FS7: XAVC-I Brings Even the Mighty i7-4770 to its Knees

basspig

basspig

Veteran
Today, my friend and associate brought over the new 'super PC' that I built for him, for some training on Premiere CC 2015.

This system has 32GB RAM, an i7-4770 CPU at 4GHz and a GTX680 GPU, plus all drives are SSD's.

It easily handled 4 camera angles of AVCHD footage from his various Panasonic DSLRs, but 5 and more was too much. He had a small orchestra shoot with 7 cameras that he was trying to edit with multicamera.

After all of that was done, I brought over some of my 4K footage from the FS7 and we played it back. One clip, after an initial stutter at start of playback, seemed to play smoothly for the rest of the clip. Then we tried to edit four camera angles in multicam. That didn't work out well. It played four cameras about as well as my 8 year old NLE plays one XAVC 4K stream. So we backed it down, finally to 2 streams. At 2 streams, it dropped 26 frames in 20 seconds of play.

I fired up Task Manager to see what the CPU load was. It was pegged at 100% for 2 streams. Then we tested one stream. That was about 40% CPU utilization.

Since he's not doing 4K work, it's not an issue for him, but it makes me feel better about spending so much money on a dual CPU monster that supports dual 18-core CPUs and 1TB RAM, plus an nVidia Titan X with 12GB VRAM.

Looking at Intel's specs for the chips, the memory bandwidth of the i7 is less than half that of the E5 Xeon processor, so I think that alone should help a lot. I am hoping that it will be able to handle four 4K XAVC streams, as I anticipate a total switchover to 4K in 2 years.

What I learned from this test is that XAVC takes an extreme amount of processing power (at least that's the case with Adobe Premiere CC 2015 with the update that was released 3 days ago).

I should be able to make some comparisons real soon. UPS and Fedex tracking numbers show that the parts should be here on Wednesday. Assembly will begin in earnest tonight, and perhaps software / OS installation on Thursday.
 
Can't you just decode in 1/2 or 1/4 res in premiere if you need better performance?
 
Just wondering, is the Mercury Playback Engine hardware acceleration definitely on?

I've had Adobe apps crash before and then turn off the Mercury hardware acceleration on restart (without me noticing), leaving the processor to do everything. Really obvious slowdown for some things on my laptop, but might be less apparent with a more powerful desktop - until you turn to a really demanding codec,

Ben
 
Is the harddrives adequate?

I had troubles until i upgraded to a RAID 5 array, with a proper RAID PCI-E card to run it all.

My next computer has a thunderbolt adapter with external raids attached :-)
 
Editing 4K is all about fast storage and no bus bottlenecks.

If you want to a great experience editing 4K then get some PCIe attached Flash storage it gets round the potential bottleneck from the SATA controller.

I very much doubt the CPU is being brought to its knees my Macbook Pro edits 4k like a hot knife through butter.

Isn't this the bloke who keeps having to re-wrap the files to edit in a dated version of Premiere? So why not just transcode to another codec or do as others have suggested and engage a proxy workflow?

You can lead a horse to water.....
 
Nirv said:
Editing 4K is all about fast storage and no bus bottlenecks.

If you want to a great experience editing 4K then get some PCIe attached Flash storage it gets round the potential bottleneck from the SATA controller.

I very much doubt the CPU is being brought to its knees my Macbook Pro edits 4k like a hot knife through butter.
Click to expand...

Editing 4k is not just about fast storage unless you are editing 4k uncompressed... Decoding compressed images certainly requires CPU power, and if the CPU is at 100% load then yes the CPU probably is a bottleneck. What format of 4k are you editing on your macbook pro? I have the same quad core haswell i7 CPU as a macbookpro in my windows laptop and it definitely has trouble handling 4k ProRes LT at full res and works much better at 1/2 res.


Also mercury playback engine only accelerates optimized effects, not decoding. CPU handles all decoding no matter whether you are in software, CUDA or OpenCL mode.
 
