MP 1,1-5,1 cMP & nMP {MacPro 4,1 & 5,1} Memory Upgrade Compatibility and FAQ

[Harry322]

I'm looking to upgrade the RAM on my 4,1 -> 5,1 Mac Pro (Dual 3.0 GHz 6-Core) tower - and with Black Friday upon us, now seems the perfect time.

Currently, I have this configuration : [8/8/8/-] [8/8/8/-] (all 1333 Ghz)

Hoping to upgrade to this: [16/16/16/16] [16/16/16/16]

I want the absolute BEST performance. Regardless of price.

With that in mind, do you have any advice on which brands/retailer to use? I usually get OWC.

And is it worth filling the 4th slot on each bank of RAM? Or is better to stay tri-channel?

Also intrigued by the idea of RDIMMS, which seem cheap. Is this an option? Does RDIMM offer better performance?

 

[flowrider]

^^^^As far as memory suppliers, My Post #2 on this thread:

AFAIK, RAM specifications are the same between a 4,1 and a 5,1 cMP. Especially when the 4,1 is upgraded to 5,1 firmware so the 4,1 can use faster and more cores CPUs.

As for memory suppliers, I avoid eBay and MacSales (OWC) at all costs. Many eBay sellers sell counterfeit equipment and OWCs memory has proven to be suspect.

My RAM supplier since 1986, has been:

https://www.datamemorysystems.com/apple-memory/

They guarantee for Life. They are Mac specialists. In all the years I have been dealing with them, I have never received a bad piece of equipment. I recommend them highly.

IMO, operating on 3 channel is superior as far as speed goes. The CPU is three channel.

Lou

 

[Harry322]

^^^^As far as memory suppliers, My Post #2 on this thread:

IMO, operating on 3 channel is superior as far as speed goes. The CPU is three channel.

Lou

Fantastic. Thanks, Lou. I had figured that 3-channel is preferred but was curious if that was still the case. Any verdict on RDIMMs? They're certainly cheaper, but do they outperform traditional RAM?

 

[h9826790]

Fantastic. Thanks, Lou. I had figured that 3-channel is preferred but was curious if that was still the case. Any verdict on RDIMMs? They're certainly cheaper, but do they outperform traditional RAM?

RDIMM only outperform UDIMM when multiple DIMM share use a single channel. If you stick with 3 DIMM per CPU, AFAIK, RDIMM won’t do better. However, shouldn’t has any noticeable performance penalty as well (if compare to UDIMM).

Also, “best performance” for what? Triple channel only helps if your operation are memory bandwidth limiting for a long duration.

But if your operation can use more than 96GB of memory, triple channel won’t do better than 128GB.

Also, if your operation required repeatedly access some large size data from hard drive. 128GB memeory will able to provide more buffer to serve as cache. Will also speed up the process more.

If cost if not an issue, getting a newer / faster computer with DDR4 will give you much better memory performance.

In any case, OWC is my very last choice of memory.

 

[Harry322]

RDIMM only outperform UDIMM when multiple DIMM share use a single channel. If you stick with 3 DIMM per CPU, AFAIK, RDIMM won’t do better. However, shouldn’t has any noticeable performance penalty as well (if compare to UDIMM).

OK - I think I follow. If I understand correctly, 4 RDIMM sticks per CPU would NOT have a performance penalty on my machine the way that 4 UDIMM sticks would. But you're saying that RDIMM wouldn't necessarily have any noticeable benefits either. Is that right? Or am I still confused?

Also, “best performance” for what? Triple channel only helps if your operation are memory bandwidth limiting for a long duration. But if your operation can use more than 96GB of memory, triple channel won’t do better than 128GB.

Also, if your operation required repeatedly access some large size data from hard drive. 128GB memeory will able to provide more buffer to serve as cache. Will also speed up the process more.

Thanks for clarifying. I mainly use this Mac Pro for video editing. After Effects is the most memory-intensive program I'd be using. I have 48 GB of RAM at the moment and to my knowledge, I haven't ever hit a wall in terms of RAM use. Would I even benefit from 96 GB? 128 GB? I admit that I am not too knowledgeable about these things, so I appreciate the help.

