View Full Version : I7 CPU using PPro CS4. Why so slow?


Rob Johnson
January 13th, 2010, 02:29 PM
Hi all,

I use PP4 to edit my AVCHD files under Windows 7 (64 bit).

I've been looking for the answer to this since last year and as of yet haven't found an answer.

I'd like the simple answer to this; why does PP4 (or more specifically Adobe Media Encoder) encode video SO slow under the i7?

It consistently uses only 25% of my CPU's processing power. Only 25%! This is on a quad-core i7. Usually only two of the cores are running at around 50%, hence 25% total. That means I'm rendering video at about 1/4th the speed. It could be rendering about 4 times faster if AME utilized all 4 cores better. At least AE gives you the option to utilize all 4 cores in the preferences. This is putting me in slow-ville. I feel like I have a Formula One car being driven by Hervé Villechaize.

So what's the dirt? Why does this happen and is there any way I can remedy this situation? Thank you.

Battle Vaughan
January 13th, 2010, 02:36 PM
I don't know, but have a suspicion the preferences > general >optimize rendering for memory / performance option might be involved. Might be worth a comparison test? / Battle Vaughan

Harm Millaard
January 13th, 2010, 03:43 PM
Most likely the CPU is waiting for other components/processes/services to finish, thus sub-optimal performance. Every brand system is crippled from the start. You have to optimize each system for performance.

Rob Johnson
January 13th, 2010, 05:15 PM
I have PP4 set for optimal performance. It isn't really PP4 where the bottleneck is occurring but rather Adobe Media Encoder.

As far as system processes, I shut everything down except for critical system processes (which usually can't (and shouldn't) be shut down). At the time just before rendering, Sytem Idle is probably the only process using any noteworthy CPU power, and which naturally would end once rendering begins.

Sometimes I run an old version of AVISynth to encode video files to x264. And when I do, all 4 cores are going balls-to-the-wall at 100% and I pump out encodes in record times. The same goes for some other programs. So if this this old, crusty version of AVISynth can make the cores talk to each other properly and fully utilize the CPU, I'd think AME CS4 would be able to do the same.

This is not a hardware problem, it's an Adobe problem. One which they should, IMO, give high priority to correcting. After we've fully and painstakingly optimized our system/software/hardware/plugins for CS4, it's yet another hook to get us to move to CS5.

Harm Millaard
January 14th, 2010, 03:58 AM
It may be an Adobe problem if others can replicate this behavior. I for one can not. I have no trouble getting all cores at 100% during encoding. Therefore my conclusion is it is something in your setup, not an Adobe problem.

Rob Johnson
January 14th, 2010, 04:28 AM
There are complaints of this strewn across the net in various forums. I'd be happy to post the links. Specifically, users with I7 processors trying to use AME CS4. Clearly the problem is far from unique to me and my system alone, and much more universal.

Since Adobe Media Encoder CS4 is working so well on your I7 computer, perhaps you'll be good enough to share with us what your work flow is and specifically how your system is set up.

Harm Millaard
January 14th, 2010, 05:31 AM
This is my setup and my workflow is usually XDCAM/HDV/DV with 5.1 sound exported with AME to H.264-BR/MPEG2-BR/MPEG2-DVD/MPEG2 I-frame 1920x1080 for further encoding with HC.

I suggest you try the PPBM4 home page (http://ppbm4.com) benchmark and mail the results to Bill to see where your system performance is in relation to others. Maybe that will give an inkling of what is going on.

Pete Bauer
January 14th, 2010, 05:43 AM
Thanks for posting your system info, workflow, and Bill's PPBM4 link again for the umpteenth time, Harm. Just speculation on my part, but most people don't have the super-speedy RAID setup that HARM has. I wonder if on some systems the h264 encodes are actually limited by disc write speed rather than processor as one might normally expect?

Rob, you'll help others help you if you give more info about your system including amount of RAM, any overclocking, hard drive set up (inlcuding RAID), scratch disk config. For instance, if you're doing everything on a single 7200rpm HDD, expect poor performance regardless of processor. BTW, your DVinfo user profile says you're using PPro CS2.

Rob Johnson
January 14th, 2010, 07:33 AM
Pete, I'm running Adobe Creative Suite 4 under Windows 7 64 bit, on a quad-core I7 processor, each core clocking at 2.6GHz. I have 12GBs of RAM. There are two 7200RPM HDDs, One for the OS and the other for video files and as a scratch disk.

On Sisoft Sandra 2009, my system components pass benchmarks with flying colors.

I'm not doing uncompressed video. I don't deal with Terabyte sized video files. So how can disk write speed be a factor? If I were trying to write a sustained 100-200MB/sec to the drive I could see the problem, but I'm not writing at nearly a fraction of that speed.

