Advanced Disk Caching advice needed

[Adam5E0F]

Greetings everyone,

After a frustrating conversation with Adobe staff, I am forced to post here because they could not provide me with any answers to my questions about disk caching.

First and foremost, I would like to know what disk speeds are recommended for disk caching?  After doing some light research, I found that when using a drive which is very very slow, like lets say an external USB2.0 drive, then the performance will be LOWER than not even using disk caching whatsoever.  If anyone could confirm this for me, that would be great.  Adobe support staff told me that they have no idea if this is true or not.

The reason I would like to know this information is because I do IT work for a business which has roughly 20 iMac machines, with many users who need After Effects on each machine.  The disk cache usage really piles up since every user profile has their own cache, which is rather redundant to me.  Even more redundant is that, most of the users sign onto all the machines, and thus disk cache is created on every single machine, for every single user.  This is really an excessive amount of space dedicated to disk caching across the entire company.

The plan we have proposed is setting a server on the LAN to be the location of the disk cache.  The network speeds here are a VERY strong 1gb/s, and I need to know whether or not I will actually be harming performance by designating the server drive as the location for cached files.  If there is a benchmark I could run to test this, I would appreciate a brief description of the steps I need to take.  I am an IT guy only, I do not know much about how to use After Effects, so if someone can show me any steps on how to create disk cache files after I designate a new directory, and how to test the speed of the rendering(?) while using that cache, I would be able to do some tests myself to discover if the benefit is appreciable vs using no cache at all.

Please let me know if I can offer any more information about the goals of my organization.  I truly appreciate any help offered by the community here.  Instead of answering my questions, Adobe staff refused to give my any advice, and said this forum was my only choice to finding the answers I am looking for.

[Mylenium]

The cache per se has nothing to do with work speed or for that matter rendering except for the most basic use cases where stuff can be played directly from disk without generating a RAM preview. The cache is really just a sham pretending AE would be something it is not when the underlying architecture is simply outdated. Which actually is the point: Over-optimizing the cache does nothing to advance overall performance. It's simply not how AE works and chances are that a contemporary average local SSD provides enough performance even for 4k work, at least for the flattened cache files. The source file I/O is of course its own story. For everything else you might want to start by reading the online help on basic rendering and previewing and ask an artist to provide you with a reasonably heavy project for testing, then simply run previews and renders ad nauseum under different conditions. Again, it's pretty likely you won't see much of a difference anywhere.

Mylenium

[Martin_Ritter]

Caches files are by default only used while working on the project, not for the final rendering.

Since AE tend to re-render the preview even on the most light changes (removing a marker, for instance), the cache is rewritten all the time. It really just speed up preview rendering if you are working on the same scene for hours.

As Mylenium said, it's not that important at all.

My AE cache is on a NVMe disk, which can tansfer data with about 1GB/s. Most of the time, I see transfer speeds of 60MB/s, but occasionally the speed is up to several hundreds of megabytes per second.

The transfer speed of your network will be fair enough, but if the fileserver cannot handle multiply access of very small data in large amounts, you might end up with a bottleneck.

My advice for you is to monitor the cache drive on all computers for a while (i/o speeds, access times, ... ) to get an idea what is going on there.

Then you can test the server stats against those values and eloborate if it is worth trying.

Or you just remap the cache and if no one complains, everything is good. 😉

*Martin