Interpretation of markings on DDR3 SDRAM.

Oct 21, 2025 Last reply: 8 months ago 6 Replies

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.


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.

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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).

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.

Thanks, ... P.

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

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

Theo

Photo here.

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This may be a replacement but 8500S vs. 8500R is a complication.
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... P.

That's a fullsize server DIMM, not a SODIMM. It won't fit, completely different sockets.

Theo,

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

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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