1 (edited by radiation 2010-02-14 20:19:07)

Topic: Windows 7 DPC latency problem

Hi guys

I have very high latency as you can see here :

Windos XP :
[img align=c]http://i191.photobucket.com/albums/z303/GEORGEVASILAS/WindowsXp.jpg[/img]

Windows 7 :
[img align=c]http://i191.photobucket.com/albums/z303/GEORGEVASILAS/Windows7.jpg[/img]

My system is:

Model : Intel(R) Core(TM)2 Extreme CPU X9650  @ 3.00GHz

Mainboard : Gigabyte Technology EP45T-EXTREME

Memory Module(s)
Memory Module : Golden Empire CL7-7-7 1GB DIMM DDR3 PC3-10700U DDR3-1334 (7-7-7-24 4-33-10-5)

Video System
Adapter :ATI Radeon HD 4870 X2  (1GB, PCIe 2.00 x16, PS3.0, VS3.0)

Storage Devices
WDC WD740ADFD-00NLR1 74GB (SATA150, NCQ, 16MB Cache) : 69GB (C:)
WDC WD5000ABPS-01ZZB0 500GB (SATA300, 3.5", 5400rpm, NCQ, 16MB Cache) : 466GB (D:)
WDC WD3200YS-01PGB0 320GB (SATA300, 3.5", 7200rpm, NCQ, 16MB Cache) : 298GB (E:)
PIONEER DVD-RW  DVR-216D (SATA150, DVD+-RW, CD-RW, 64kB Cache) : N/A (G:)

FireWire/1394 Controller 1 : VIA VT6306 VIA Fire II IEEE-1394 OHCI Link Layer Controller
FireWire/1394 Controller 2 : Giga-Byte TSB43AB23 1394a-2000 OHCI PHY/link-layer Controller

I have installed fut_win_fire400 1.67, 1.69, 1.70
And w2fire_2993, 2998, 29991,29992
I did tests between the drivers and firmware but i still have the same problems on Windows 7 x86 & x64 and Vista x86 & x64.

I've tried the following already:

- updated Win7 til the latest patches
- setting windows for performance (no aero or anything)
- changing to the FW legacy driver (went back and forth with the different drivers a few times)
- different buffers (from 256 to 1024 samples)
- different rates (44, 48, 96)
- enabling/disable "Allow applications to take exclusive control..." on the playback settings of windows sound properties.
- installing/reinstalling latest and previous NVidia Geforce drivers for the 9800GT
- disabling write cache on the hard drives
- setting all power options to performance (never turn off anything)
- disabling Realtek HD audio (on board sound)
- Go to the run box and type regedit Go to the hive: HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/Audiosrv
  In the DependOnService remove all entries except RpcSs and then restart your computer.

So is there enybody with the same problem solved?
Anyone from RME?
What is the secret of Windows Xp and it works so smooth without crackles and pauses?


Re: Windows 7 DPC latency problem

I'd try disabling the LAN adaptors, try using a standard VGA video driver (the Microsoft one), and also try to disable anything else such as DVD-RW, Card Readers, etc etc until you find the culprit.  The nVidia drivers seem OK on my 64-Bit W7 Desktop...

FWIW - I have NEVER been able to get W7's DPC's quite as low as XP's (XP is generally around 10us, and W7 is generally around 30us on the same system with similar optimizations), and I also seem to have better low-latency ASIO performance @ 32-samples under XP (scales better).  Go figure.  I gladly run W7 on my mixdown PC, but my tracking DAW's still run XP for now (until I can get W7 to match XP's performance @ 32-samples).  Either way, W7 blows Vista out of the water for Audio IMO...

Keep on troubleshooting until you find the culprit - I'd also be VERY curious if you could do some XP/W7 comparisons at low latencies once you get W7 all ironed out :-)


2x SSL Alphalink MADI AX
2x Multiface / 2x Digiface /2x ADI8

3 (edited by radiation 2010-02-16 02:06:02)

Re: Windows 7 DPC latency problem

Thank you Randyman

I tried everything..disconnecting everything except mouse and keyboard...i have spend more than 2 months switch between Os but nothing....I bought i VIA pci to Firewire controller...still nothing... Tomorow i get 2 VGA one by Nvidia and one ATI...
As i was looking in the internet i've found this:
Tried it but nothing...
Also this:
Ati bug
Still nothing...
Please let me know if you got somethig i've mist because my english is not that good.

4 (edited by Randyman... 2010-02-16 02:17:54)

Re: Windows 7 DPC latency problem

Are you simply "disconnecting" or actually DISABLING these components from the Device Manager?  Use the Device Manager to disable the previously mentioned devices (LAN/WiFi/Firewire/DVD-RW/Card Readers, etc) and see if your DPC latencies come down.  WiFi seems to be a repeat offender.

One thing I noticed, you are runing an "x2" video card which is basically 2 GPU's in SLI/Crossfire mode - I have never used such a config, but is there any chance this could cause DPC issues (asking the question in general, as I don't know the answer)...


2x SSL Alphalink MADI AX
2x Multiface / 2x Digiface /2x ADI8

5 (edited by radiation 2010-02-16 13:36:54)

Re: Windows 7 DPC latency problem

I don't have any wireless, only a usb printer, mouse, keyboard, and a NI Audio control, and there are all disconnected and i have also disabled many others from Device Manager...
This is my VGA and it is not sli or anything it has dual GPU.

Re: Windows 7 DPC latency problem

do you have ACHI mode on in the bios for the Win 7 install?

Re: Windows 7 DPC latency problem

Yes I think I can help you, been hunting these issues down for clients,
You can read the info here for now, you probably fall in this category with your card as well :


Re: Windows 7 DPC latency problem

Hi, have you tried looking on cpu usage while your daw is stopped?
i've just write this thread


i would like to know if we are talking about the same thing

Re: Windows 7 DPC latency problem

No tigerman this is not the same issue at all.