SSD writing and reading speed for cache

[matheusrvdc]

I'm currently upgrading my PC, and while I'm aware that moving from 64 to 128GB RAM will improve its AE performance significantly, I'm wondering about SSDs and the overall media cache performance. My question is: how fast does the SSD dedicted to cache need to be?

A gen 4 NVMe with speeds up to 7GB/s will provide me a very noticeable fludiness over a gen 3 NVMe with 3GB/s? Or the writing/reading speed in such cases is not so determinant that even a normal sata with 500MB/s would be enough and not bottleneck the caching/playback?

From what I've been reading here and there, very high speeds would be sort of overkill, as After Effects usually don't need to write/read data in order of GB every second, but I wanted to confirm it to make sure I don't spend money unecessarily on a super fast SSD that wouldn't really provide me any real benefit for daily AE work.

[ShiveringCactus]

Once you start getting into the weeds on performance, I struggle, but often refer to this article on School of Motion:

https://www.schoolofmotion.com/blog/after-effects-computer

They spec out a high-end PC having spoken with Adobe's engineers and if nothing else, it helps confirm what elements can make a performance difference.

[matheusrvdc]

Yeah, it's not so easy to find material covering these aspects, and it's quite confusing to me cause I can't seem to find a consensus.

I had come across that (pretty good) article from School of Motion few days ago, and yeah, in that case they recommend gen 4 SSDs. But at the same time, there's a test ran by Puget Systems in which they stated that there isn't much difference between Sata, NVMe 3.0 and NVMe 4.0 for AE:

https://www.pugetsystems.com/labs/articles/adobe-after-effects-cc-2017-disk-cache-performance-analys...

So, some people say you should get the fastest SSD possible, others say you don't need to overspend in high end SSDs cause it'd be overkill and you can get pretty much the same speed with cheaper hardware. It's not so clear which direction we're supposed to go to improve cache peformance.

[ShiveringCactus]

I'm not convinced an expensive cache drive makes all that much difference, but the more you use it the faster it will wear out.  I learned that after setting up a new PC last year.  For future builds, I'm going to look at ease of swapping SSDs as a feature.

AE for me has always been about RAM, the more I have the better the "performance" - in quotes, because for me it's about how much I can preview and how many layers I can have.

[Roland Kahlenberg]

Frames rendered in RAM gets written to the Cache Folder/Drive when AE needs to push out these rendered frames to make spacec for new data/rendered frames. 

So, the cache drive is used for AE to write rendered frames from RAM.

The cache drive is also used by AE when you initiate a Preview and AE recognizes that the frames it requires for this preview reside in the cache drive. 

So, AE's cache drive is used by AE to read rendered frames. 

And, the frames AE renders are a composite of what's on the timeline. So, there are no layers but just a single layer representating the visual information of the timeline.

A 500MBps SSD is sufficient to initiate a Preview for a HD1080 comp without any lag; meaning AE should be able to playback the Preview immediately or after a few short seconds. 

Rendered frames stored in cache are denoted by a thin Blue Line at the top of the timeline. When you initiate a Preview with frames stored in the cache drive and these frames are invoked, you should see the Blue Line turn to Green as these frames are loaded into RAM for playback by AE. 

With a slow drive, you will notice a lag as AE reads from the slow cache drive and then drops them into RAM for actual playback. If you have a fast drive for cache, AE can read quicker and then write faster, to RAM. 

HTH
 

[UnderTheStairs]

Hi Roland,

So essentially then, if I have adequate rAM installed and I'm working mostly in HD, using an SSD that's able to read/write at anything more than 1000MBps is overkill for a cache drive and a media/project drive with AE?

You're saying a SATA SSD will be fine - no need to install an NVME SSD?

Thanks.

[Warren Heaton]

If you have sufficient RAM and fast storage (fast-ish being read and write speeds above 800Mb/second and fast hopefully 2,500Mb/second or better), then faster processors and more cores is the next upgrade.

[UnderTheStairs]

Thanks Warren - but from what Roland is saying, 2500mb/sec is generally overkill isn't it? I'm assuming that AE will rarely have to write or read that amount of data per second when working at HD? 

I've seen the OWC Envoy external enclosure. It gives max speeds of about 1500mb/sec and it sounds like that will be adequate for a cache connected to an M2 Mac Studio via thunderbolt 4.

[Warren Heaton]

It's not too late to exchange the M2 Mac Studio for something with larger Flash storage by any chance?  Yes, it's pricy, but it's up there in the 5,000 to 6,000 MB per second range.  At those speeds, it's actually the deal of the century.  Apple's internal Flash storage makes for exceptional cache performance in all things Adobe.

Personally, I've always gone with as large of Flash storage as Apple's offering since they switched to Flash storage as standard in the laptops (2013, I think), keeping it to 4TB since they've provided 8TB options.

OWC makes some great storage products.  Rather than the Envoy, I'd go with something that offers better cooling under extended workloads like the ThunderBlade, Express 4M2, Mercury Pro U.2 Dual, or Gemini.

[UnderTheStairs]

Thanks once again Warren - and I hate to labour the point but from what Roland is saying, 2500mb/sec is generally overkill for a cache drive isn't it?  

I concur with the OP, it's SO hard to get a definitive answer on what is a pretty crucial question for AE. 

thanks. 

[UnderTheStairs]

...also, thanks for the suggestions - I looked at the OWC Express 4M2 but it requires 4 striped SSD's to function at full speed and for me in terms of space and cost that's overkill for a dedicated cache drive. Still not clear if it's overkill

for speed. 

[UnderTheStairs]

...and also yes, the internal SSD's in the mac studios are crazy fast but I don't want to put the cache folder on there as I want to leave that purely for OS and apps and avoid heavy write counts/prolong drive life.

[Roland Kahlenberg]

Is your question about getting a drive for AE's Cache or General/Production Storage? 

Somehow, the dialog seems to have changed. And this thread is probably the third time I am replying to on choosing an ideal drive for AE's SSD. The issue isn't that the answers are confusing, from what I see. I suggest you know what it is you want to know and stick to it. Jumping from one topic to another is certainly confusing. 

My last word on this is this - 500MBps is good enough for AE's CACHE, for HD1080 projects. BUTT, if you can afford to go up to 1,500-2000 MBps then do it because this still set you up for 4K too. AND ... when you make a primary purchase, you are doing so for the next 3-5 years and not for use, for today. 

HTH

[UnderTheStairs]

Question is mainly about a cache drive and this is helpful, thanks Roland. 

[Warren Heaton]

MacWorld had an article about there possibly being an issue with the life span of the Flash storage when the M1s were first introduced, but then later updated the article to say that users should expect something like 8 to 10 years.  I use TechTool Pro's TechTool Monitor to keep an eye on storage media health and also Carbon Copy Cloner to make sure all the data is in two locations, but that's not because I'm worried about the internal Flash storage failing early.  It because I know all stroage media will fail eventually. 

As far as bandwidth goes, here's a quick calculation:
I have a Comp open that's 4096 x 2160 at Full Resolution requiring 67.5 MB per frame at 16 bits per channel running at 29.97 frames per second.  68 times 30 is 2,040.  Playing from RAM, 2,040 MB per second should be fine; however, playing from storage media that's slower than that - probably not.  Of course, dropping to Half Resolution brings that down to 17 times 30 or 510 MB per second.

[UnderTheStairs]

Thanks Warren.