A

Anonymous

Intermittent “Unable to allocate memory” error in After Effects, but succeeds on retry

Forum|Forum|4 months ago
January 9, 2026
3 replies
165 views

We are encountering an intermittent After Effects render error:

“After Effects warning: logged one error – After Effects: Unable to allocate 37,641 MB of memory. Either decrease the memory requirements for the rendering of this frame, or install more RAM. (12803 / Unidentified caller).”

What is confusing is that the same composition renders successfully when retried, without any changes to the project, settings, or assets. This suggests that the composition itself should be within memory limits, yet the failure occurs sporadically.

From Adobe documentation, it appears that After Effects may require a large contiguous block of memory when rendering certain frames, and that memory fragmentation or internal memory state could cause allocation failures even when sufficient total RAM is available.

The renders are running on a machine with the following characteristics:

Instance type: c5.4xlarge (32 GB RAM)
No other applications running besides After Effects

My questions are:

Is there any way to determine actual memory usage per frame or per render attempt within After Effects?
Are there known scenarios where After Effects fails due to memory fragmentation or internal memory state, resulting in intermittent allocation errors?
Can retrying a render reset After Effects’ internal memory state in a way that allows the allocation to succeed?
Are there any recommended settings, diagnostics, or best practices to help prevent or debug this type of intermittent memory error?

Additional details:

After Effects version: 24.x (After Effects 2024)

Any guidance or insights would be appreciated.

A

Anonymous

@nishu_kush @OliviaHazel , could you please help with this? I’d appreciate it

A

Anonymous

Hi Team,

Thank you for your previous response regarding our intermittent memory allocation issue. We wanted to follow up with additional findings based on your suggestions and further investigation on our side.

Correction to Previous Message

We need to correct a typo from our earlier message. The error reports “37,641 MB”, but this is actually 37.641 MB (approximately 37.6 MB), not 37 GB. We apologize for the confusion this may have caused.

The Problem

We are intermittently encountering the following error:

“After Effects: Unable to allocate 37.641 MB of memory. Either decrease the memory requirements for the rendering of this frame, or install more RAM. (12803 / Unidentified caller.)”

The same composition renders successfully on retry without any changes. This strongly suggests a transient memory state issue rather than insufficient hardware. The failure to allocate only ~37.6 MB on a 32 GB RAM machine is particularly puzzling and points toward memory fragmentation or an internal allocation issue.

Our Setup

Infrastructure

• AWS Auto Scaling Groups (ASG) scaling EC2 instances based on queue depth

• Graphics queued via SQS (Simple Queue Service)

• One graphic processed at a time per instance (no parallel rendering)

• Instance type: c5.4xlarge (32 GB RAM)

• After Effects version: 24.1

• Multi-Frame Rendering disabled (per earlier recommendation)

Workflow

1 A graphic job arrives in the SQS queue

2 ASG launches an EC2 instance if required

3 The instance renders one graphic

4 After completion, the instance either processes the next job or scales down

What We Found (Memory Terms Explained)

Based on your suggestions, we ran aerender with detailed logging to better understand memory behavior.

Memory terms (brief definitions):

• Physical RAM: Actual RAM currently in use

• Virtual Memory: Reserved/committed memory (including paged or compressed memory)

• Free Memory: Available physical RAM not currently in use

Core Issue: Physical RAM Exhaustion

During rendering, free physical RAM drops to critically low levels.

Evidence from Logs

• 10:00:06 – Free: 0.18 GB | Physical Used: 27.98 GB | Virtual: 28.99 GB

• 10:00:27 – Free: 0.11 GB | Physical Used: 24.0 GB | Virtual: 35.7 GB

• 10:00:31 – Free: 0.10 GB | Physical Used: 23.13 GB | Virtual: 36.9 GB

At these moments, After Effects attempts to allocate ~37.6 MB but fails due to insufficient contiguous free physical RAM, even though virtual memory appears available.

Additional Observations

Memory Fragmentation

• We observe repeated allocate/release cycles

• Memory usage increases by 2–4 GB, then drops by 1–3 GB repeatedly

• This behavior appears to fragment memory, making contiguous allocations difficult

Virtual Memory Exceeding Physical RAM

• Virtual memory reaches ~39.65 GB

• Physical RAM peaks around ~27–28 GB

• Excess memory appears paged, compressed, or reserved, and is not usable for new allocations

Memory Held Until End of Render

• Memory is not released incrementally as frames complete

• Instead, it accumulates throughout rendering and is released only at the end

• We often see a single drop of 15–18 GB once rendering finishes

Our Questions

1. Graphic Size and Instance Sizing

• Does graphic size or complexity directly impact memory requirements?

• How can we estimate memory needs based on: 

◦ Resolution

◦ Effects

◦ Number of layers

•

• Do you recommend instance sizing tiers for different complexity levels?

• Are there After Effects settings that meaningfully reduce memory usage?

2. Memory Fragmentation

• Is this allocate/release fragmentation behavior expected in After Effects 24.1?

• Are there settings to reduce fragmentation?

• We see this even with Multi-Frame Rendering disabled — are there other workflow adjustments we should consider?

3. Memory Release Timing

• Is it expected that memory is held until the entire render completes?

• Is there any way to encourage incremental memory release to reduce peak usage?

4. Cache Management

You previously mentioned purging “All Memory & Disk Cache” before rendering.

• Can this be automated via aerender or scripting?

• What is the recommended cache-management approach for fully automated, headless rendering workflows?

5. ProRes Graphics Support

We plan to add support for ProRes output.

• How do ProRes memory requirements compare to other codecs?

• Should we expect meaningfully higher memory usage?

• If so, how much additional RAM should we plan for?

What We’re Looking For Guidance On

• Determining appropriate instance sizes based on composition properties

• Recommended After Effects memory settings for automated rendering

• Best-practice workflow patterns to avoid memory exhaustion

• Whether this fragmentation behavior is a known issue in After Effects 24.1

• Expected memory requirements when rendering ProRes graphics

Attachments

We are attaching aerender logs that show:

• Memory allocation patterns during rendering

• Evidence of physical RAM exhaustion at failure points

• Repeated memory fragmentation cycles

Bottom Line

We understand that increasing instance size may help temporarily, but we’re looking for a sustainable solution that scales with graphic complexity. We’re seeking guidance on optimal configuration and workflow patterns—not just larger hardware.

Thank you for your help.

Note: We process one graphic at a time per instance, so this is not a case of multiple concurrent renders competing for memory.

Drive link to logs

O

OliviaHazel

Participating Frequently

Per-frame memory stats?
Nope. AE doesn’t show memory usage per frame. Best you can do is watch AfterFX.exe in Task Manager (RAM + GPU memory).
Can AE fail due to fragmentation / internal state?
Yes. This is a known issue. AE sometimes needs a huge contiguous block of RAM, and fragmentation can cause random failures even when total RAM looks fine.
Does retrying help?
Yep. Retrying can partially reset AE’s internal memory/caches, which is why the same render often works on the second try.
How to reduce this?
- Turn Multi-Frame Rendering OFF (big one)
- Purge All Memory & Disk Cache before rendering
- Pre-render heavy precomps
- Don’t give AE all the RAM (leave some for “other apps”)
- Use aerender instead of the UI if possible

Also worth noting: AE trying to allocate ~37GB on a 32GB machine means you’re right on the edge. Intermittent success is exactly what you’d expect in that case.

nishu_kush

Legend

As suggested by OliviaHazel, clearing media cache (Edit > Purge > All Memory & Disk Cache) should help in such cases.

Let us know how it goes.

Thanks,
Nishu

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