On my last encode, I was encoding an edited AVCHD clip to a Quicktime MPEG4 video file, 1920x1080 at 15Mbit/sec data rate. The final size of the QT MPEG4 file was 900 MBs and took around 40 minutes to render. I get about the same speed as that using my nearly 7 year old Pentium 4. C'mon, doesn't that just wreak of something wrong?

And as I stated above:

"I run an old version of AVISynth to encode video files to x264. And when I do, all 4 cores are going balls-to-the-wall at 100% and I pump out encodes in record times. The same goes for some other programs. So if this this old, crusty version of AVISynth can make the cores talk to each other properly and fully utilize the CPU, I'd think AME CS4 would be able to do the same."

So obviously my system is not inherently "crippled," at least until it comes to AME 4. How is it that AVISynth and other programs can bang the needles on all CPU cores, and yet AME 4 crawls like a snail through a cold, dry garden?

Harm Millaard
January 14th, 2010, 10:30 AM
Unfortunately those flying colors turn to black and white when editing. 2 disks is not enough for comfortable editing as you experience. Your CPU is waiting for the disk to store the temp files, do housekeeping, and a lot of other things and while waiting it has nothing else to do. Hence the 25% figures. The disks seem to be your bottleneck. Running the benchmark I previously pointed you to, may help to identify the bottleneck in your system.

Roger Keay
January 14th, 2010, 11:45 AM
I have experienced encodes with 15% -20% CPU utilization in the past but the issue seems to have been resolved. I use a computer with an i7 920 processor, 6 GB RAM, system C drive and a pair of 500 GB 7,200 rpm drives configured as a RAID using the hardware on the Asus motherboard. The machine runs Vista 64 Home Premium and CS4 4.2.1 with both the OS and application kept current. I do not have anti-virus software installed as the machine is only used for media applications. AME is version 4.2.0.006

At present, I have approximately 80% CPU utilization with AME for H.264 and MPEG2 encodes. The source projects use the HDV preset. The task monitor display shows the 4 physical, 8 virtual hyperthread processors running at close to the 80% mark on average. There doesn't seem to be any problem with disk access which typically runs below 5 MB per second with both the source and destination file on the RAID. This morning I did a test encode. A 112 second HDV project encoded using a standard AME MPEG2 1440 preset and Dolby stereo audio in 94 seconds (84% of program time). The same project output as H.264 took 262 seconds (2.4 times program time). I also tried a Cineform 1440 by 1080i project to Blu-Ray MPEG2 that yielded an encode time of 2:56 from a program length of 3:49 (77% of running time). Cineform decodes take less CPU time than HDV which probably accounts for the 77% of running time versus the 84% with an HDV project.

I have a reasonable knowledge of computers but I am far from being an expert. The computer is not overclocked and I have not done any performance tweaks to increase speed.

Adam Gold
January 14th, 2010, 12:58 PM
Harm, would it be possible for you to post a screengrab of your scratch disk setup page as well? Your system info is really useful and much appreciated.

Steve Nelson
January 14th, 2010, 02:12 PM
Hi Rob,

Ideally you would want at a minimum separate physical disks for source and destination when rendering. A good minimum system has an OS/Apps drive, an audio/video source drive and an a/v destination drive. Of course you can get fancier with RAID etc but at a minimum three drives is a good baseline system.

I'm running a setup similar to this currently although I have external eSATA drives that I can go mobile with as well and bring back to be processed. They're useful for multicam gigs with other operators. I'm also running an i7 920 system with 12Gb RAM, 2 1Tb internal drives and a 1Gb NVidia Quadro FX 3800 video card. I overclock the i7 to about 3.2Ghz and get excellent render times even when using Magic Bullet Looks which is notorious for glacial renderings.

Rob Johnson
January 14th, 2010, 02:23 PM
Roger, I am fully updated and running the same version of PP and AME as you. I was running Vista 64 before I went to Windows 7, and was having this same problem with everything running under Vista 64. So I think the OS can be ruled out. It would be the least probable suspect anyway.

Aside from your RAID configuration it sounds as though our systems are similar. 80% CPU utilization is quite good and, at least in my opinion, would be considered satisfactory compared to my current measly 25%. By chance have you ever worked with or attempted to encode AVCHD files?

Rob Johnson
January 14th, 2010, 02:42 PM
Steve, thanks for your input. I understand what you're saying about drives. Even when I was running 3 drives (OS-Apps/Source/Destination), I was still experience the same problem.

And if you take into account everything I've said in previous posts to this thread, I fully do not believe that the drive situation is the problem. If it was, it would have been flushed out before. When I render, my drives are barely doing anything, as if they're waiting for AME to hurry up.

Also there is the inconvenient fact the AVISynth, and almost every other video app I use, makes full use of the processor. 100% or near 100%. Even the After Effects renderer does much better. That's the elephant in the room that cannot be escaped.

