Why is my FCP NOT using much ram?

FCP newbie here, trying to figure out hardware requirements.
 

I have a 2012 Mac Pro six core, with only the stock 4GB ram.   I know I need more ram for various things, and need to order asap, but money is tight & I don't want to waste it.
 
I've read a ton of existing threads, and the only solid answer I could ascertain was "as much as you can afford," and "at least 24 GB."
 
I also understand that more ram helps FCP utilize the video card more efficiently. (via shadow ram?)
 
EXCEPT:
 
yesterday I did my first ever export from FCP.  I was editing 1080p / 10K bit rate clips that were roughly 15 minutes long,  and only loading one at a time. I had changed the perspective, and was "sharing" (Lord how I hate Apple's dumbing down of their apps) without using compressor.
 
To my amazement, my ram usage never went above 1.6 GB.
 
So, the obvious question is:

---

 
What specific FCP scenarios require / benefit from all this "needed" ram that I keep reading about?
 
Bulk rendering of multiple files?
 
redering of hour-long files?
 
Heavy compression?
 

---

Surely, you need enough ram to hold all the files that you are concurrently editing from,  plus any open applications.  And perhaps you needs "shadow ram" to equal whatever your video card has.
 
- But after that, how exactly does MORE ram makes things run faster?  I don't get it.  Yet everyone says, "buy as much as you can afford." 
 
Can anyone give me a real answer?


 
-thanks.

As you edit more and learn more, your projects will become larger and more complex. Then FCP X will eat up much more RAM. It will only use a certain percentage of total RAM, leaving some left over for other apps and the OS to use. It's not loading actual files, as they are read directly from the drive (video/audio data "streams), but the databases and metadata being manipulated at the time.

I've had many of my students report to me that going from 4GB RAM to 8 or 12 significantly increases performance. If FCP X can load the full databases of the projects and events you're currently working on, it will run much more smoothly, more stable, faster.

It's not going to effect exports/transocdes as much, as that's not a RAM based function. I'd never put more than 12-16GB RAM in a system unless you're working on really large projects.

System RAM has nothing to do with Video RAM, they do not interact with each other as such.

Thanks, Ben. You're the only one to take the time on this, and I sure appreciate it.

Still, I'm not clear on certain issues, and disagree (in a sophmoric but respectful way) on others.

Followups, below:

BenB wrote: As you edit more and learn more, your projects will become larger and more complex. Then FCP X will eat up much more RAM. It will only use a certain percentage of total RAM, leaving some left over for other apps and the OS to use.

According to Larry Jordan, FCPX uses all the ram it can find. He has specifically mentioned this is several videos, saying how it's a problem that Apple needs to fix.

-Maybe it's already been fixed? (I'm running 10.0.5)

BenB wrote: It's not loading actual files, as they are read directly from the drive (video/audio data "streams), but the databases and metadata being manipulated at the time..... If FCP X can load the full databases of the projects and events you're currently working on, it will run much more smoothly, more stable, faster.

That makes sense, but then how does one calculate how much ram MIGHT be needed? Or to put it another way: How can I ascertain if, right now, the amount of ram I have is limiting FCP performance? Do I simply look in my "projects" and "events" folders and add up what's in there, being used for a given project?

BenB wrote: It's not going to effect exports/transcodes as much, as that's not a RAM based function.

Huh? everything except the source file is in ram, no? That's how a computer works. I'm really confused. Well, I can see how that might not require MUCH ram.
So what does? Heavy rendering?

If there is a way to further explain this, I think a lot of folks would benefit, as I see tons of posts from people who don't have a clue, just saying "the more, the better." It's like folks thinking that an SSD boot drive will somehow make your applications RUN faster, which is completely false unless you foolishly also keep your data on the boot drive. Yet, the vast majority of users believe this idea.

BenB wrote: System RAM has nothing to do with Video RAM, they do not interact with each other as such.

That's just incorrect.

