rosindabow

Q: Memory speed differs from chip

I just purchased a used Mac Pro.  The specs are as follows: Dual 6 core 2.4GHz Xeon.  It came with 24 Gbs of memory but the model of the memory chip comes up in system report as: 1066MHz DDR3 ECC SDRAM.  I checked the specs of the model number, and I do have the original box that has the same serial number on it so I'm pretty sure this is all legit.  The specs for the memory chips listed for this machine are 1333MHz DDR3 ECC SDRAM.  So I thought maybe they added the worng memory chip.  Opened up and sure enough, I pulled out four 2Gb hynix chips withe following written on them: 2Gb 1Rx8 PC3-10600E-9-11-D1. And on the next line: HMT325U7CFR8C-H9 TO AB 1229.  I'm not sure if these are or arent; 1333MHz. I looked at the other four 4Gb chips and the were very clearly listed as the 1333MHz DDR3 ECC SDRAM.  So I removed what I thought were the offending chips and thought my memory would come up as 1333MHZ - it did not.  It is still reading 1066MHz.  I opened the amchine again and inspected each chip and they all read 1333MHz.  What could be wrong here?  The original specs on a base model of this machine absolutely call for 1333MHz - but they also said it comes with only 12Gbs of memory.  This machine has 16 od the 1333MHz and 8 of I'm not sure.  Does it need to be reset once it has used 1066MHz?  I assume it down-clocked itself relative to the incorrect chips but now that they have been removed, why doesn't it read as it should?  Any ideas?  Thanks.

Mac Pro, OS X Mavericks (10.9.1), 16 GB 800 MHz DDR2 FB-DIMM

Posted on Feb 28, 2014 10:01 PM

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Q: Memory speed differs from chip

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  • by rosindabow,

    rosindabow rosindabow Feb 28, 2014 10:08 PM in response to rosindabow
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    Feb 28, 2014 10:08 PM in response to rosindabow

    Update:  I just punched in the second set of numbers and the memory did come up rated as 1333MHZ chips from Memory4Less.  So why is my machine running at 1066MHz?

  • by kaz-k,

    kaz-k kaz-k Feb 28, 2014 11:05 PM in response to rosindabow
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    Feb 28, 2014 11:05 PM in response to rosindabow

    If your Mac Pro is installed mixed speed memories, all of memory speed adjusts lower speed one, in this case 1066MHz.

    Try resetting SMC as well as NVRAM.

  • by rosindabow,

    rosindabow rosindabow Mar 1, 2014 1:05 AM in response to kaz-k
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    Mar 1, 2014 1:05 AM in response to kaz-k

    Hi - That's just it - it does NOT have mixed speed memory chips.  They are all rated at 1333MHz.  None of the chips run at 1066MHz and yet that is what the system report says ... Strange ...  Any other ideas?

  • by The hatter,

    The hatter The hatter Mar 1, 2014 8:13 AM in response to rosindabow
    Level 9 (60,935 points)
    Mar 1, 2014 8:13 AM in response to rosindabow

    Is this a 55xx processor or not? is it a 4,1 or a 5,1?

     

    People have updated their firmware from 4,1 to 5,1 just to better use 1333MHz.

     

    Also depends on the cpu.

     

    Will there be any real performance difference in any actual applications?

  • by rosindabow,

    rosindabow rosindabow Mar 1, 2014 8:33 AM in response to The hatter
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    Mar 1, 2014 8:33 AM in response to The hatter

    It's a mid 2012 5,1 - it came in the actual box.  Not sure aif there will be any real performance difference, just beginning the process of installing everything ... that's why I'm posting.  These are most defintiely 1333MHz chips and Appple says it runs these chips with this machine, just not showing up as 1333MHz -  not sure why ...

  • by The hatter,

    The hatter The hatter Mar 1, 2014 9:05 AM in response to rosindabow
    Level 9 (60,935 points)
    Mar 1, 2014 9:05 AM in response to rosindabow

    Maybe even though it is a 56xx series it just doesn't but it all depends on the SPD programming I assume, batches being the same, same ranking.

     

    This is the 5620

    http://ark.intel.com/products/48768/Intel-Xeon-Processor-E5645-12M-Cache-2_40-GH z-5_86-GTs-Intel-QPI

  • by rosindabow,

    rosindabow rosindabow Mar 1, 2014 1:31 PM in response to The hatter
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    Mar 1, 2014 1:31 PM in response to The hatter

    How can I find out if that's the Intel Xeon processor in this computer?

     

    I just looked at EveryMac.com and this is what they post about my computer: 

    "The Mac Pro "Twelve Core" 2.4 (Mid-2012/Westmere) is powered by dual 2.4 GHz Six Core 32-nm Xeon E5645 (Westmere) processors with a dedicated 256k of level 2 cache for each core and 12 MB of "fully shared" level 3 cache per processor."

     

    They go on to say:  "By default, this model is configured with 12 GB of 1333 MHz DDR3 ECC SDRAM, a 1 TB (7200 RPM, 32 MB cache) 3Gb/s Serial ATA hard drive, an 18X dual-layer "SuperDrive" and an ATI Radeon HD 5770 graphics card with 1 GB of GDDR5 memory."

     

    So as far as I can tell, this is the correct type of memory, could this processor just not run the memory at the higher clock speed?

  • by Grant Bennet-Alder,

    Grant Bennet-Alder Grant Bennet-Alder Mar 1, 2014 2:15 PM in response to rosindabow
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    Mar 1, 2014 2:15 PM in response to rosindabow

    How many DIMMs and in what slots?

     

    In some cases, populating the fourth slot on a side may throw the machine back one step from 1333 to 1066.

     

    Also, certain types of DIMMs that are "two rank" present two Bus loads, and these sometimes slow things down as well.

  • by The hatter,

    The hatter The hatter Mar 1, 2014 2:21 PM in response to rosindabow
    Level 9 (60,935 points)
    Mar 1, 2014 2:21 PM in response to rosindabow

    iStatPro and others will show more about your hardware. Amazing. On Windows you have much more information available at your fingertips as to complete range of "system information/profile" as to memory timings, voltage, fans, t emps, BIOS, all t he devices and their vendor as well as installed driver. I use both but I have grown away from using OS X as much.

     

    www.macupdate.com if not App Store for Temperature Monitor, anything like CPU-Z type.

     

    What you are quoting is just marketing material.

  • by rosindabow,

    rosindabow rosindabow Mar 11, 2014 12:26 AM in response to rosindabow
    Level 1 (129 points)
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    Mar 11, 2014 12:26 AM in response to rosindabow

    Hi all.  I found this note which I beieve explains my predicament:  http://support.apple.com/kb/HT4433?viewlocale=en_US#1

     

    Here it clearly states that "although the memory speed of the UDIMMS is 1333 MHz, they will operate at 106 6MHz or 1333 MHz depedning on the processor in the computer."  I guess for a 2.4 GHz machine, the speed of the memory is 1066 MHz.

  • by The hatter,

    The hatter The hatter Mar 11, 2014 7:01 AM in response to rosindabow
    Level 9 (60,935 points)
    Mar 11, 2014 7:01 AM in response to rosindabow

    which is why people upgrade to 5,1 firmware and 36xx/56xx processors - though memory bandwidth is not huge improvement if any. IF you could get 1866/1600MHz even... 2.4GHz though is holding your system back more than anything. RAM and SSDs can help alleviate that somewhat.