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  • Interpretation of markings on DDR3 SDRAM.

    From peter@peter@easthope.ca to sci.electronics.repair on Tue Oct 21 10:18:43 2025
    From Newsgroup: sci.electronics.repair

    A Mac Mini has has two SDRAMs with this marking.
    1GB 1Rx8 PC3-8500S-07-10-B1

    This is a candidate replacement.
    4GB 2Rx4 PC3-8500R-07-10-0-D2

    What is the significance of the character following 8500?
    R and S.

    Thx, ... P.

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  • From Jeff Liebermann@jeffl@cruzio.com to sci.electronics.repair on Wed Oct 22 09:19:10 2025
    From Newsgroup: sci.electronics.repair

    On 21 Oct 2025 10:18:43 -0700, peter@easthope.ca wrote:

    A Mac Mini has has two SDRAMs with this marking.
    1GB 1Rx8 PC3-8500S-07-10-B1

    This is a candidate replacement.
    4GB 2Rx4 PC3-8500R-07-10-0-D2

    What is the significance of the character following 8500?
    R and S.

    The version of Mac Mini and the RAM manufacturer's names would be
    helpful.

    This will not answer your questions, but might be helpful.

    PC3-8500 is the same as DDR3-1066. <https://en.wikipedia.org/wiki/DDR3_SDRAM#Modules>
    See the 2nd column (Type) for the suffix designations.
    Note that both the "R" and "S" suffixes are not mentioned. Since it's
    Apple, it might be something "special". Looks like the letter suffix
    specifies CAS (Column Address Strobe Latency).
    --
    Jeff Liebermann jeffl@cruzio.com
    PO Box 272 http://www.LearnByDestroying.com
    Ben Lomond CA 95005-0272 AE6KS 831-336-2558

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  • From peter@peter@easthope.ca to sci.electronics.repair on Wed Oct 22 20:32:30 2025
    From Newsgroup: sci.electronics.repair

    In article <a50ifkp830ma8qq44g22pukjuq3dlurctg@4ax.com>, Jeff Liebermann <jeffl@cruzio.com> wrote:
    The version of Mac Mini and the RAM manufacturer's names would be
    helpful.

    Mac Mini
    Mac mini A1283 ... 2008.
    Model name: Mac mini
    Model identifier: Macmini3.1
    Processor name: Intel Core 2 Duo
    Processor speed: 2.26 GHz
    Number of processors: 1
    Total number of cores: 2
    L2 Cache: 3 MB
    Memory: 2 GB
    Bus speed: 1.07 GHz
    Boot ROM Version: MM31.00AD.800
    SMC Version (system): 1.35f1
    Serial Number (system): YM0120BU9G5
    Hardware UUID: 8EBA8096-3C6E-5B16-9EB6-C1D7599F27E8

    Memory cards are Samsung, made in China. If there's interest in
    a low res photo, I can post one tomorrow. May be able to post
    a better photo next week.

    PC3-8500 is the same as DDR3-1066. <https://en.wikipedia.org/wiki/DDR3_SDRAM#Modules>
    See the 2nd column (Type) for the suffix designations.
    Note that both the "R" and "S" suffixes are not mentioned. Since it's
    Apple, it might be something "special". Looks like the letter suffix specifies CAS (Column Address Strobe Latency).

    Thanks, ... P.

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  • From Theo@theom+news@chiark.greenend.org.uk to sci.electronics.repair on Thu Oct 23 14:25:13 2025
    From Newsgroup: sci.electronics.repair

    peter@easthope.ca wrote:
    A Mac Mini has has two SDRAMs with this marking.
    1GB 1Rx8 PC3-8500S-07-10-B1

    This is a candidate replacement.
    4GB 2Rx4 PC3-8500R-07-10-0-D2

    What is the significance of the character following 8500?
    R and S.

    https://www.kingston.com/unitedkingdom/en/memory/memory-part-number-decoder https://superuser.com/a/1027572

    Possibly S = SODIMM and R = ECC Registered DIMM (ie server memory).

    Have you confirmed the candidate is SODIMM and not full sized?

    Theo
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  • From peter@peter@easthope.ca to sci.electronics.repair on Thu Oct 23 20:50:06 2025
    From Newsgroup: sci.electronics.repair

    In article <a50ifkp830ma8qq44g22pukjuq3dlurctg@4ax.com>,
    Jeff Liebermann <jeffl@cruzio.com> wrote:
    ... the RAM manufacturer's names would be helpful.

    Photo here. https://easthope.ca/SamsungPC3.8500S.jpg

    This may be a replacement but 8500S vs. 8500R is a complication. https://www.ebay.ca/itm/175171932406

    ... P.

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  • From Theo@theom+news@chiark.greenend.org.uk to sci.electronics.repair on Fri Oct 24 10:52:28 2025
    From Newsgroup: sci.electronics.repair

    peter@easthope.ca wrote:
    In article <a50ifkp830ma8qq44g22pukjuq3dlurctg@4ax.com>,
    Jeff Liebermann <jeffl@cruzio.com> wrote:
    ... the RAM manufacturer's names would be helpful.

    Photo here. https://easthope.ca/SamsungPC3.8500S.jpg

    This may be a replacement but 8500S vs. 8500R is a complication. https://www.ebay.ca/itm/175171932406

    That's a fullsize server DIMM, not a SODIMM. It won't fit, completely different sockets.
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  • From peter@peter@easthope.ca to sci.electronics.repair on Fri Oct 24 06:59:08 2025
    From Newsgroup: sci.electronics.repair

    Theo,

    Thanks. I'm not so familiar with the DIMMs.

    In article <90s*USOpA@news.chiark.greenend.org.uk>,
    Theo <theom+news@chiark.greenend.org.uk> wrote:
    https://www.kingston.com/unitedkingdom/en/memory/memory-part-number-decoder https://superuser.com/a/1027572

    Possibly S = SODIMM and R = ECC Registered DIMM (ie server memory).

    Have you confirmed the candidate is SODIMM and not full sized?

    The card in the Mini is 67.6 mm wide. The card on eBay is
    probably 133.35 mm. I've asked the vendor for a confirmation.

    Thx, ... P.

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