32GB RDIMMs that work with MacPro5,1 are 4Rx4 RDIMMs, so, 1066 or 800MHz when installed to a Nehalem/Westmere Xeon.
Since the latency will be lower than at the nominal frequency, the penalty is not so much noticeable in the great scheme of things.
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Crazy idea. 32GB RAM modules in a cMP. Anyone tried this?
- Thread starter William Payne
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32GB RDIMMs that work with MacPro5,1 are 4Rx4 RDIMMs, so, 1066 or 800MHz when installed to a Nehalem/Westmere Xeon.
Since the latency will be lower than at the nominal frequency, the penalty is not so much noticeable in the great scheme of things.
I did this on my MacPro 4.1>5.1 Single Processor, and it didn't work the first time.
In my case, I have an SSD with Windows 11 OCLP (as primary boot) and an NVMe with MacOS Sonoma OCLP (as secondary).
When I made these changes in the NVMe config.plist, the system got stuck on the Apple screen.
In a error attempt, I decided to apply the changes in the SSD config.plist and bingo! It worked perfectly. I have 128GB of RAM (in four 32GB modules).
Since my MacPro only has 4 memory slots, here's what I entered in the config.plist:
Code:
</dict>
<key>Memory</key>
<dict>
<key>DataWidth</key>
<integer>0</integer>
<key>Devices</key>
<array>
<dict>
<key>AssetTag</key>
<string>123456789</string>
<key>BankLocator</key>
<string>BANK 0</string>
<key>DeviceLocator</key>
<string>ChannelA-DIMM0</string>
<key>Manufacturer</key>
<string>Hynix</string>
<key>PartNumber</key>
<string>100-563-491</string>
<key>SerialNumber</key>
<string>80AD01151640E62AB4</string>
<key>Size</key>
<integer>32768</integer>
<key>Speed</key>
<integer>1333</integer>
</dict>
<dict>
<key>AssetTag</key>
<string>123456789</string>
<key>BankLocator</key>
<string>BANK 1</string>
<key>DeviceLocator</key>
<string>ChannelB-DIMM0</string>
<key>Manufacturer</key>
<string>Hynix</string>
<key>PartNumber</key>
<string>100-563-491</string>
<key>SerialNumber</key>
<string>80AD01151640E62AD3</string>
<key>Size</key>
<integer>32768</integer>
<key>Speed</key>
<integer>1333</integer>
</dict>
<dict>
<key>AssetTag</key>
<string>123456789</string>
<key>BankLocator</key>
<string>BANK 2</string>
<key>DeviceLocator</key>
<string>ChannelC-DIMM0</string>
<key>Manufacturer</key>
<string>Hynix</string>
<key>PartNumber</key>
<string>100-563-491</string>
<key>SerialNumber</key>
<string>80AD01150930D7A373</string>
<key>Size</key>
<integer>32768</integer>
<key>Speed</key>
<integer>1333</integer>
</dict>
<dict>
<key>AssetTag</key>
<string>123456789</string>
<key>BankLocator</key>
<string>BANK 3</string>
<key>DeviceLocator</key>
<string>ChannelD-DIMM0</string>
<key>Manufacturer</key>
<string>Hynix</string>
<key>PartNumber</key>
<string>100-563-491</string>
<key>SerialNumber</key>
<string>80AD01150930D7A3A2</string>
<key>Size</key>
<integer>32768</integer>
<key>Speed</key>
<integer>1333</integer>
</dict>My questions are: When I update MacOS or OpenCore to a new version, will I have to redo all this again?
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So this simply means, your machine tried to boot from the (then unedited) OpenCore of your SSD also at the first try.
If you have a GPU showing the native Apple bootpicker by holding Option, you can simply switch between different OC-Versions if you have multiple on your Mac. Each is represented by a Bootvolume named EFI-boot.
Would rather go to three modules. 96 GB are plenty of RAM, but, by populating the fourth slot, you do two bad things:
You loose triple channel, which costs between 10 and 20% of memory performance. And with quad-rank-DIMMs, which the 32 GB modules usually are (shown by "4R" on the label), the real speed drops to 800 MHz, if the 4th socket is populated with an identical module as the other three. The 1333 shown in "About this Mac" are fake / just what you entered in the config.plist.
😎
You can easily check the speed which the RAM is really running using CPU-Z in Windows. Three sticks, running in triple channel, will get you 1066 MHz. And that's all you will get with these 32 GB parts.
If you update OpenCore, yes! The config.plist gets overwritten every time you update OpenCore (i. e. via OCLP). So you have to reenter your edits every time after.
