Crucial (Micron) vs OWC Memory for MacPro 7,1

There is no inherently BAD RAM on the market from major vendors today. But without being extremely careful, you could end up with RAM that works perfectly, but does not happen to be the correct RAM for your computer.

OWC and Crucial in the US comes with a money-back guarantee, and a lifetime warranty. I epect they operate under the same rules in the UK.

OWC has a lab full of Macs. They plug modules into Macs and run them. Problem module-types are removed from their product line.

Crucial has a reputation for using their database of 'which sales "stick"' to determine what to keep recommending.

Both companies are likely to have memory tester machines that can test modules at much higher speeds than you can attain while executing the diagnostic on the same machine.

Regarding "pairs": if you get modules that are not at least strongly similar, (like different manufacturers) send some or all of them back.

Note that

• Registered (R-DIMM) or Load-Reduced DIMM (LR-DIMM). Do not mix R-DIMMs and LR-DIMMs.

Mac Pro has a 6-channel memory controller that supports 12 memory slots 

That means that they should be installed in pairs. It appears that hat Mac, like other some other Mac Pros can run either dual or triple channel memory which is a little faster than single channel with triple channel also being faster than dual channel.

I wou get 6 identical ones with the vendsya they will work together.

All Mac Pro models and the iMac pro feature Error-Correcting Code RAM.

Memory problems do not fester undetected on these Macs -- RAM memory works perfectly until the machine halts with an uncorrectable error.

The error correction hardware is used VERY aggressively at Startup. ANY error, correctible or not cause the associated slots to be declared "empty" and they will not be used by MacOS. You will know whether these modules work or not in a few seconds.

User Tip: Mac Pro and Error Correcting Co… - Apple Community

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