Hello, i`m using a Emu 0404 USB with Winxp SP3 and found strange, Driver related issues.
As EMU states it`s Products are for Professionals > i`m one of these guys
So lets go:
I`ve found out that the EMU 0404 USB (latest Drivers & firmware are installed, usb port where the 0404 is connected not changed since installation) uses high CPU % for DPC`s (deferred procedure calls).
It`s been tested with 3 different Pc`s. Two were using Intel ICH7 Chipset for the USB part and i`ve also tested it with a Intel ICH8 (there was no irq sharing!)
* Grapicscardacceleration was set to stage 1 in advanced display settings.
* Lan, Wlan, Cdrom, Esata, Motherboard Onboard Audiochip etc. > disabled
No problems shown in DPC Latency Checker tool!! latency is low
But and here is the issue:
Sysinternals Process Explorer clearly shows, that the CPU load for DPC`s is going up to 10-15% when playing ASIO audio through the EMU 0404 USB. dpc latency is also going up a little bit which is normal instead of the 10-15% cpu load.
If i open the Sequencer (also tested with different sequencers + winamp using asio) the CPU load for DPC`s is going nuts!
So it`s not relevant if audio is playing or not! The DPC stuff starts when the usb 0404 is set up for playing audio by any audiosoftware.
Normally the CPU load for DPC`s at all three pc`s is between 0,7 - 2,6%.
I`ve additionaly tested with a firewire interface Motu 828mk3 where the DPC`s CPU load is going to a overall maximum of 3,3% when playing audio!
So something is going wrong here. see attached picture
@ ALL >>> wan`t to check on your pc?
1) download Sysinternals Process Explorer v15.13 (Standalone no installation required
2) check the dpc`s cpu load in process explorer while no audiosoftware is running.
it should be near to 0-3% (peaks) otherwise your pc has another problem
3) start any audiosoftware using the 0404 usb asio drivers and watch the dpc`s cpu load again