First, there is something called "shadow ram" that every system uses. It's hard to explain, but your video card needs system ram as a buffer. Of this I am 100% positive. In the Windows world, it needs as much system ram as the Vram on the card. I don't know exactly how it works on a Mac.

Second, it is well documented that having extra ram helps FCP utilize OpenCL, and that of course increases overall performance and lowers the burden on your cpu. The problem is, I can't fins ANY information on how it does this, or exactly how much ram is optimal for this.

I'm hoping to get such answers here.

My guess is that OpenCL is in fact using the shadow ram, shuffling data back & forth between the GPU and the system ram. If so, then I guess you only need about 1 GB of "free" system ram for this. - but I'm completely guessing.

Shadow RAM is a process that allows slow BIOS ROM to utilize system RAM. Macs don't use BIOS. VGA BIOS can utilize Shadow RAM. It helps out slower ROM chips. Shadow RAM usage can also cause problems such as hardware incompatibility. Something Apple has very strict policies against in their hardware designs. Thus, VRAM has nothing to do with system RAM. VGA BIOS can access system RAM in a process called Shadow RAM, which is a non-issue here.

Grand Central allows an app to be multi-core capable.

OpenCL only allows an app to utilize the GPU, which access VRAM, for processing and has absolutely nothing to do with Shadow RAM. Shadow RAM can be used to speedup old, slower VGA BIOS, which is not VRAM.

No, the CPU RAM and VRAM do not interact with each other at all. I'd love to see engineering documentation to the contrary.

FCPX did have a memory leak in it's initial releases, but that's been fixed. A memory leak is when it slowly eats up RAM it's not supposed to access, and does not free it up when no longer needed.

BenB wrote: Shadow RAM is a process that allows slow BIOS ROM to utilize system RAM. Macs don't use BIOS.

Ah, thanks. I didn't know this. However, let me reiterate that the going belief in the Windoze world is to have as much free system ram as your video card has vRam. I both read this, and was told this by a HIGH level Intel tech. That doesn't sound like a BIOS issue, though you do seem to know your stuff. Maybe it's a secondary shadow ram issue? Of course, that tech could have been wrong. It wouldn't be the first time.

Anyway, if we are only talking about 1 GB, it's really a non-issue anyway.

BenB wrote:
No, the CPU RAM and VRAM do not interact with each other at all. I'd love to see engineering documentation to the contrary.

I got that info directly from the Apple website. (I don't have a specific url.) It was also mentioned in some Larry Jordan article. I do have a saved quote from that article:
"Another way that your system will use massive amounts of RAM efficiently is planted in Final Cut Pro Xʼs new hooks into OpenCL processing. Snow Leopard allows applications to make extensive use of your graphics processing unit (GPU) resources using OpenCL. OpenCL will shuttle large amounts of data between your GPU and your main memory, so:
having more memory will optimize your systemʼs ability to effectively utilize as much OpenCL power as possible."

That's a direct quote, and again, I went to the Apple website and found confirmation. I also talked to a low-level (phone support) Apple tech who said he knew of this, but didn't know the details. Heck, I dunno.....

BenB wrote: FCPX did have a memory leak in it's initial releases, but that's been fixed. A memory leak is when it slowly eats up RAM it's not supposed to access, and does not free it up when no longer needed.

Ah, that explains why I'm not seeing it devour my system ram. I found that Jordan article, and it's from 2011, so what you say makes sense:
www.larryjordan.biz/app_bin/wordpress/archives/1623


So then, is there now a setting for how much ram you want FCP to use? I can't find it.

-And thanks again for all of your time.

Shadow RAM is a process that allows slow BIOS ROM of various types to utilize system RAM for faster processing. It's not part of Grand Central.

So.......

Despite Ben's help, I am still completely in the dark. (And I bet I'm not alone.)

Is there any way I will ever understand, under what Specific conditions / tasks, FCP need 48 + GB of ram? Everything I read says that you literally can't have enough.

