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FCP Rendering CPU Usage
Hi Guys,
Apologies of there is a simple answer to this that I am unaware of.
I have a new 8 core Mac Pro and am currently editing a project in FCP 6.0.2 with mixed DV and HDV source material (mostly DV, delivery as DV).
I have DV sequences with render control set to Pro Res to render the HDV bits down as and when I want to. Now aside from the well discussed issues about the ways to work with HDV and DV, I actually want to know this…
Although the rendering I’m doing isn’t completely horrific, it seems to often be about 1:1 ratio of time of clip to time to render (so if I’m going to render a minutes worth of footage, it’ll take a minute to render).
A quick look at activity monitor reveals that my machine only appears to be using 35% of my CPU (according to activity monitor) to do this, leaving the rest idle (I am running nothing else in the background other than the OS). Surely this new machine should be using a lot more of it’s available power than that for all these bits of rendering?
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13 Replies
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The 35% of eight CPUs means that you have almost 3 CPUs working at 100%. Not too bad.
I guess there are certain processes that must be done in a sequential way. Others must be done in parallel. Compressor can make work the eight processor at the same time.PPC G5 2x2Gh 4GbRAM/BlackMagic SD/PMBP 17″Core2Duo 4GbRAM
JVC DTV-17″/FCS2/AE CS3/COMBUSTION/SHAKE -
I can’t say for certain in your case, Finn, but usually this kind of thing means that your computer is much faster than your hard drives. It can only work as fast as it’s given data.
I notice this on my Mac Pro too. The stuff I have on my internal SATA RAID renders faster than old projects I still have on firewire400 drives.
This has always been true, but we didn’t notice it as much when computers were slower. The faster the processors get, the more obvious this effect is.
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Both good points, thanks.
It’s not really slowing me down or anything, and obviously the unrendered HDV in a DV timeline plays real time anyway. Just seemed an odd thing not to be able to use all 8 cores fully, especially when I have a hugely optimistic and naive idea about just how fast this machine should be. In my opinion, it should so fast and impressive that it edits the thing for me before I’ve even shot it.
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FCP isn’t coded to take advantage of all those cores. Awesome, huh?
So while you render away you can have Photoshop running, itunes playing, and browsing the Cow without any performance hit to FCP.
Only a few programs right now can use 8 cores: Shake, Compressor, After Effects
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This is wrong. FCP is coded horrifically for rendering. On my machine, if Activity monitor says 35%, it’s 35% of ONE cpu. If it’s using all 4 to capacity it says 400%. (Quad 3.0)
If you think about it for a second, you’ll realize there’s no way drives are the bottleneck, unless you’re compositing many layers of uncompressed data.
DVCPRO HD, for example clocks in at 15-18 MB/sec– modern single drives have sustained throughput of 3-4 times this– yes it gets bigger once uncompressed, but this happens in memory & cpu– the drive is not the bottleneck here.
I’ve done the math many times on my timelines re: datarate of source material, and there’s no way drives are the bottleneck.
FCP is inefficiently written, renderwise. Once you fall out of the RT capabilities, they haven’t bothered to optimize it for multithreading, which is pretty inexcusable, considering how many generations of CPUs are multithreaded.
They didn’t bother before with G5s because of memory bandwith– the actual pipe going from bus to the memory to CPU was slow and tight– That’s why Avid Adrenaline on PCs kicked G5s to the curb– sure, the G5 could run a mean specint, but if you can’t get the data to the CPU, what’s the point– and if the developers were running up against a bottleneck, why bother making your cpu code efficient..
And now we’re paying the price. For the first time in a long time, the biggest limiting factor is not the hardware, but the bad code.
And they’ve taken their bad practices to Motion as well– Just throw the stuff to the GPU and let it handle it, then come up with some lackluster code for when you exceed the GPU capabilities. Aftereffects absolutely destroys motion on basic, basic things like moving text. How can you screw that up? Plus, layer a few effects or put a dozen instances of a (seemingly simple) motion template on the timeline, and the system slows to a deathcrawl… I hope Final Cut studio 3 is just final cut studio 2 that actually works well. (That includes a sane media manager)
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Here Here!
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I’ve realized that too. Final Cut code don’t support all those cores.
Since the first post is from a long time, any news on that? Anybody???Thanks a lot guys, love this forum. Always, I ALWAYS find what I’m looking for, down here….
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[Andre Machado] “Since the first post is from a long time, any news on that? Anybody??? “
What we’ve been pretty much saying for about 2 years now. It will require a complete re-write of FCP to take advantage of the new architecture. Snow Leopard comes out in September. Maybe a new FCP will come out after that.
With Apple, there’s only one thing for certain. A newer and faster iPhone will be released within about 6 months.
Walter Biscardi, Jr.
Biscardi Creative Media
HD and SD Production for Broadcast and Independent Productions.STOP STARING AND START GRADING WITH APPLE COLOR Apple Color Training DVD available now!
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[walter biscardi] “Snow Leopard comes out in September. Maybe a new FCP will come out after that.
…A newer and faster iPhone will be released within about 6 months. “
Hi
There appear to be substantiated indications that a new FCP may come before that, which would mean Leopard-compatible (= more of the same old thing). So the light at the end of the tunnel everybody is waiting for could be FCS 4, due maybe 18+ months after Snow Leopard…On the bright side, the iPhone can’t exist will all that kludged code that Cory wrote about 🙂
So that will be the motivator for the full rewrite of QuickTime thats begun with QuickTime X player.(Media Manager can’t be fixed without QT’s metadata structures being ‘fixed’ – thats my guess).
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Hi, all. Sorry for my bad English.
I have 8 Core MAC (Two 2.26GHz Quad-Core Intel Xeon “Nehalem” processors, 12Gb RAM), Snow Leopard and Final Cut Studio 3. When I am trying to render anything , activity monitor shows me that used only one CPU of 16! Im little bit tired of it.What I have to do to use 2, 3, 4 CPU or even more for rendering one project? Is there any patches, settings, updates, additional software?
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