If cost if not an issue, getting a newer / faster computer with DDR4 will give you much better memory performance.

Planning on getting a 7,1 if the price/tech is right. Just trying to squeeze the last bit of performance out of this old cheesegrater...

In any case, OWC is my very last choice of memory.

Noted. Thanks so much for the advice!

 

[h9826790]

OK, time to report back about some 32GB DIMM progress.

One of my German net friend went through a series of test with some Samsung 32GB RDIMM (Part number M393B4G70EMB-CK0). So, all the following credits go to Tobi Jagalski.

It's confirmed the 140.0.0.0.0 firmware can boot with 8x32GB DIMM installed (with dual X5680). The computer will POST, and able to show boot manager.

However, all 10.11, 10.12, 10.13, 10.14 cannot boot with this particular Samsung RDIMM. Either KP, or hang with the loading bar. No matter 1 DIMM to 8 DIMM installed, always the same.

If we mix these 32GB DIMM with some 16GB RDIMM, then macOS will boot successfully, but only the 16GB DIMM will be recognised, and run at 800MHz.

Since the cMP can POST, and boot manager works. And all issues only happen after select macOS. Therefore, the next test is to boot Windows. Mr Jagalski has no valid Win 10 key on hand at this moment (I believe he will get one soon for 256GB RAM test). So, only tested it with Win 7 Pro, which is known to limit to 192GB of RAM. And the cMP actually boot all the way to Win 7 Pro desktop with 8x32GB RDIMM installed, and 192GB of memory recognised (at 800MHz).

So, the compatibility issue is from the OS, not the firmware, or hardware. I also suggested to Tobi that he may try Ubunto 64bit Live CD. So, we may see some data with Linux later.

This M393B4G70EMB-CK0 has different spec than the DIMM that from the known good 5x32GB config tested in Yosemite (M393B4G70BM0).

Another source suggested that we really need DDR3-10600 for this particular scenario to make it work in macOS. However, due to lack of proper hardware on hand. No way to test this theory. But if anyone temped to try 32GB DIMMs, better to avoid DDR3-12800. Even this DIMM is known good to work on the 6,1 (in macOS), it doesn't work in any macOS on the 5,1.

But at least now we know that the firmware is not limited to 160GB memory, and because the cMP can POST and shows boot manager with 8x32 config. Most likely it means our cMP can actually run 256GB RAM as long as we get the correct DIMM, and if the OS itself support that config.

In terms of speed. If install all 8 DIMM, memory runs at 800MHz. But if only install 6 DIMM, then memory runs at 1066MHz. It's very typical when using "wrong" memory rank DIMM. Since there is no 2Rx4 32GB DIMM available. We can only use 4Rx4 to do the test, and this "downclock issue" is somehow expected.

 

[h9826790]

Windows 10 test done. As expected, all 256GB RAM usable. Running at 800MHz.

So, it's now 100% sure the Mac Pro 5,1 can work with 256GB of RAM. All we need just the correct DIMM and a supported OS.

A little bit sad that Windows working better on a Mac than macOS (again).

 

[LightBulbFun]

iv been following this elsewhere and its very cool to see it finally come to ahead and see 256GB of RAM in a MP5,1

but I do have a few questions

any chance for a CPU Z validation?

as for OS X Kernel panicking/getting stuck can you please post a Kernel panic log/verbose boot screen picture so I can read it and see what OS X is kernel panicking on/getting stock on? I suspect AppleTyMCEDriver.kext may be the cause of the Kernel panic AFAIK its a kext to do with ECC RAM on the MP4,1/5,1 and XS3,1

also on the 5x 32GB + 1x 16GB did you check specifically under terminal with the hostinfo command and the memory tab of activity monitor how much RAM was actually available to the kernel/system?

keep in mind 32GB RDIMMs dont show up in System profiler at all for some reason.

and is the "Diagonstics" tab in system profiler reporting anything?

