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Speeding up Premiere: when the bottleneck is disk I/O
Hi all:
Recently, while working on a project, I found that timeline playback was often jerky, so I set out to find the bottleneck in my system. First of all, here are my specs:
-Windows 7 and Premire Pro CS6.
-Intel i7 870 2.93 Ghz.
-8 Gb. RAM.
-Quadro FX3800 graphics card.
-A C:\ system drive, a RAID 0 array (using the motherboard’s Intel controller) with 2 7200 RPM disks as media drive, and a SSD for media cache files.(Yes, I know that my system is a bit old, but bear with me).
The projects I edit are mostly DSLR and GoPro footage, and I edit the H264 files directly, without transcoding. I also use Magic Bullet Colorista II (which is GPU-accelerated) for grading.
I opened Premiere along with Argus Monitor, in order to monitor CPU and GPU load during playback. What I noticed was:
-While playing a “normal” timeline (with Gopro and DSLR footage) with Colorista applied, GPU load never goes beyond 25%, and CPU load barely hits 60% at the most. So, despite the fact that both are a bit old, the bottleneck isn’t there. Memory usage doesn’t go beyond 5-6 Gb. either.
-Playback only becomes jerky when the editing is really fast, i.e., when there are a lot of clips that are 1 sec. long or less. But even then, CPU and GPU load never go beyond 25% and 50-60%.
So I thought that the bottleneck was in the disk I/O. I then copied a few clips to my SSD, loaded and edited them in Premiere and did the test again… and the result was the same. When the edit becomes really fast-paced, the system can’t keep up (but, I repeat, CPU and GPU never get overloaded).
Given this, what else can I do to speed up my system? If even having the media files in the SSD isn’t enough… what else can be done?
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5 Replies
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Worth a shot but make sure you don’t have your scopes open. Horrible playback in CS6 with them open.
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Well unfortunately the load on the GPU doesn’t always mean the bottleneck doesn’t have to do with it. The CPU decides how much load is put on the GPU at any one time because the decoding starts there. What is sounds like is the memory management becomes a issue since this happens when using allot of clips. you really should have 16GB of ram with Adobe, HD, and GPU acceleration anyway. GPU acceleration is a ram hog because of how it works. That is where I would start. Beyond that the CPU you have is going to limit the performance next. it’s not just the load on the CPU. It’s how fast the CPU gets the ram buffers created and the frame data decoded every second to move the data down. There may be only 60% load on it but it still will likely have issues getting all of those buffers created in that time frame. It’s time to start looking at upgrading the core system if this work is common.
Eric-ADK
Tech Manager
support@adkvideoediting.com -
Hi Paulo,
A RAM upgrade to 16GB would be a good start for overall system performance.
I’ve never used the onboard RAID controller for RAID 0, always just did a stripe set in Disk Management. Not sure what effect that may have on performance. Turn off “Indexing” for the video drives by right-clicking the drive in Explorer and looking under “Properties > General”, just uncheck that box. Have you ran a Disk Speed Check? A 2-drive RAID 0 ought to provide about 200MB/s. Of course, keep video drives less than 80% full and defragmented as well.
Since the Mercury GPU Acceleration is supposed to play a big part in playback performance, a graphics card update would likely make a big difference due to having LOTS more CUDA cores. On a budget, something like a GTX 660 should really help.
GoPro footage is notoriously difficult to play back even on a fast system, best to use the GoPro Studio software and convert footage to .avi before editing.
Thanks
Jeff Pulera
Safe Harbor Computers -
Thanks for your answers. I’m definitely planning to upgrade to 16Gb., since I need it anyway for After Effects work.
Anyway, I just did a quick test by taking some DSLR and Gopro footage and transcoding it to ProRes LT. Then I created a fast-paced sequence using that footage, added Colorista to all the clips, and…
-No skipping whatsoever. Smooooooth playback.
-CPU usage much lower, as expected (around 20%).
-Memory usage also lower.So I hope that the last point is the key one and the bottleneck is in the memory, instead of the CPU (since the latter would involve upgrading the entire system). I’ll perform more tests after I’ve added the 16 GB. of RAM.
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That unfortunately points to the CPU even more. Pro Res has a far lower compression ratio besides higher efficiency which means far less time processing. Converting the Go Pro to Cineform would likely help this considerably. Although you are running close to the edge of what that CPU can do in a time frame required for smooth playback. A new GPU such as a 660Ti may help considerably just getting the latency down which is what you are running into.
Eric-ADK
Tech Manager
support@adkvideoediting.com
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