Transcoding Problems with new Hardware

Hi,

at first my Setup:

- Supermicro A1SAi-2750F Mainboard (Intel Atom C2750 with 8 Cores)
- 32 GB Ram
- Digital Devices Max S8 DVB-S Card

- Ubuntu 14.04.3 LTS

I tested with 4.0.5 (stable) and with latest nightly (4.1-639~gd7456e7) with same result.

My House Clients are Rpi2 with OpenElec, all is running fine.

Now i try to do transcoding, but if i start, Sound and Picture stuttering and the Web Interface reacts really slow ...

CPU runs on half Power (round about 400%).

Can't find reason why Transcoding isn't working ...normally this HW can transcode 2-3 1080p Streams without problems...

I tried different Profiles (defaults and own )

Any Ideas?!

Thanks a lot
Cheers

update: SD Channels work without Problems ... HD Channels not ...

I test with exact the same ffmpeg line from my OSX Machine ("only" quad core) the HD transcoding ...

I think its something with libx264 codec ... OSX transcoding working fine ... on the machine not ...strange

Is THV using VLC for transcoding?