 

[h9826790]

iv been following this elsewhere and its very cool to see it finally come to ahead and see 256GB of RAM in a MP5,1

but I do have a few questions

any chance for a CPU Z validation?

as for OS X Kernel panicking/getting stuck can you please post a Kernel panic log/verbose boot screen picture so I can read it and see what OS X is kernel panicking on/getting stock on? I suspect AppleTyMCEDriver.kext may be the cause of the Kernel panic AFAIK its a kext to do with ECC RAM on the MP4,1/5,1 and XS3,1

also on the 5x 32GB + 1x 16GB did you check specifically under terminal with the hostinfo command and the memory tab of activity monitor how much RAM was actually available to the kernel/system?

keep in mind 32GB RDIMMs dont show up in System profiler at all for some reason.

and is the "Diagonstics" tab in system profiler reporting anything?

Already show your post to Tobi, he is interested in it. And most likely can provide the info you want.

 

[LightBulbFun]

since now we know 32GBx8=256GB will POST and boot windows etc

I wonder if its worth submitting a bug report to apple about it

 

[h9826790]

CPU-Z cvf file attached.
[doublepost=1544136481][/doublepost]

since now we know 32GBx8=256GB will POST and boot windows etc

I wonder if its worth submitting a bug report to apple about it

We should, and most likely the very first reply will be "when it happen, press Command + Option + Shift + Control + . to obtain a sysdiagnoses......" despite we told them we can't even boot to desktop
[doublepost=1544139609][/doublepost]And here is the KP in verbose mode.

 

[LightBulbFun]

Hmm thats a pretty short KP guessing it happens early on in the boot process?(can he try booting SL 10.6.8?)

there was 1 person here who got 1 32GB DIMM somehow and tested it in a 5,1 where it worked, we need to find out what that one was.

(BTW he is meant to submit the CPU-Z validation file and generate a validation link like so for example: http://valid.x86.fr/yfi38v ) and as for it running at 800Mhz, try pulling DIMMs 4 and 8 so your in a 1DPC 192GB configuration then I think your speed should go up to 1066Mhz at least

im also wondering what Apple Service diagnostics might make of the 256GB. (even if the OS X part wont boot i wonder if the EFI part will)

also wonder if this will work in an Xserve3,1?

 

[h9826790]

Hmm thats a pretty short KP guessing it happens early on in the boot process?(can he try booting SL 10.6.8?)

there was 1 person here who got 1 32GB DIMM somehow and tested it in a 5,1 where it worked, we need to find out what that one was.

(BTW he is meant to submit the CPU-Z validation file and generate a validation link like so for example: http://valid.x86.fr/yfi38v ) and as for it running at 800Mhz, try pulling DIMMs 4 and 8 so your in a 1DPC 192GB configuration then I think your speed should go up to 1066Mhz at least

im also wondering what Apple Service diagnostics might make of the 256GB. (even if the OS X part wont boot i wonder if the EFI part will)

also wonder if this will work in an Xserve3,1?

Oh, you mean this link?

https://valid.x86.fr/3h9hbl?fbclid=IwAR0-jDOOQ8jtib0wNVMVLVCkInJ3eOhEANPa9dMiBUqVX14qmcxHvYFTbw8

Yes, it's confirmed the RAM will run at 1066MHz if only install 6 of them (192GB).

And no, never try 10.6.8. The one that can boot 160GB RAM is Yosemite.

 

[LightBulbFun]

Oh, you mean this link?

https://valid.x86.fr/3h9hbl?fbclid=IwAR0-jDOOQ8jtib0wNVMVLVCkInJ3eOhEANPa9dMiBUqVX14qmcxHvYFTbw8

Yes, it's confirmed the RAM will run at 1066MHz if only install 6 of them (192GB).

And no, never try 10.6.8. The one that can boot 160GB RAM is Yosemite.

thanks for the validation link im curious about 10.6.8 just to see if it boots or not (even tho 10.6.8 can only address 96GB)

yeah we know the RAM sticks the 160GB guy used, but there was also a guy who bought 1 32GB stick to try in his MP5,1 where OS X did boot, so that would be another model of 32GB RDIMM to try 8 of I do find it very interesting how OS X kernel panics with 1 type but not the other.

now we need someone to try some 64GB LRDIMMs

BTW just had a thought, how big is the OS X Boot volume?

its not something silly like OS X trying to create a swap file bigger then the boot driver and falling over is it?

