New Mac Pro En Route

Discussion in 'Mac Pro' started by mlankton, Mar 30, 2009.

  1. mlankton macrumors newbie

    mlankton

    Joined:
    Mar 30, 2009
    #1
    Power supply on my dual 2.0 G5 went poof, and it was almost upgrade time anyway. Had been waiting for Nehalem, but once I started really studying the new vs the old, I decided that I'd rather get a Harpertown octo than a Nehalem quad.

    Couldn't afford a new octo, didn't like the 6 gb ceiling on the new 2.66 quad, and in the end after a week of homework, decided a Harpertown 2.8 octo was the better choice for me.

    Should be here Thursday. Adding 8 gigs of Mushkin ram right away, and I'll plug the last two slots next month (the mac pro + memory left me cash poor) for a total of 14 gigs.

    Really stoked about the new box. Absolutely no buyer's remorse. Ultimately would have liked to have one of the new 2.93 octos, but at 2450.00 and a couple hundred extra for more ram, I have a feeling that the new box will keep me happy for the next 5 years, just like my G5 dual, and the G4 I had before that.

    If any of you are on the fence about the Harpertown octo vs the Nehalem quad, make up your minds quick, 'cause I don't think the remaining octo stock is going to last long. In this instance I think the people who jump on the older octos are going to be very happy with the computer they are getting for the $

    My $.02
     
  2. ksz macrumors 68000

    Joined:
    Oct 28, 2003
    Location:
    San Jose, CA
    #2
    Probably just a typo, but the new quad-core has a 16GB ceiling, albeit an expensive one at nearly $980 from OWC. It's considerably cheaper to equip the Harpertown with 16GB ($359).

    My 2.8GHz octo-core Harpertown is performing wonderfully and I have no Nehalem-envy! However, those who need the increased power are perfectly justified in purchasing the new models (even at the higher prices).

    I, however, feel that the price/performance ratio of the 2.8 GHz Harpertown remains unbeaten, especially so with recent price reductions.

    I regularly run 2 virtual machines (SuSE Enterprise Linux and Windows XP) for work-related activities (the s/w we develop has a Windows client and Linux server) with just wonderful performance. Two cores are dedicated to Linux, two to Windows, and I still have 4 left over for Mac. Put all of this on a 30-inch monitor and you've got yourself a pretty satisfying setup!
     
  3. cmaier macrumors G3

    Joined:
    Jul 25, 2007
    Location:
    California
    #3
    Not really a 16GB ceiling either (probably). Figure that in a few years higher density (8GB) dimms will be available at fairly reasonable prices, and, depending on your memory needs, you may be able to upgrade the RAM faster than your memory needs increase.
     
  4. mlankton thread starter macrumors newbie

    mlankton

    Joined:
    Mar 30, 2009
    #4
    Yeah I suppose it is 12 with the 4gb sticks, but they cost too much. Everything I've read on the new quads suggests that you damage performance running all four slots, compared to running three.
     
  5. cmaier macrumors G3

    Joined:
    Jul 25, 2007
    Location:
    California
    #5
    Don't believe that. While my Ph.D. dissertation was entitled "High Speed Microprocessor Cache Memory Hierarchies For Yield-Limited Technologies," I haven't seen the circuits behind the Nehalem memory controller, but I believe what you see on the tests is this:

    Average speed=((super fast)*3 slots+(slow)*1 slot)/4 slots.

    In other words, once I add a dimm in the fourth slot, if I use all the memory (i.e. the memory in all slots), the overall average bandwidth goes down. The accesses to the first three slots are still fast, but the fourth slot goes slower.

    However, I am accessing MORE MEMORY at this slower speed, which means the overall performance of the system actually is BETTER. If I need to access that much memory, I am MUCH better off accessing it even at single or dual channel speeds than I am paging to a hard drive!
     
  6. ksz macrumors 68000

    Joined:
    Oct 28, 2003
    Location:
    San Jose, CA
    #6
    The current limit, based on what's available on the market, is 16GB. You will lose some memory performance by populating all 4 DIMM slots because DDR3 is most efficient in multiples of 3. However, because of Nehalem's on-chip memory controller, you will still get better memory I/O compared to Harpertown.
     
  7. mlankton thread starter macrumors newbie

    mlankton

    Joined:
    Mar 30, 2009
    #7
    Yeah, I'm sure there is much improved in the Nehalem core vs Harpertown.

    I'm just excited about getting 8 real cores for less than $2500. It's nice that people in the market for a entry level Mac Pro have two valid choices at the moment, and I'm also sure that the 2.66 quad is more than enough machine for most who will buy it.
     

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