I'd love to take Ben's advice and just get 12 GB, but I can't add any more after that, (unless I forgo triple-addressing) so I'd be stuck. I'm still running 4 GB, because I don't know what to order.

Can someone explain this in a different way?

I've always heard to have 2GB's for every core..
So if you have 6-core machine then 12 GB's should suffice and FCPX will fly with 12 GB's

I know not a very scientific response but just put 12 GB's in your computer and you'll be very happy with the increased performance.

Interesting.

I don't know how the number can be calculated irrespective of the application used and density of the project, but that number does jive with what Ben suggests.

I'm still not getting a warm fuzzy feeling about this, though.

I have a 12 core and my MP is filled with 64GB ram. Does it help FCPX? Not sure, but I run several apps periodically while FCPX is running such as Photoshop, Logic Pro, Soundtrack, etc.
Occasionally I need to open Motion during an FCPX session and seem to have no problems doing this. I started with 48G ram when I bought the system and just added the extra 16 recently since it's much cheaper now. I definitely notice improvement in the above workflow.

Having gone from 4 gigs to 8 on a MacbookPro, & using FCPX in both situations I can assure you that more ram helps a lot. But how?

Well, one thing this thread hasn't mentioned is render times. You mentioned earlier the size & resolution of the video files you were editing in FCPX, but if hardly any ram was being used, I'd wager you weren't applying many fancy transitions, color grading filters, or effects, which would result in a final video production that appears rather dull & uninspiring.

Also the use of compound clips, various audio tweaks, sound effects, speed ramping, etc, etc, all add interest to the viewer, while burdening the Mac.

Not only do all these processes require ram to playback, or negotiate, they need ram to render. While working on a project under 10 minutes in length & not even HD, the amount of effects & compound clips I'd applied had my 4 gigs of ram (no other programs open) gobbled up right down to a red light warning of under 100 megs. I've had FCPX freeze when conditions get that drastic (though it's rare). I've had to restart the machine to clear our caches. Bumping my ram up to 8 gigs from 4, removed those problems.

If you're going to want to send a clip over into Motion to add some effect & bring it back again, 4 gigs just isn't going to cut the mustard, or any other condiment.

Granted, FCPX has become more stable with each incarnation, yet more ram can never be a bad thing. Sure you want to save money, but when your film piece becomes complex, & your system is struggling, you'll wish you'd spent the money wisely on a bit more ram.

Cableaddict,
Not sure that you are still wondering about RAM, but certain programs including FCPX will use as much ram as is available. Some of the responses give wrong info about how ram is used in FCPX. X does load program, media and all effects into ram. X preloads these as it opens or imports. This is why you can edit on the fly as program is ingesting media or apply effects/edit to project as it plays.
Also ram is used to "push" data to GPU under open CL and to get rendered file back. Open CL offloads video rendering onto your Graphics card so the faster the card is and the more ram on card will yield faster results.
There is a lot more going on that uses ram too. All open programs especially if running in background will use ram as well.
You can see all of this using the built in Activity monitor, terminal and any number of other software programs.
The latest version of FCPX does a better job of ram and open CL and looks to be faster.
Your computer is a triple channel architecture machine, I believe, therefore fill all the ram slots otherwise it will use only dual channels. Poor explanation of dual channel vs three channel, but Mac will default to dual channel depending on ram configuration. Could be wrong about this as I don't own this model mac but I think all 6 and 12 core macs are triple channel. Grand Central Dispatch will push process to all cores, more ram available for each core/processes makes for faster program as OS is not swapping out pages from ram to hard drive/ssd drive.
Lots more could be said but got to go.
Stick in lots of ram, you can't go wrong, pricing is reasonable for the speed boost.
As I said in the other thread, it is total system configuration that makes for the best editing box.
Apple seems to be favoring nVidia at this time and some of their cards are really great. If you use Adobe products, I would definitely recommend looking into one of the Apple supported nVidia cards. You can enable "cuda" for speeding up After Effects and PS. Not sure about what card you have currently. I'm using a ATI6870 in my MP but starting editing on my rMBP.
Here is an old article about FCPX/64bit computing and some other background info you might find helpful. www.postmagazine.com/documents/SilveradoPrepforFCPX.pdf
Lots of other info available including speed tests @, barefeats, digitlloyd, and here in forums.
I agree with Trix on this issue.
Best of luck, Greg

