Only 16fps playback from 4K Extreme / Resolve / Mac

Hi There

Does anyone know of a bottleneck that would cause 4K Decklink output (either HDSDI or HDMI UHD) to only get to 15/16fps?

Getting realtime in the GUI all the time but as soon as I turn the card on it maxes out at 16fps regardless of slot configuration.

This is playing a 4K DPX (3840 x 2160) sequence - no nodes / grades just straight playing from the RAID.

Configuration:
Mac 8 Core 2.26 w/ 24GB Ramm
10.8.4 / Latest full Resolve 9.1.4 / Latest desktop video 9.7.3
Blustor PCIE Extender with 20TB RAID giving 1.5gbps read/write.


Slot1 - GTX 680 for MAC (GUI only)
Slot 2 - Expander to RAID / Rocket / Nvidia Quadro 4000 (GPU)
Slot 3 - Decklink 4K Extreme
Slot 4 - HDMI breakout plate

I should add that I have tried this in pretty much every configuration (including more GPUs in the extender). Tried single GTX 680 as GUI/GPU and no GPU in extender as well as Quadro 4000 / Quadro 4800 as single GUI/GPU in slot 1 / Also tried 4K extreme in slot 1 for 16x bandwidth. Attempting to put the 4K extreme in an 8x slot in the expander results in kernel panic at boot.

I'm getting realtime 4K DPX playback in Scratch so I know the RAID is up to it. In Resolve it's realitime in the GUI with no decklink but only ever get 16fps when trying to monitor 3840 x 2160p. I also get realtime via the card when monitoring 1080p and then it chokes when going to 2160p.

Looking for a solution so any ideas welcomed!

Thanks

Jeff Brown
http://www.brownianmotion.co.uk

[Dwaine Maggart]

What is the model number of your MacPro?

[Peter Chamberlain]

The q4000 is suitable for GUI, swap that with the gtx680 physically and connect he GUI monitor to the 4000. You should also select the "optimized display mode" on project settings, it in the conform section ... I think.
Peter

Thanks guys. Spec is:


Model Name: Mac Pro
Model Identifier: MacPro4,1
Processor Name: Quad-Core Intel Xeon
Processor Speed: 2.26 GHz
Number of Processors: 2
Total Number of Cores: 8
L2 Cache (per Core): 256 KB
L3 Cache (per Processor): 8 MB
Memory: 24 GB
Processor Interconnect Speed: 5.86 GT/s
Boot ROM Version: MP41.0081.B07
SMC Version (system): 1.39f5
SMC Version (processor tray): 1.39f5
Serial Number (system): CK94305A20H
Serial Number (processor tray): J593600721LUE
Hardware UUID: B0136638-2D6C-5888-A4AE-5F6B9312A7F0

I've now added another expander - one for the RAID and one for the GTX (GPU only) so as not to be hoggin that bandwidth on playback. It's 2 x JMR 8x expanders linked into a single bridge card on slot 2 16X.

I've selected the optimised playback option and now I seem to have realtime on the GPU in the Colour window indicator (that was always at 16fps).

My GUI playback now stutters in what looks like around 15-16fps - so I'm assuming it's assigning resources to the Decklink feed instead?

No 4K monitor in today to test - 80+ inch TV coming in tomorrow to test the UHD over single HDMI input.

If all works out fine I shall report back and let you know.

Thanks.

Hi Jeff,

Fancy meeting you here!

My grading machine has much the same setup – a Quadro K5000 in Slot 1, PCIe expander in Slot 2, HDMI breakout in Slot 3 and Decklink in Slot 4.

My expander has a RAID card and three Quadro 4000s.

I can play back 4k through the Decklink OK, and my Mac Pro is pretty long in the tooth (Early 2008 MacPro3,1).

The only thing is that I use a CUBIX PCIe expander that has a x16 interface – yours is x8 I think – however, I can't for the life of me think why that would make a difference! I didn't quite understand your last post – did using the x16 splitter expander fix the issue?

Would be good to catch up soon, Jeff.

Adam

HI Adam!

Yes I think it's fixed though I suspect it has more to do with the "optimise playback" setting which I missed. The main reason I've gone with two expanders is the power connections on the GTX680 come out the side not the back meaning I can't put the lid back on the rackmount Blustor - had to stick it in a desktop Silverstor instead

I'll know if it's all working tomorrow when I have a 4K monitor to play it on....

I didn't think it was the GPUs as I was getting constant results on the Decklink even with 3 x GPUs in there.

Loving the cutting edge

Hopefully catch up with you sometime soon.

Cheers

Jeff

For anyone that's interested - the above worked fine.

I suspect the "optimise for playback" setting had the most impact.

I effectively got 15-16fps stutter in the GUI and realtime via the decklink.

Thanks for all the input chaps!