-
Decklink HD card causes disc activity interference – anyone else have this?
I have had this issue since we first bought our G5 (dual 2.75/4Gig RAM/NVidia Ultra 6800)) and the Decklink HD card, but only now have I managed to isolate the issue to the video card. Basically, the problem I encountered was that every time there was any interaction with the computer – eg moving the mouse along the dock or just scrolling down a scroll bar – I could hear a faint tick-tick-ticking of the Mac’s internal machinations (for want of a better description) or disc activity.
It was perhaps more of an annoyance than a show-stoppper but the disc activity was amplified when the line-out speakers were turned up in volume. I was on the verge of re-formatting the machine with a view of sending it back for repair given that it is still under warranty, but I just thought I’d take the card out first – and hey presto the annoying ticking sound ceased. (When we purchased the Mac we immediately purt the card in – so we never experienced the G5 without the card.) Also this noise is coming from the Mac itslef and not the external firewire drives.
Recently we have had some trouble in capturing footage using this card but I couldn’t say for certain whether this is connected with the above issue.
It is also worth mentioning that we have 2 other Blackmagic cards – but they are of the Extreme variety – and they do not cause such interference.
So perhaps anyone could tell me whether you have ever encountered this before or whether our card may be faulty? Or perhaps there is a workaround? It seems to me thhe card’s audio Blackmagic output is the culprit causing the interference somehow.
Many Thanks,
Dan Brazil
-
4 Replies
-
I guess I had the same issue here with a Decklink HD. I don’t remember exactly what I did, but I gess I just disabled de Video Desktop (the monitoring of the computer desktop by the Decklink) and the noise stopped. Hope it helps.
[ ]s -
Thanks fo that. I have done that and yes it dramatically reduces the interference – I no longer hear anything when I scroll along the dock, however, I do still hear a faint noise when I resize windows. Infact it is very minimal but if you crank up the volume of the line out you can hear it.
I spoke with the supplier of the card and he recommended that the card be placed in the very top PCI slot – the one that’s numbered #4. Quite a battle to get it in given that it is partially obstructed by the internal SATA connection (poor design here Apple). However, this didn’t affect the noise I was hearing.
I am awaiting a resoinse from Blackmagic tech supprt on this so will let you know what I find out.
-
From Blackmagic tech support:
“I have found that the clicking noise (that we have observed) is due to a fan inside the G5. When working in HD, data writes can be very long compared with SD. Other processes may be trying to occur at the same time and so the fan starts to spin up.
Just as that happens, the data write from DeckLink will finish and so the fans spin down again. The result is a strange clicking or electronic noise emanating from the front grill of the G5. Does that sound like your problem? If so, that’s just the way the cooling mechanism works in the G5 and there’s no way around that other than to have the G5 further away from your ears, eg under a desk. This might or might not explain your problem so please let me know what you think.” -
It didn’t convince me. I don’t have the noise anymore.
My setup:
G5 dual 2GHz
Decklink HD
Multibridge
Sonnet SATA Tempo-X
External Array with 4 drives SATA[ ]s
Reply to this Discussion! Login or Sign Up