Well, knew I'd screw up the triple/dual architecture of the MP. Shouldn't really talk off the top of my head when I'm in a hurry. Did make me curious though.
Apple does some funny configurations sometimes and limits its hardware. 64bit computers theoretically can handle unbelievable amounts of memory, Apple chooses to limit it. Your computer I think will address 32GB ram?
The Westmere 6 core is a triple channel processor, but Apple only provides 4 ram slots on MoBo/daughterboard. Most triple channel MoBo use paired slots X3 to make the most of bandwidth. Apple's configuration cripples the triple channel by forcing shared channel and when tested there is very little difference in thru put using 3 ram chips vs 4. Having said this, different software apps may still benefit from more GB of Ram using all 4 slots.
As to the original question of why your mac wasn't using all ram on export, ram usage is very dynamic, and software dependent. A well written program will use as much ram as needed and then release it. Early versions of FCPX had release issues, but now seems to be fixed. Wish M$ would fix their POS software, talk about memory hog.
Curious as to file size on final output.
As to links to other articles...
Diglloyd has many related articles here is one on Westmere MP, please note this is over 2 years old, macperformanceguide.com/Reviews-MacProWestmere.html
Here he justifies 96GB, macperformanceguide.com/blog/2012/201207...Photoshop-usage.html
Here's index of a lot of articles, macperformanceguide.com/index_topics.html#MacBookProRetina2012
I like his testing, he has even written some testing apps that he sells. Mostly I find him pretty good.
Didn't you ask about HDD drive performance dropping off as it fills up? Yes indeed Hdd performance does drop, see his graphs, but also seek times go up as well. SSD and flash drives does not suffer this issue. macperformanceguide.com/blog/2012/201210...ce-verification.html
I also like Bare Feats site. Rob does a good job on testing. His site often compares different cards, drives, configurations. Be careful to always check date on testing as technology changes rapidly. www.barefeats.com
Article on ssd's in MP, (year old) www.barefeats.com/ssd6g03.html
As to a definitive answer about how much Ram, Depends on what you are doing. I personally would recommend at least 16GB, but if you got the $$ max out.
Again, you can always transcode to ProRes or Proxy to do editing and then render on export.
Hope this helps, Greg

Well, my head has officially exploded!

Many thanks to all, though I still have no idea what all this will mean to my sessions. (Not that you folks could.)

A few hours before VidGreg posted, I ordered 24 GB ram. The price came way down so I jumped. I could have gotten 48 GB (Greg, I believe my Mac CAN use that much) and I hope I don't need that much because it's too late.

Well, as Greg posted, the Mac's don't properly address triple-channel memory, so evidently there's only about a 10% loss if you add a fourth module, so I have an out. - Except memory managers are usually not happy when all 4 modules are not the same size, so my best option would only be adding another 8 GB.

I guess time will tell.

---

- But here's the important thing everyone should take away from this thread:

it seems that on several critical hardware issues (ram, drive speed, SSD boot drive benefits, etc) most FCP users, even pros, are just fumbling around in the dark. This is kinda' scary, although also somewhat understandable as we are all too busy to do much research, and the info that exists tends to be conflicting.

I've read all of DigiLloyd's articles, but rarely can tell how his findings apply to my setup & sessions. On one issue, I had to email him for clarification. He was nice enough to reply (even added this info to his website) and I then realized that 95% of posters on various forums were dead-wrong about that one issue. (I also confirmed it with an Apple tech)

This is crazy ......

Well, now to re-think the "How fast of a drive do I need?" question. Ughh ....

Anyway, thanks again to you all. Even if the fog isn't completely lifted, this has helped tremendously.