GA-P67A-UD7-B3, tricky question. SW video mixer problems with BM cards.

[wolley]

Hi,

My first post here. I hope someone can help me out here with a tricky question. Long story short:
I want use my system, (speced below), as a software video mixer/streaming encoder with primarily Vidblaster and perhaps Wirecast. There is definitely a problem with my and similar hardware setups that produces video stuttering from time to time. The video starts out as 25 fps but suddenly goes down to perhaps 10 fps and after a while syncs up again to 25 fps.
This problem seems to be related to a combination of the following components, (but I haven't yet found a definite asnwer to what is causing this):
- Sandy bridge chipset
- 2600K processor
- Blackmagic video cards

Using the Blackmagic cards in this system without the SW video mixer in the chain works perfecltly, like with for example Flash Media Live Encoder.
What is causing this stuttering problem? Seems lie a delay or sync problem on the buses or something. Any clues here? Any tips appreciated, I can't use this system now as a video mixer...

Thread where this is discussed:
http://forum.vidblaster.com/showthread.php?t=2882

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Win 7, 64 bit Ultimate
Vidblaster Pro 2.12
Gigabyte GA-P67A-UD7-B3 (rev. 1.0)
i7 2600k/16GB(1866MHz)/SSD(120GB)+HDD(2TB)
ASUS GeForce GT430 1GB Silent
BM Decklink Duo
BM Decklink Studio
Datapath VisionRGB-E1S

[Lsdmeasap]

Are you using the latest BIOS for the board, and did you flash the backup BIOS to match?  If not please update the BIOS using Qflash or DOS, then enter the BIOS and load optimized defaults, then save/apply/reboot BACK TO BIOS.   Once in the BIOS again set your SATA settings to what you need, then any other changes you need and then save/apply/reboot again.

Then update the backup BIOS to match the main BIOS, here's how (you may need to use PS/2 keyboard or USB to PS/2 adapter for the KB)
http://gigabytedaily.blogspot.com/2011/02/video-guide-how-to-update-your-backup.html

The issue is likely DPC latency, I know this affects audio, but not certain if it also affects video or not?  Ask your buddies on that forum about that, and then test with this
http://www.thesycon.de/deu/latency_check.shtml

[Dark Mantis]

Hi and welcome.

It sounds like it could be a latency problem. Download and run dpclatency checker from http://www.thesycon.de/deu/latency_check.shtml . Whilst it is running try usinmg the normal programs that have issues and then after a while see how the graph is going. If there are any red bars at all then you have a problem with latency.

He he. Teach me to read the previous post. Seems like Lsdmeasap and I came to the same conclusion.

[wolley]

Hi,

Thanks for helping out. I have already run the DPC Latency checker. From what I remember all is green but sometimes almost at yellow. When the video cards are idle the staples are at the highest values and when inserting an SDI video signal for exmample in one of the inputs the latencty becomes much lower. But never at red.

The latest stable BIOS release is installed. I will have a go with the backup BIOS that I haven't touched yet, and then load the optimized defaults. Perhaps I'll even try the latest beta BIOS file?

[Lsdmeasap]

Latest beta would be fine to use, that's ALL I ever use personally!