I run 4k XAVC-I on my old i7 2600K a bit overclocked without any problems. This is a PC i bought in 2012 and when I started to edit 4k this year I had to make a few improvements. First I had a GTX560TI GPU card. This card worked fine for full HD but 4k wasn't that great. I put in a GTX970 card and it now runs smooth. You have to have a GPU card with at least 4GB of V-RAM. More importantly is to have all media and the media cache set to the same drive in PP. This will make it run smooth.
 
nyvz said:
What format of 4k are you editing on your macbook pro? I have the same quad core haswell i7 CPU as a macbookpro in my windows laptop and it definitely has trouble handling 4k ProRes LT at full res and works much better at 1/2 res.
Click to expand...

I'm editing 4k XAVC-I like it's DV. It couldn't be easier.
 
I think it has a lot to do with how well the graphics card is dealing with an incoming 4K sized uncompressed raster from the CPU, resizing it, and getting it to the GUI. Remember, a 4K rescale even to display on a 1080-ish or 2560-sh GUI is no small feat.

At any rate, Apple has this wrapped up. I don't mean to start a platform discussion, but I was testing in December 2012 4K XAVC from the F55 (thanks to Ned Soltz) before I got mine on a late 2011 i7 iMac with GTX680MX graphics (and 24GB of RAM), and it was like butter. As somebody else said above, like DV from 2003. I was braced for F55 4K XAVC not to work on it well, but it was beautiful. Multicam was fine on it too.

[edit: I just checked Craigslist and you can get the same i7 iMac with same gfx for $1500]
 
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OP: What do you mean by 4 camera angles?

Is this 4 pictures in 1 picture? (Aka 4 streams simultaneously?)
Or is this just 4 different angles edited together linearly, like, angle 1 5 seconds, then angle 2 1 seconds, angle 3 3 seconds etc.?

Ive never had any trouble editing on my i7 4790K, which is just barely better than the i7 4770. I only have 16gb of ram and GTX 670 SLI in this rig too. I use this rig for testing purposes only, as i mainly use it for entertainment.

My main editing rig is an i7 3930K with 64gb ram, RAID 5 array, dedicated RAID card, SSDs in RAID 0 for OS disk, ATI r9 290x card for video editing, and watercooling over the block.

Both computer are running on native 4K UHD NEC monitors. I have edited and delivered several 4K Prores HQ projects on the 3930K rig, and tested alot of minor edits on the 4790K rig, and never had any hangups. I always edit on Premiere Pro with maximum bit depth, and with 1/1 quality as long as i dont do any grading or effects work.

It has worked flawlessly.
 
I bumped the resolution down to 1/8, but it was still jerky as heck, barely any better. That only helps if your GPU is the bottleneck, but the CPU is. Anyway, this was academic, as it's my friend's system and he edits GH-2 footage, not 4K. My test with FS7 footage was to give me an idea of the limitations of the i7. Could be Premiere CC 2015 is really piggish and sluggish, too. Another NLE may run better.
i7 is adequate for ONE stream of XAVC 4K. 2 with frames dropped. But more than that in multicam is a fantasy.

Compressed footage won't max out an SSD.

I'm building a dual Xeon system for myself. All the parts arrived today, but the EVGA Gold 1000W power supply's 24-pin cable is 5" too short to reach the motherboard connector.. and they brag about how it's built to power dual CPU boards. I'll have to route it OVER the CPUs instead of neatly in the chassis cable runways. But in two days, I should have a system up and running. I'm hoping dual 18-core CPUs and 1TB RAM and a Titan X with 12GB will make editing four 4K streams go smoothly.
 
this is not a mac vs pc thing....but it is very important to understand that there is so much more to all this then just getting the biggest baddest part squeezed into one box....todays OS (s) and aps are so fine tuned that a super computer might be upstaged by a portable with a certain codec/workflow/app....a huge part of all this is how the parts communicate....one OS or app update can throw a custom box completely off while the same one might double the speed of a consumer box....
identify the camera/ files you are working with, identify the NLE or apps, get the right machine for that combination....
i honestly don't think custom boxes or mackintosh are worth the hassle....
 
basspig said:
My test with FS7 footage was to give me an idea of the limitations of the i7. Could be Premiere CC 2015 is really piggish and sluggish, too. Another NLE may run better.
i7 is adequate for ONE stream of XAVC 4K. 2 with frames dropped.
Click to expand...

Premiere CC is not piggish. That's kinda what I'm trying to say.

