Hello I have a very difficult problem with USB audio devices on WindowsXP. I have many(up to 16) USB soundcards (based Micronas UAC3556b) working simultaneously. For low latency I used the DirectKS. When I connected the devices through USB2.0 I got the high CPU usage (up to 100%) in the DPCs of the System process. So, I disabled Enhanced USB controller, soundcards reconnected to the USB universal host controllers and the CPU usage went down to ~15%. Now I have another problem. Removing the working soundcards cause the 100% CPU usage in the System process. The Windows hangs up. if I connect soundcards to USB2 controller (the lower count) I can remove the working soundcards and Windows doesn't hangs. Pls help Best regards Felix Teplitsky ********************************************************************************************** This message (including any attachments) issued by RAFAEL- ADVANCED DEFENSE SYSTEMS LTD. (hereinafter "RAFAEL") contains confidential information intended for a specific individual and purpose, may constitute information that is privileged or confidential or otherwise protected from disclosure. If you are not the intended recipient, you should contact us immediately and thereafter delete this message from your system. You are hereby notified that any disclosure, copying, dissemination, distribution or forwarding of this message, or the taking of any action based on it, is strictly prohibited. If you have received this e-mail in error, please notify us immediately by e-mail mailto:lawraf@xxxxxxxxxxxx and completely delete or destroy any and all electronic or other copies of the original message and any attachments thereof. **********************************************************************************************