1 Topic by undertone (edited by undertone 2009-11-19 19:00:43)

  • Registered: 2007-05-02
  • Posts: 316

Topic: MF/PCI as system audio in W7 64-bit = High latency ASIO

In 32-bit XP and Vista, I used to assign the system audio to my MF/PCI (analog 1+2) and I had no latency issues with ASIO softsynths when running them through alternate channels (analog 7+8). I ran at 256(6 ms).

Now that I'm in Windows 7 64-bit and assigning the same channels to system and ASIO (using the latest 3.082 drivers), I was surprised that when using the same 6 ms setting Kontakt 4 had very noticeable latency (maybe 60-80 ms), while in Kontakt 3.5 it's now unbearable, seemingly close to half a second. If I assign the system to on-board audio, all is well and normal again with ASIO.

I'll have to route the motherboard audio to 2 analog ins of my MF and change the system audio when I want to listen or watch multichannel material. No big deal, but I though you should know of this change. I'm also curious to know if others have experienced this as well.

PC1 = HDSPe PCIe: DF-ADI-8 DS / HDSPe PCIe: MF2
MBP = HDSPe Expresscard: MF1

2 Reply by undertone (edited by undertone 2010-01-08 08:32:54)

  • Registered: 2007-05-02
  • Posts: 316

Re: MF/PCI as system audio in W7 64-bit = High latency ASIO

I'm updating this thread because since I posted the above, I keep experiencing the same thing: sometimes the buffer size increases for no apparent reason. It's happened to me in more than one host and even with standalone VSTi's, and in most cases going to the HDSP settings and toggling the buffer size solves the problem.

So it's not mission critical but I can't figure out what causes the buffer size to suddenly increase like that. Maybe it's because I'm running two PCI cards? I'm using a MF1 and an HDSP9652 in the same machine, both synced to wordclock from an ADI-8. Very strange.

PC1 = HDSPe PCIe: DF-ADI-8 DS / HDSPe PCIe: MF2
MBP = HDSPe Expresscard: MF1

3 Reply by MC

  • MC
  • MC
  • Administrator
  • Offline
  • From: Germany/Thailand
  • Registered: 2007-04-06
  • Posts: 25,537

Re: MF/PCI as system audio in W7 64-bit = High latency ASIO

I think you use the same channels for WDM and ASIO, maybe without noticing. The buffer size did not change at all. What you experience is a complete buffer wrap-around, which then causes such a big delay. And this one can only occur by really hard system overloads or wrong usage.

Regards
Matthias Carstens
RME

MC's Website

  • Registered: 2007-05-02
  • Posts: 316

Re: MF/PCI as system audio in W7 64-bit = High latency ASIO

Thanks Matthias. I'll keep an eye out for that.

PC1 = HDSPe PCIe: DF-ADI-8 DS / HDSPe PCIe: MF2
MBP = HDSPe Expresscard: MF1