Ram Upgrade on Mac Pro 2019 for 96khz

[Paulienat]

Hi,

as a composer I'm using many virtual instruments and heavy sample libraries on 96khz sessions, like Spitfire, Keyscape etc...so it happens that I use all the 48gb of Ram on a Mac Pro 2019 12 core.

I've also noticed better ram performances on Ableton Live, looks like PT on this combination of processor and Ram is more cpu/ram demanding.

And obviously at 48khz it takes half the amount of Ram on the same session.

Anyway I want to upgrade the Ram filling all the 6 modules left available.

I can add 48gb (8gbX6) with a total of 96gb or (double the price) add 96gb for a total of 144gb, but I have the feeling that 144 gb is an overkill because of the cpu performance limits that probably I would hit in any case.

Any feedback out there?

Thanks

[Darryl Ramm]

Unclear exactly what DIMMs you have installed now. Or if you are looking at exactly the same make/model DIMMs. You maximize performance when you populate each memory channel equally and reduce risk of problems by matching exact make/model/part number across all DIMMs.

Originally Posted by Paulienat

And obviously at 48khz it takes half the amount of Ram on the same session.

I am not sure these is a simple relationship between sample rate and memory usage.

You might be low on memory, but how are you determining this? Does Activity Monitor showing memory pressure happening? What problems are you seeing? Looking at memory used/free can give an unrealistic idea about memory use as apps will just tend to bloat, consume lots of memory until put under some memory pressure.

Have you looked at major uses of memory? What is disk cache set to? How full (look at the disk cache meter) does it ever get? Are all the VI samples streaming? Any have tunable memory cache/buffer settings? Any non-streaming VIs with large memory buffers/servers? Things like web browsers running? Chrome can eat GBs of memory.

I doubt anybody here can guess what you are doing--enough to then recommend how much memory you should buy. Or have any useful feel for when that might become CPU bound? But you can maybe start by making sure you are looking at memory use of your system as best you can.

[uptheoctave]

I can't recommend what you do, besides putting in as much RAM as you can justify, although the 2019 Mac Pro can take so much RAM that you will reach a point of diminishing returns.

I upgraded from 160GB to 256GB recently and I did notice a small performance improvement but that is probably because I was mixing 8GB DIMMS (Apple) with 32GB DIMMS (OWC).

I may well have had better performance just having 128GB of RAM using only the OWC DIMMS. At some point I should benchmark this. If I do I will report back.

[Paulienat]

Originally Posted by uptheoctave

I can't recommend what you do, besides putting in as much RAM as you can justify, although the 2019 Mac Pro can take so much RAM that you will reach a point of diminishing returns.

I upgraded from 160GB to 256GB recently and I did notice a small performance improvement but that is probably because I was mixing 8GB DIMMS (Apple) with 32GB DIMMS (OWC).

I may well have had better performance just having 128GB of RAM using only the OWC DIMMS. At some point I should benchmark this. If I do I will report back.

Nice to hear from a Mac Pro 2019 users

Do you think is because of the mix of two different sizes of Ram Modules on the same pair or for for having two different manufacturers, OWC + APPLE?

In my case I'm going to have 6 gb APPLE + 6 gb OWC, all of the same size (8gb), for a total of 96 gb.

[uptheoctave]

Originally Posted by Paulienat

Nice to hear from a Mac Pro 2019 users

Do you think is because of the mix of two different sizes of Ram Modules on the same pair or for for having two different manufacturers, OWC + APPLE?

In my case I'm going to have 6 gb APPLE + 6 gb OWC, all of the same size (8gb), for a total of 96 gb.

Well, Apple say 'Use the same size memory modules across all slots to maximize performance.'

Others have reported issues mixing RAM brands, although I am not sure if that is true.
Someone else might be able to comment.

I actually have 6x Apple DIMMS in 8GB each that I'd do at a decent price for you.
They came out of my system- bought with the machine, I was one of the early adopters (first outside Avid and Apple to have a working HDX system I think) so the OWC RAM wasn't available when I bought the machine.
I'm in the UK.

But for myself, I didn't go down adding more 8GB DIMMS once the larger ones were available.
32GB is the sweet spot- OWC do them for $270 a pair of $530 for four.
Leaves room to expand down the line.

