# Poor AC3 Transcoding Performace With FreeNAS
**URL:** https://forums.plex.tv/t/poor-ac3-transcoding-performace-with-freenas/187940
**Category:** General Discussions
**Created:** [April 9, 2017, 4:13pm UTC](https://forums.plex.tv/t/poor-ac3-transcoding-performace-with-freenas/187940 "2017-04-09T16:13:16Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Jack-Sparrow](https://forums.plex.tv/u/Jack-Sparrow)
#### Post date: [April 9, 2017, 4:13pm UTC](https://forums.plex.tv/t/poor-ac3-transcoding-performace-with-freenas/187940/1 "2017-04-09T16:13:16Z")
After moving to FreeNAS Corral, I can no longer transcode AC3 audio streams; CPU usage spikes to 100% and the PC grinds to a halt before the video starts playing.
At the moment I’m using the plex-pass docker image, running under a boot2docker virtual machine.
I was wondering if anyone has faced similar issues, or can guide further diagnostics. The server was capable of transcoding AC3 streams before, but 1, 2, and 6 stream AC3 is now unplayable. My next idea is to re-encode audio for the AC3 portion of the library to AAC.
---
### Author:  [@Peter\_W](https://forums.plex.tv/u/Peter_W)
#### Post date: [April 9, 2017, 4:40pm UTC](https://forums.plex.tv/t/poor-ac3-transcoding-performace-with-freenas/187940/2 "2017-04-09T16:40:55Z")
> **[1.5.x - AC3 will not transcode in FreeNAS Corral docker container.](http://forums.plex.tv/discussion/265067/1-5-x-ac3-will-not-transcode-in-freenas-corral-docker-container#latest)**
>
> Heya. Since the encoder changes in 1.5.x, I’ve had failures when Plex tries to transcode AC3 audio (I think this is the thing in common, many files will play fine) for play on Chromecast/Web. Streams will open but be stuck on a spinning circle and...
Perhaps that helps.
---
### Author:  [@Jack-Sparrow](https://forums.plex.tv/u/Jack-Sparrow)
#### Post date: [April 10, 2017, 1:24pm UTC](https://forums.plex.tv/t/poor-ac3-transcoding-performace-with-freenas/187940/3 "2017-04-10T13:24:19Z")
That’s great @Peter_W, thank you very much.
---
### Author:  [@system](https://forums.plex.tv/u/system)
#### Post date: [January 7, 2020, 11:05pm UTC](https://forums.plex.tv/t/poor-ac3-transcoding-performace-with-freenas/187940/4 "2020-01-07T23:05:38Z")