Updates to macOS which do not require an update to OC will leave the config.plist untouched.
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yes absolutely you will. i have the memory mod on my 5,1 also and every update i have to take out the 32gb sticks, re-mod the config list , then put the ram back in. its probably best to set it and not update for a while.
Hmmm, should not be neccessary to re-mod the OC config.plist file for OS updates as long as OpenCore is not updated too.
Also it should not be neccessary to remove any of the RAM sticks. I just re-enter the edits to config.plist after updating OpenCore before i reboot.
you are correct, i must have mis-read something, its all good. if you update OCLP then yes re-mod is needed.
you wont.. i have 128 and it lets my protools run smooth. with 96 i might get an error once in a while. yes it stilll wont use but it works for me.
Hey y'all.. a couple of yrs ago when I was testing the fantastic work of this collective. I was successful in getting 256 installed. It would do the equivlent of bluescreenofdeath, and after firing it up again, it would run a while then do iut again. I decided to take the w2in and live w/ 128GB and finally exceed High Sierra.
. BTW... anyone interested the RAM is available Itis : 8 DIMMS available only in pairs -P256GB 8x32GB - PC3-10600 ECC DDR3L 1333MHz SODIMM RAM - OWC BRANDED w/ Lifetime Warranty
Also have 96GB 16 x DIMMS - PC3 - 10600 ECC-R DDR3 SODIMM 1333MHz
Also have 96GB 16 x DIMMS - PC3 - 10600 ECC-R DDR3 SODIMM 1333MHz
Attachments
Looking to upgrade the ram on my 5,1. I'm not looking to go with 32GB as I don't want to have to keep messing with the config file every time, so 6 or 8x16GB will be fine for me. Will either of the below work?
https://www.amazon.com/Tech-PC3L-10...ddr3l+1333mhz+64gb,electronics,59&sr=1-3&th=1
https://www.amazon.com/OWC-Register...r3+ecc+udimm+64gb,electronics,61&sr=1-20&th=1
https://www.amazon.com/Tech-PC3L-10...ddr3l+1333mhz+64gb,electronics,59&sr=1-3&th=1
https://www.amazon.com/OWC-Register...r3+ecc+udimm+64gb,electronics,61&sr=1-20&th=1
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Count me in with the Danes, learned the hard way by not reading this thread.
I’ll summarize 13 pages for someone else coming in (hope I get this right)
cMP- can totally do way more RAM than advertised (with conditions - fw, certain MacOS versions, opencore config, etc.)
Frequency is less important than type, if you get higher than 10600(1333) it won’t use it (limited by CPU and Northbridge) and will likely use less depending on the configuration in the slots - short answer 6 is better for speed, 8 is better for total density - depends on use case
DO NOT get LRDIMMs or ones that say 10600L or 10600LR these will not POST, if mixed with functional RAM you can boot, but can’t use them. Period.
If however you see the letter L next to “PC3” as in “PC3L” these are fine, that indicates it works in a low voltage set up, not LR - load reduced ( which is all about the way R and L (or LR) buffer, process and talk to the memory controller) long story short THESE are different enough that the system can’t use it, unlike many other attributes of RAM which can work even if not ideal, THIS ONE CANT.
I am learning the hard way, but I know more about RAM than I did before and that’s good too
Thanks a lot for everyone here and all the knowledge being shared! I’m glad to be here!
I’ll summarize 13 pages for someone else coming in (hope I get this right)
cMP- can totally do way more RAM than advertised (with conditions - fw, certain MacOS versions, opencore config, etc.)
Frequency is less important than type, if you get higher than 10600(1333) it won’t use it (limited by CPU and Northbridge) and will likely use less depending on the configuration in the slots - short answer 6 is better for speed, 8 is better for total density - depends on use case
DO NOT get LRDIMMs or ones that say 10600L or 10600LR these will not POST, if mixed with functional RAM you can boot, but can’t use them. Period.
If however you see the letter L next to “PC3” as in “PC3L” these are fine, that indicates it works in a low voltage set up, not LR - load reduced ( which is all about the way R and L (or LR) buffer, process and talk to the memory controller) long story short THESE are different enough that the system can’t use it, unlike many other attributes of RAM which can work even if not ideal, THIS ONE CANT.
I am learning the hard way, but I know more about RAM than I did before and that’s good too
Thanks a lot for everyone here and all the knowledge being shared! I’m glad to be here!
So, to summarise / clarify, to exceed the stated max. RAM (96GB) of a dual-CPU cMP:
- Make sure you're on the latest (?) firmware.