[Paulienat]

Originally Posted by Darryl Ramm

Unclear exactly what DIMMs you have installed now. Or if you are looking at exactly the same make/model DIMMs. You maximize performance when you populate each memory channel equally and reduce risk of problems by matching exact make/model/part number across all DIMMs.



I am not sure these is a simple relationship between sample rate and memory usage.

You might be low on memory, but how are you determining this? Does Activity Monitor showing memory pressure happening? What problems are you seeing? Looking at memory used/free can give an unrealistic idea about memory use as apps will just tend to bloat, consume lots of memory until put under some memory pressure.

Have you looked at major uses of memory? What is disk cache set to? How full (look at the disk cache meter) does it ever get? Are all the VI samples streaming? Any have tunable memory cache/buffer settings? Any non-streaming VIs with large memory buffers/servers? Things like web browsers running? Chrome can eat GBs of memory.

I doubt anybody here can guess what you are doing--enough to then recommend how much memory you should buy. Or have any useful feel for when that might become CPU bound? But you can maybe start by making sure you are looking at memory use of your system as best you can.

You're absolutely right, I understand.

My setup is a fast external SSD just for libraries and another, same type, dedicated external SSD for the sessions (both 1000 mb/s). Plus the internal 1 Tb SSD (around 4000 mb/s) for the system and software. UAD Apollo Rack Multi-Cascade TB2 setup. Protools Studio. Avid S1 2 units system.

I check the Ram usage both from Protools Meter and Activity Monitor. No background app excpet for the UAD Console and some random Safari browsing that, in my case, don't affect the Ram monitoring percentages.

But I think it would be too tricky to go into more details.

I think I asked the wrong question:

I'm curious about the RAM/CPU balance that other PT users have found in their workflow, especially on a Mac Pro 2019, while working with big Virtual Instruments / Sample Libraries. If anybody has a similar setup.

[Darryl Ramm]

Originally Posted by Paulienat

I check the Ram usage both from Protools Meter and Activity Monitor. No background app excpet for the UAD Console and some random Safari browsing that, in my case, don't affect the Ram monitoring percentages.

But what numbers are you looking at, again memory used and free metrics may not be telling you what you think they are. The system is not actually low on memory unless you see the memory pressure graph come out of the green. Is it? Are you getting memory or CPU errors? Stuttering, other VI problems? Adding memory will not hurt, more memory is great, but I am not hearing for sure if you really need to do this.

[The Weed]

As an aside, would Vienna Ensemble Pro solve any of the OP's issues?

[Darryl Ramm]

I also posted some other comments on memory usage recently. https://duc.avid.com/showpost.php?p=...0&postcount=15

Maybe most useful there is mention of boot-args="maxmem=xx" and the memory_pressure utility that can help show how much more memory you have than might be needed to just do the job. If you suspect you are low on memory, deconfiguring say 8GB or 16GB and just see what happens can be useful. May or may not be helpful here, but might help others.

The complexity with VIs is not only is the DAW causing memory use and the operating system potentially then reducing then amount of physical memory actually used but the VIs are also managing memory, how much they allocate to memory resident sample caches or streaming buffers. Some may be configurable, some may be configured by the software based on systems configs, I'd expect some might change themselves if the system is running low on memory.

[Paulienat]

I just installed 6x8gb Owc Ram Modules in the Mac Pro 2019 and I found out this:

I had 6 Apple 8gb original modules installed in slot 1-3-5-7-9-11 so, based on the knowledge that I had about the Hexa mode and how they share the channels I've left the original modules in their position and I just add the Owc modules in the free slots, 2-4-6-8-10-12.

When I turned on the Mac I had the orange light telling me there was a problem with Ram. So I checked again every module and reset. Same problem again.

Then I put all the modules in pairs so, Apple 1-2-3-4-5-6 and OWC 7-8-9-10-11-12. And it worked.

Apple tells you how to put different modules in the best sequence to optimize performances but they don't tell you how to integrate Apple-approved modules in the slots, except for the suggestion of not mixing different sizes and R-dimm with LR-Dimm