I think if you got a current GPU and made sure Premiere was using CC, you'd be in markedly better shape.

BTW, if reducing viewer resolution in Premiere is speeding things up, then it points to GPU. With XAVC decoding a frame is all or nothing on the CPU. If the bottleneck is just how much of that frame (full vs 1/2) is getting pushed to viewport, then it implicates scaling capabilities/capacity on GPU

Paul schefz said:
this is not a mac vs pc thing....but it is very important to understand that there is so much more to all this then just getting the biggest baddest part squeezed into one box....
Click to expand...

Very much agree. I think OP will get his machine doing what he needs better, there's just a few things to look into.
 
It is definitely not GPU issue, as reducing the monitoring resolution makes barely discernable, if any, difference.
Just looking at Taskman tells the story. 100% CPU utilized with two streams in multiple camera mode.

I am done assembling the workstation in terms of physical parts. Next comes the great "on turning", followed by BIOS setup and OS installation. I should finally have enough system to allow. AE and PR to both be open concurrently.

New motherboards don't have mouse or keyboard ports... I''ll need to hit Staples for a USB mouse so I can run setup.
 
Couple of things here.

First off GTX680 is not sufficient for the 4K stream. I had to update to the GTX980 for improved memory bandwidth and I am running an early i7 - 970 Hex (24GB RAM 1800) and it's fine with all versions of XAVC from the FS7.
Second, there have been significant issues with the CC 2015 roll out. One problem is memory leakage (Lumetri Scopes) and other issues. An update has been issued, but users are still complaining of poor playback. I suggest you pay a visit to the Adobe Prem Pro help forums. I rolled back to CC2014 and have no problems in 4K, but I have problems with CC2015. I hope also you've not installed Windows 10.

Do what some do and wait at least 6 months before piling into new versions of software.

The other issue can be I/O bottlenecking in the drives - my scratch are 4 x WD Blacks in RAID 0 array (SATA II even). Again, no problem with 4K playback. No doubt I could get better throughput if I used SATA III, although I note you mention SSD. So clearly, there is a problem.

If you, as you say. built this for your friend with the GTX680 then you've under specc'd it for 4K. This has nothing to do with the XAVC-I codec.

Claire
 
I find the GTX680 perfectly adequate for UHD Prores on my quad core from 2007. So I recommended it to my friend when we specked out his new system. His old system couldn't handle 4 streams of HD from his Panny GH2. The new system works well for HD multicam.

But we're seeing XAVC 4K nailing the CPU usage to 100% for two streams.

I'm following the CC fiasco on Adobe forums, and I've cited it as another reason why I myself don't move off of CS6. But my friend already has a subscription for CC and he's got 2015 in there with the July 27 update. If it were me, I'd be on CS6, as he has no need to edit XAVC at the moment.

All his drives are fast SSD drives. No bottleneck there.

If the 680 isn't enough, then wouldn't it have trouble playing prores 4K? We're seeing very little GPU utilization, but 100% CPU usage during 2 stream playback.

* * * * *

My own system is nearly completed with the build. I have Windows 7 installed, SP1, graphics drivers.. starting to bring over some of the content from the old NLE. Later today will install my core apps and see how they run.

Tried to run WinSat (WEI) and it couldn't complete--Google and MS revealed that it is a bug in WEI with processors over 16MB cache ram. I have 40MB cache between my two processors. I thought it might be the large amount of RAM, but apparently there is a hot fix for it.

The new system is a server motherboard, has two Intel E5 Xeon CPUs, supports 1TB of RAM and has a Titan X as the GPU. For storage, I have the new Samsung 2TB SSDs. I have two 10Gb LAN ports on this thing.. wonder what I'm going to do with those. That should handle 4K nicely. Total system cost was well under $30K. And a friend of mine told me that a producer in Hollywood said that to edit 4K takes a six figure investment in hardware. He must be thinking of Black Magic Designs integrated system hardware for DaVinci Resolve.
 
I'm editing 4k easily on a late 2012 iMac with 24 GB RAM anf only 2 Gig's VRAM. My footage is playing from the internal Fusion drive as easy as it is from my RAID over Thunderbolt...
Cost: 2000,- ;)
 
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