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.


--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

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


--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

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.


--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

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

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

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.


--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

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.

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

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.


--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)