I increased CPU utilization from 45-55% to 70-80% during renders

[Michael Buie]

I have found a lot of great advice here on these forums, so I thought I’d share my experience with you guys since I’ve seen similar questions pop up here. 🙂

[Gary Huff]

What have you described in no way accounts for CPU utilization by Premiere. Altering Page File sizes like you have can also make Windows unstable.

[Michael Buie]

So, are you saying your CPU utilization does not go up when you render?

[Gary Huff]

No, what I’m saying is that what you did with the hard drives shouldn’t have impact how much CPU was being utilized.

[Michael Buie]

I posted my experience thinking someone here might want to see it since I saw some folk complain about why their CPU utilization is low on high-end machines.

I felt since my old Q6600 2.4 GHz PC rendered at nearly 100% CPU utilization and my I7 950 PC was only rendering about 50% CPU utilization, my drives were the next suspect for being a bottleneck to overall performance.

My actions of optimizing caching and rendering files to my fastest drives resulted in my PC rendering approx 35% faster! Higher CPU utilization resulted, more frames render per minute, files complete exporting quicker and sequence renders complete faster.

I made no other changes. What would you attribute that to? Are you going to totally disregard the results of the change?

[Michael Buie]

Check out this post by a guy discussing Pipelines and Performance:

https://www.virtualdub.org/blog/pivot/entry.php?id=31

Pipelines and performance

First, a classic laundry analogy: think of pipeline stages in terms of your washer and dryer. The fact that your washer and dryer are separate instead of being one washer-dryer amalgam is that you can get more done by keeping both busy: while one load is drying, you can start the next one in the washer. However, there are some gotchas to this:

The washer and dryer probably don’t run at the same speed, so one of them will always be the bottleneck. If your washer takes longer than the dryer, the dryer will be idle some of the time (pipeline stall). If your dryer takes longer, you’ll sometimes have clothes sitting in the washer (underutilization).

The pipeline only runs as fast as its slowest stage. If your washer takes 30 minutes and your dryer takes an hour, getting a faster washer isn’t going to speed up four loads of laundry as much as a faster dryer.

You can keep the washer and dryer running more often if you have an extra basket lying around. That way, you can empty the washer and fill the dryer as soon as they’re ready, and you can merge or split loads as necessary. (When I was a college student, I quickly learned that a full washing machine will work about as well as a half-empty one, but a full dryer takes forever compared to a half-empty dryer, so sometimes it pays to dry smaller loads. Part of the reason is that you can empty the lint trap more often.) However, having ten baskets instead of one or two doesn’t help and is just a waste of space.

There is some overhead to shuffling clothes into the washer, from the washer to the dryer, and out of the dryer; the longer you take, the longer the units sit idle and the lower the overall throughput. This means that putting one load through actually takes slightly longer than if you had both in one unit. The longer the washer and dryer take, though, the less your movement delay matters. One way to do this is to do bigger loads.

It’s embarrassing to store up dirty clothes for three weeks and then have to tell people you can’t do something because you have to spend the next three hours doing laundry.

[Walter Soyka]

[Gary Huff] “No, what I’m saying is that what you did with the hard drives shouldn’t have impact how much CPU was being utilized.”

If hard drive access was a bottleneck, the CPUs wouldn’t be fully utilized because they couldn’t be fed data to crunch from disk fast enough. By improving disk throughput (in this case, by distributing the system, media, and caches across separate spindles), Michael has reduced or eliminated that bottleneck, allowing the CPUs to work closer to their capacity.

Rendering requires multiple subsystems (CPU, RAM, and disks) to work together. Any one of these subsystems can be a performance bottleneck which slows the others down.

Michael, I’d suggest you consider getting a high performance RAID system rather than faster individual disks. You can get very fast read and write speeds and a larger volume size. RAID is not backup, but you’d also get some redundancy protecting you against the failure of a single drive.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog – What I’m thinking when my workstation’s thinking
Creative Cow Forum Host: Live & Stage Events

[Michael Buie]

Walter! Finally! A great reply!

Your response backs up similar advice from a Adobe Forum member who helped write PPBenchmark. HE also agreed I had taken some steps in relieving a bottleneck and his number one advice to increase my performance further was to RAID, as well. 🙂

I WAS going to get a 15K RPM SAS drive and controller (I already have the controller, Dell XT257 Perc5/i PCI-e SAS RAID 256Mb Controller, as a matter of fact). But, the RAID solution seems more cost effective, based on what you guys are telling me.

Thank you so much for the verification and the advice!

[Gary Huff]

Adding a RAID is great advice. Defragging won’t show any difference and changing the page file can make your system unstable.

[Michael Buie]

I can’t evin BEGIN to explain how wrong you are about defragging on so many levels. You revealed a lot about your lack of knowledge of hard drive performance with that one statement right there. Sorry to be blunt … but, that is just being real.

Changing the pagefile CAN make your system unstable if you don’t do it right. But, that is such a broad, misleading statement.

Editing your Registry can also destabilize your system if you don’t do it right.

Deleting files from your hard drive can make your system unstable if you don’t do it right.

That doesn’t mean you never do it.