- Configure OpenCore appropriately.
- Use a version of macOS higher than..? Is this still necessary when booting with OC?
- Use all 8 slots (if using 16GB sticks).
- No point using RAM faster than 1333MHz (though faster rated RAM will work, it'll just clock down).
- Don't get RAM that has a designation ending in L or LR i.e. PC3-10600L or PC3-10600LR ("Load Reduced"). They are not compatible and the Mac won't see / use them.
Edits, from info in posts #323, 325:
- Do get RAM with a designation ending in R ("Registered") i.e. PC3-10600R. Such RAM is able to run higher densities (e.g. in 32GB DIMMs). You shouldn't mix Registered with regular U ("Unbuffered") RAM, though - it won’t work.
- RAM that has a designation starting with PC3L i.e. PC3L-10600 is able to run at a lower voltage. The chipset is too old to support reduced-voltage operation, however, so will just run it at regular voltage. So, it is compatible, and may be mixed with regular-voltage RAM, it just won't offer any benefit.
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One thing i did not see or read, and please correct me if i'm wrong, is that, 32 gb dimms will not work unless you alter the configlist, i know because i also learned the hard way. if you leave the dimms in and remove opencore it will not boot.
I don't know - I was just trying to make sense of the previous post. I believe 32GB DIMMs are not possible without using OpenCore.
Why you'd want so much RAM in such an old machine is another matter. If macOS isn't needed, Windows will run 256GB of RAM in a cMP without issue.
its not possible without opencore. Thats all im saying. If you need to know anything else just ask me, im running 2x32 along side 4x16, coincidentily you asked why you would need that much, and i have an answer. To run smoother on protools with zero hiccups. i've had PT since v7 and many years of configurations and macs and the bottom line is? More is always better in my case. if i remove 2x16, ill get a hiccup along the way guarenteed, it wont be a show stopper but it will make an appearance. There you have it my friend.😎
It's not for me; I sold my cMP years ago.
Surely if smooth performance is a priority, a more modern machine would make more sense anyway? Even with a much lower amount of RAM.
Eventually. For the time being i have hardware: Pcie Nvme X2 as well as an UAD OCTO for which i will need a 3 slot enclosure which run about 500 or more, which im not ready to accept because both my 5,1's are fully functional and you know the old saying: if it aint broke dont fix it. BUt yes im resistant to any spending at this time.
Would probably be cheaper to just eBay the PCIe UAD and get a second hand external TB2 version.
Which is a good idea. But now what do I do about my nVME PCIE which are 2 TB each?
Stick them in ~£20 USB-C 3.2 enclosures if 10Gbps is fast enough. Or spend ~£200 on a dual-bay TB3 enclosure if you need the speed.
Personally, I'd probably just sell the NVMe's too, spend ~£200 on a 4TB NVMe and stick it in an ~£90 TB3 enclosure.
Sounds good.Sounds like a plan.I guess that's the way to go.Thank you for your input and perspective.I appreciate you
The low voltage is compatible, from what I can tell the board can’t use the low voltage function so it will operate at its normal voltage.
The big DO get is R for registered as in 10600R without an L. When you say “mixed with regular ram” do you mean U - unbuffered? Because the system will only pick up one kind. In general, not just for this machine mixing ram isn’t the end of the world but it’s not like mixing and matching hard drives. The more uniform the better for RAM, also it’s a weakest link thing. If you have 7 higher frequency sticks and one lower, it will run all 8 at the lower.
Yes definitely have to do that, as the 5,1 will only recognize 16gb sticks unmodified.
As for why? A little Tim Taylor home improvement kinda “because I can and want to” haha
But really as a home server running proxmox for VMs and Jellyfin.
Better to have a really solid ram base to allocate with
P.S. my summation above and obviously needed clarification were me trying to distill all the prior pages and make sure it’s right. It took wading through pages and pages to find the right answers and I just thought it would be good for me to see I had it, and for anyone else to see it all in one place.
What it comes down to is you can't mix UDIMM with RDIMM.
Both RDIMMs and UDIMMs have ECC, the difference is in the bank switching logic and the latency. UDIMMs have lower timings but can support less memory per stick. RDIMMs allow to pack more memory per stick, but rely on a buffer which will slow things down somewhat.
Both RDIMMs and UDIMMs have ECC, the difference is in the bank switching logic and the latency. UDIMMs have lower timings but can support less memory per stick. RDIMMs allow to pack more memory per stick, but rely on a buffer which will slow things down somewhat.