It is this that leads me to believe the it is AME specifically that is not playing well with my I7. However this does not rule out other things, such as the AVCHD codec potentially.

Steve Nelson
January 14th, 2010, 03:49 PM
That could very well be Rob. Do you by chance have something that isn't AVCHD to work with to test that theory? I have an EX-1 so I don't routinely work with that format. By chance do you know how to run Performance Monitor and catch a screen cap of that for us?

Specifically, set up counters to capture % Processor Time, Processor Queue Length, Current Disk Queue Length & % Disk Time(for each physical drive) and Memory Pages/sec.


This will give us any idea on what your system looks like while rendering. Want we want to look for is tasks waiting to be executed or queuing up somewhere. If the disk counters are low then you're theory will be proven correct and it will be a matter of digging into individual processes to see how they're performing. What you want to do is show how hard the hardware is working and if it isn't then you can bet that it's an application problem.

Graham Hickling
January 14th, 2010, 08:09 PM
I have an I7 920 with non-RAID 7200rpm disks. It's about average for an I7-920 on the Premiere Perfomance benchmark scoresheet.

When I encode AVCHD clips to 1080i H264 using CS4 AME I get all cores active with CPU utilization fluctuating between 74 and 81%.

You mentioned your problem is with "edited" AVCHD - do you have color correction or whatever applied? Some filters may not be multicore aware ... might explain why Avisynth works OK and (your) AME doesn't seem to.

Rob Johnson
January 14th, 2010, 08:56 PM
Steve, I'll get on it. Please give me a list of the most relevant counters to set up in PM and I'll grab a screen shot. I'll also try encoding to/from some other formats, perhaps ruling out the AVCHD and/or QT codecs playing badly with AME and I7.

Rob Johnson
January 14th, 2010, 09:09 PM
Graham, hmmm, now that IS interesting. I've encoded AVCHD both straight and using a few simple filters, such as a HSL or levels adjust. Same rendering problem on both accounts.

Only difference I can see is you're encoding to H.264 1080i whereas I'm encoding to MPEG4 (Part 2) 1080p. As I said to Steve above, it will be worth a shot to try encoding to these different formats. Based on what you've just said I'll start with that.

Rob Johnson
January 14th, 2010, 09:45 PM
This is my setup and my workflow is usually XDCAM/HDV/DV with 5.1 sound exported with AME to H.264-BR/MPEG2-BR/MPEG2-DVD/MPEG2 I-frame 1920x1080 for further encoding with HC.

I suggest you try the PPBM4 home page (http://ppbm4.com) benchmark and mail the results to Bill to see where your system performance is in relation to others. Maybe that will give an inkling of what is going on.


Harm, Thank you for sharing your information and posting the link to PPBM4. I just downloaded it and I'm sure it will prove to be helpful.

Rob Johnson
January 16th, 2010, 07:23 AM
I have an I7 920 with non-RAID 7200rpm disks. It's about average for an I7-920 on the Premiere Perfomance benchmark scoresheet.

When I encode AVCHD clips to 1080i H264 using CS4 AME I get all cores active with CPU utilization fluctuating between 74 and 81%.

You mentioned your problem is with "edited" AVCHD - do you have color correction or whatever applied? Some filters may not be multicore aware ... might explain why Avisynth works OK and (your) AME doesn't seem to.

Graham, yesterday I did an encode to H.264 1080i and had a processor utilization of 50-60%. I dropped an AVCHD clip in the timeline, no filters no edits, and did the render.

Regarding the AME video export tab, from top to bottom, would you be so good as tell me exactly what your export setting are? I feel I'm making progress and would like to take this further.

Harm Millaard
January 16th, 2010, 08:46 AM
Although directed at Graham, allow me to give you my results, exporting to H.264-BR VBR-1 pass, target 25 and max 30, 1920 x 1080 25i with AC3 5.1 448 Kb sound, results in these rates:

Graham Hickling
January 16th, 2010, 05:19 PM
Rob - these are the export settings for the encoding I mentioned earlier. The original clip was 1080i AVCHD from a Canon HF10.

Rob Johnson
January 16th, 2010, 06:59 PM
Graham and Harm, thanks much for sharing your settings. Graham, I'll try yours tomorrow (Harm is using XDCAM/HDV/DV) ... see what's what with CPU usage and post the findings. If I get similar utilization as you then at least I know it's the encoding codec and not AME.

By the way, Harm. Here are some of the results of your benchmark on my current configuration. What's the verdict?

77.7, secs Total Benchmark Time
10.6, secs AVI Encoding Time
35.1, secs MPEG Elapsed Time
32, secs Rendering Time

Harm Millaard
January 17th, 2010, 08:20 AM
The 10.6 AVI result is pretty disappointing. Compare it to Jim Simons results, he is in the same league and like his system, that score is in the D1 range, belonging to the lowest 25% of all scores. This means that either your disk setup can be improved or you have too many disk related background processes running, like indexing, compression or disk optimizers.

