, I don't like it.

    @Chundles: thanks.
    Yes it's probably been discussed in the context of large threads, this was a thread purely about this, for those who don't read through incredibly large posts and may miss it.
    It's obvious the iMacs have bigger screens, it's advertised everywhere however "Core i5 does not have HT" is not advertised everywhere, I've read the spec page for the iMac about 5 times if not more, and missed it every time.

    And in the case that someone did post the new iMacs have bigger screens, I would have either not replied if I knew and say thanks if I didn't.
    I posted this just to help anyone who didn't know, that's why the title said what it said to attract those who didn't know, compared to "I just realized the i5 didn't have HT".

    Considering this was serious and only intended to help anyone who may have missed this little bit of info like I did, I don't understand why I get harsh posts, if it really bothers you that I posted it then it would seem logical to not post and ignore it.
     
  20. Rapmastac1 macrumors 65816

    Rapmastac1

    Joined:
    Aug 5, 2006
    Location:
    In the Depths of the SLC!
    #20
    For audio editing the i5 would do you plenty good. But if you plan on editing 1080p, I'm more than certain the graphic card in the high end iMac won't cut it too well. If I were you, I would wait until the new Mac Pros are released and get a previous gen Mac Pro with a higher end video card in it, this will give you better performance imo.

    I'm not due to upgrade my computer for one more year (mid August to mid November every two years), but I'm really considering a Mac Pro over an iMac (especially since I plan on keeping my current iMac instead of selling it off). I want to do editing in 1080p as well as get into some cool multimedia projects that are fairly graphic intensive. And with the audio I'm working with, I need a much better audio card than a one output port on the iMac. The current generation of the Mac Pro, with just four cores, mid range ghz, higher end graphics, and 8 to 12 gigs of ram should do me just fine. Of course by the time I buy the newer Mac Pros will have already been out.

    And I didn't know they had double virtual cores, which is good but I could only imagine as good as Apple implements it. I don't think it will work at all on the Windows side.
     
  21. Eidorian macrumors Penryn

    Eidorian

    Joined:
    Mar 23, 2005
    Location:
    Indianapolis
    #21
    Please elaborate.

    I'd definitely wait for next year's Mac Pro. The expansion capability is nice on the Early 2009 model but the raw computing hardware is lackluster.

    Please elaborate.
     
  22. Bryan Bowler macrumors 68040

    Joined:
    Sep 27, 2008
    #22
    Mythic, I'm sorry, but this is an open discussion board and discussions take place. If you don't like what someone says, then thicken up and don't let it get to you. My sarcastic remark was not meant to hurt your feelings, so I am sorry for that.

    Bryan
     
  23. MythicFrost thread starter macrumors 68040

    MythicFrost

    Joined:
    Mar 11, 2009
    Location:
    Australia
    #23
    Thank you, and apology accepted (I appreciate it) :)
    Yeah, all I can do is bring it to someone's intention if they upset me.
    I'm sensitive, I have my reasons.

    If you are referring to the Core i7 having an additional 4 virtual cores, the OS just recognizes 8 cores, if Windows couldn't make use of them then you wouldn't see them around as much I don't think.
     
  24. alphaod macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
    Location:
    NYC
    #24
    It has 4 physical cores, but 8 logical cores.
     
  25. 300D macrumors 65816

    300D

    Joined:
    May 2, 2009
    Location:
    Tulsa
    #25
    It has 8 logical cores, but two threads cannot try to use the same part of the processor at once.

    If you have 8 processes and 6 of them need the same specific function of a core, 2 processes are going to have to wait and share with the others.
     

Share This Page