AE preferences for 12-core

[Rusty Shackleford]

What’s a good amount of RAM to get? For 12-cores I need 24GB of RAM for MP? What benefits would there be to have more? How does final cut studio use RAM, maxed at 3?

Brandon Morris
http://www.brandonmorris.com

Canon T2i
13″ Macbook Pro (Mid 09) 8GB RAM 10.6

[Todd Kopriva]

See this page and the resources that it points to for information about memory, multiprocessing, and performance:
https://forums.adobe.com/thread/543440

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Todd Kopriva, Adobe Systems Incorporated
Technical Support for professional video software
After Effects Help & Support
Premiere Pro Help & Support
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[Kevin Camp]

also, your 12 physical cores is actually 24 logical cores with hyper threading on, so ae will see (and use) 24 cores and it will need ram for each.

i get by with 16gb of ram on a 8-core (16 with hyper threading). however, i still mostly work cs4 (to maintain compatibility with other work stations) and cs4 would top out at around 3gb per core, so i’m at around one 3rd of the max…

i also monitor cpu activity, ram usage and disk activity and often make settings adjustments for certain comps to get better performance when needed… having more ram means you won’t need to make many adjustments very often, ae will run more smoothly and efficiently in more situations and that can make your life easier.

i’ll also add that many effects and processes in ae are multithreaded, so those processes will use multiple cores regardless of the ‘render multiple frames simultaneously’ setting… so you’re not completely losing those extra cores without it, but more ram will allow you to use that feature and it will speed up many renders… though maybe not 24x faster.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Todd Kopriva]

Regarding the high end…

In our testing, we see a performance plateau around 8-10 rendering processes. (Things like I/O and RAM bus speed start to emerge as the bottlenecks.) So, if you have a machine with 24 logical cores, you’ll get maximum performance only using half or fewer of them for background rendering processes. If you put 48GB of RAM in such a machine and left a third of it for other applications, After Effects would have all that it needs.

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Todd Kopriva, Adobe Systems Incorporated
Technical Support for professional video software
After Effects Help & Support
Premiere Pro Help & Support
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[Todd Kopriva]

> even with half the cores for other apps i generally see high cpu levels across all cpus.

Yep. That’s what happens with a multi-threaded application. The preference for reserving CPUs for other applications only keeps After Effects from starting up separate background rendering processes on those CPUs; it has nothing to do with multi-threading.

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Todd Kopriva, Adobe Systems Incorporated
Technical Support for professional video software
After Effects Help & Support
Premiere Pro Help & Support
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[Kevin Camp]

[Todd Kopriva] “we see a performance plateau around 8-10 rendering processes”

interesting… i had noticed that 8 cores for ae and 8 for other apps seemed to give me the best performance, though i thought it was due to somewhat limited ram…

even with half the cores for other apps i generally see high cpu levels across all cpus.

the only settings i adjust are ram for other apps and min ram per cpu… some comps like having more ram per cpu, some like more cpus, and a few seem to like the os to have more ram, which seems to be to reduce the os’s use of disk caching.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Touko Maksimainen]

Todd, what are your thoughts on just turning Hyperthreading off? It seems a bit questionable to reserve 3 gigs of RAM for virtual processors? (ie. allocating actual resource to imaginary instance). I read it somewhere that 20% is the maximum performance gain from using Hyperthreading in the first place, it doesn’t seem reasonable to buy twice as much RAM just for that?

Thanks to Hyperthreading, the number of cores After Effect sees can be so high that if you want to make sure all processes get the recommended 3gb you’ll have to spend an insane amount of money for RAM. Some of the latest hardware can field up to 32 logical cores so you’d have to get 96gb of RAM for that. (Instead of 48 with HT off)

For many of us that is not affordable, so wouldn’t it make sense to switch off Hyperthreading completely so that you are able to allocate your limited RAM to where it matters (the physical cores.)?