MP 1,1-5,1 Mac Pro 3,1 RAM

[LookToWindward]

Hi,

Does anyone know where to buy extra RAM for the Mac Pro 3,1 in Europe?

AFAIK, the correct RAM to use is "800MHz DDR2 PC2-6400 ECC Memory". However I've seen RAM for sale on EBay.es that claims to be for the Mac Pro rated at 667MHz. Will this work?

All the Best
Dave

 

[LookToWindward]

I see that there are ECC and non-ECC versions, which type do I need?

 

[joevt]

For RAM info, you can go to https://eshop.macsales.com
click "My Upgrades"
select MacPro3,1
select Memory upgrades
All the RAM they sell is ECC 800MHz which matches the specs at https://support.apple.com/kb/sp11

This says you can use 667MHz with a small speed penalty:
https://everymac.com/systems/apple/...m-backwards-compatible-with-older-memory.html

If you install 64 GB of RAM, then you need to set some boot args to limit that to 62 GB in order to maintain full speed for macOS and Windows.
https://forums.macrumors.com/threads/mac-pro-3-1-nvme-support-upgrade-guide-questions.2194878/

 

[LookToWindward]

Thanks a lot, these references really helped. Yeah, I saw the OWC shop, but I'm in Spain and the cost is too high to import it. The shipping is at least $60 and then there's 21% tax added. I've found 64 GB 667 MHz RAM for 130 euros delivered. It says I will take a maximum speed decrease of 4%, which I can live with.

I guess you can't mix 800 and 667 in the same machine?

And can someone tell me what a "Matched Pair" is?

 

[uller6]

Mixed 667/800 MHz RAM will work in a Mac Pro 3,1, but will slow down all the RAM sticks to 667 MHz. You need to use ECC RAM in the 3,1; non-ECC RAM (regular RAM) will not work. When I had a 3,1 years ago I put 667 MHz ECC RAM in because the 800 MHz stuff was like 3X more expensive for the same capacity sticks, but there was a (minor) speed penalty.

 

[joevt]

These installation instructions discuss matched pairs:
https://eshop.macsales.com/tech_center/manuals/Memory/macpro.pdf

 

[LookToWindward]

Great, thanks a lot, that's the best description I've seen. 800 MHz is more like x 4 times more expensive for me. 64 GB or 130 Euros delivered. It was Nearly $400 on OWC including shipping and tax