 

[h9826790]

its not something silly like OS X trying to create a swap file bigger then the boot driver and falling over is it?

Ar... never think about that, but totally possible.

I am not sure if Tobi use 250GB or 500GB SSD as the boot drive.

But if the OS try to create a 256GB swap "reserve", that may cause trouble even on the 500GB drive.

 

[LightBulbFun]

Just realised if OS X Kernel panics with even 1 of those 32GB Sticks then its prolly not a swap file issue :/

I found the guy with the 1 32GB RAM stick https://forums.macrumors.com/thread...-cmp-anyone-tried-this.2046693/#post-24946784

sadly he does not mention exactly what RAM stick he bought other then its a Hynix one

 

[h9826790]

Just realised if OS X Kernel panics with even 1 of those 32GB Sticks then its prolly not a swap file issue :/

I found the guy with the 1 32GB RAM stick https://forums.macrumors.com/thread...-cmp-anyone-tried-this.2046693/#post-24946784

sadly he does not mention exactly what RAM stick he bought other then its a Hynix one

Don't know, I was actually looking forward his post about single processor + 32GB DIMM, but seems no follow up.

Anyway, if I were him, I will get this one. The cheapest Hynix 32GB 4Rx4 PC3L-10600R ECC stick I can found in China online store. ($64 each)

 

[eksu]

On windows, can we get an idea of the performance delta between performance (single threaded and otherwise) with 1333mhz memory and 1066mhz memory?

 

[h9826790]

On windows, can we get an idea of the performance delta between performance (single threaded and otherwise) with 1333mhz memory and 1066mhz memory?

You mean pure memory performance? Or overall system performance?

 

[eksu]

Benchmarks I would be interested in would by some sort of synthetic benchmark, geekbench for example, or a memory-speed sensitive game, say Fallout 4. I realize that is a pretty niche use case for the Mac Pro. Anything that would quantify the difference would be of interest to me and I think others.

I just ordered my 96GB Kit (went with Samsung YK0 dimms, they were the same cost as YH9). I plan on using my Mac Pro for virtualization eventually. I think I'm happy with where I'm at given the $/gb for higher quantities and the loss of memory speed.

 

[Macschrauber]

Don't know, I was actually looking forward his post about single processor + 32GB DIMM, but seems no follow up.

Anyway, if I were him, I will get this one. The cheapest Hynix 32GB 4Rx4 PC3L-10600R ECC stick I can found in China online store. ($64 each)
View attachment 809225

Those are Low Voltage sticks. Do they provide double voltage mode ? How hot will they get with high voltage ?

 

[h9826790]

Those are Low Voltage sticks. Do they provide double voltage mode ? How hot will they get with high voltage ?

All PC3L has backward compatibility, and will run at 1.5V in cMP.

 

[Macschrauber]

Yes, but as the design is for 1.3 Volt they should drop the voltage, and so I guess this causes more heat. Compared to native 1.5 Volt sticks. So sooner throttling. Just my imagination...

 

[h9826790]

Yes, but as the design is for 1.3 Volt they should drop the voltage, and so I guess this causes more heat. Compared to native 1.5 Volt sticks. So sooner throttling. Just my imagination...

My understanding.

When operate at 1.3V should generate less heat than 1.5V.

And when operate at 1.5V, should generate the same heat as normal 1.5V DIMM. Shouldn't throttle earlier.
[doublepost=1544477184][/doublepost]It's confirmed the 5,1 can also boot 256GB RAM in Linux.

So, only macOS doesn't work on that testing machine. Possible due to firmware issue (which only affect the macOS boot sequence).

 

[eksu]

On the topic of 1.3v memory, is it possible to change the voltage through nvram variables, or do you have to modify the nvram portion of the firmware?