Your MPEG encoding is quite average for the i7. Nothing wrong with that result. It shows that you have a good CPU and in comparison to others you are in the top 25-50% on this test. However, due to your disk intensive results, your rendering test is only mediocre.

Your system can be optimized to give better results. Bill will include your data shortly and he probably will give you similar feedback. On Total time your results are MED, but in RPI only Q1. What that means can be found in the legends on the results page or in the methodology on the conclusions page.

Lars Siden
January 19th, 2010, 02:32 AM
I rendered alot of material yesterday(SD material, 720x576) - I render from a striped HDD array to a single SDD disk. I have a Quad 9450 @ 3.2ghz with 8gb mem and Win 7 x64.

I noticed that renders where I only had cuts(no color processing or so) - AME used about 25-30% cpu - disk usage was about 200mb/sec(resource monitor). When AME rendered projects where I used blur/color processing/etc the cpu was rock solid at 100% - disk down to about 25mb/sec.

My conclusion:

When "joining" files(ie cuts) - only one thread is running

When processing media, all available cores are used.

For me, the latest version of AME works very well(compared to a year ago)

// Lazze

Rob Johnson
January 19th, 2010, 06:11 AM
Rob - these are the export settings for the encoding I mentioned earlier. The original clip was 1080i AVCHD from a Canon HF10.

Using a single AVCHD file in the timeline (no cuts no filters) and using the same export settings, I had a CPU utilization that fluctuated between 67 and 86%. So an average utilization of about 77%.



The 10.6 AVI result is pretty disappointing. Compare it to Jim Simons results, he is in the same league and like his system, that score is in the D1 range, belonging to the lowest 25% of all scores. This means that either your disk setup can be improved or you have too many disk related background processes running, like indexing, compression or disk optimizers.

Your MPEG encoding is quite average for the i7. Nothing wrong with that result. It shows that you have a good CPU and in comparison to others you are in the top 25-50% on this test. However, due to your disk intensive results, your rendering test is only mediocre.

Your system can be optimized to give better results. Bill will include your data shortly and he probably will give you similar feedback. On Total time your results are MED, but in RPI only Q1. What that means can be found in the legends on the results page or in the methodology on the conclusions page.

I added a 3rd external (source) HDD (USB 2.0). Shut down some more processes and programs that booted on startup. Disabled indexing on all drives. I ran the test again two different times. First from the external drive to the destination drive. And then from the OS drive to the destination drive.

First result set:
435MT, Computer Model
93.1, secs Total Benchmark Time
10, secs AVI Encoding Time
37.1, secs MPEG Elapsed Time
46, secs Rendering Time
Intel, CPU Manufacturer
I7-920, CPU Model
2.66, GHz CPU speed

Total render queue time was 9:02

Second:
435MT, Computer Model
80.5, secs Total Benchmark Time
10.5, secs AVI Encoding Time
37, secs MPEG Elapsed Time
33, secs Rendering Time
INTEL, CPU Manufacturer
I7-920, CPU Model
2.66, GHz CPU speed

Total render queue time was 8:42

With some minor exceptions, it looks like everything is relatively the same.



I rendered alot of material yesterday(SD material, 720x576) - I render from a striped HDD array to a single SDD disk. I have a Quad 9450 @ 3.2ghz with 8gb mem and Win 7 x64.

I noticed that renders where I only had cuts(no color processing or so) - AME used about 25-30% cpu - disk usage was about 200mb/sec(resource monitor). When AME rendered projects where I used blur/color processing/etc the cpu was rock solid at 100% - disk down to about 25mb/sec.

My conclusion:

When "joining" files(ie cuts) - only one thread is running

When processing media, all available cores are used.

For me, the latest version of AME works very well(compared to a year ago)

// Lazze

This seems to be a weird area. Sometimes I get faster render times by having no cuts and using no filters. Other times it's faster by adding filters. It seems to depend on which ones are added.

As far as some 3rd party filters, Magic Bullet Looks, for instance, seems to slow down CPU utilization to about 25% no matter what. I haven't used it in a few months since a few upgrades but assume it might be the same.

These days I edit AVCHD almost exclusively. So far I've found the biggest determiner of CPU utilization and render time to be the codec/format I'm exporting to. For example, exporting to QT MPEG4 gives me only 25%. Yet exporting to QT H.264 gives me 75% (all 1920x1080p). I've tried a number of other export formats per this thread. I've had around 75% with most.

The only time I've seen 100% is during Harm's benchmark test. When rendering out the AVI file, (there are 10 in the test), during about the last 1/5th of the render, all 4 cores will peg to 100%. Looking at the timeline, it is during the multiple color-bar portion of the test.