I have just copied 138 MByte (800 files) from a disk-on-key in 75 sec. This is ~14.7Mbit/s, which is more than USB 1.1 full-speed. I have checked it using KVM and WinXP guest. With QEMU only (-no-kvm), it took 130 sec, which is ~8.5 Mbit/sec. If you can give some info about your USB device (configurations, interfaces, endpoints etc.) and the transfers (isochronous? bulk?) , it would help in solving this issue. ________________________________
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Sunday, November 25, 2007 5:54 PM To: qemu-devel@nongnu.org Subject: Re: [Qemu-devel] USB performance Question Thanks Arnon. USB1 works really great even for complex streaming cameras! Although it is just very very slow. As mentioned I only get about 10kbit/s! which is something I dont understand why. I would have expected 1Mbit/s and could live with that. If there are any test you want me to do please dont hesitate. Cant wait for your USB2 implementation. Great effort! Arnon Gilboa wrote: I am in the middle of coding EHCI (USB 2.0) host controller emulation. It is supposed to support faster device speeds (480 Mbit/sec instead of USB 1.1 speeds - 1.5 or 12Mbit/sec). I will post it on the list when it basicly supports simple devices such as disk-on-key. Currently I still have some major problems with the scheduling of async and periodic frame lists. I will check your comment regarding the speed and see what can be done. Anway, if you want to try to solve the issue yourself, the relevant code is in usb-linux.c (Linux host USB redirector) and the USB UHCI/OHCI controller emulations (hw/usb-uhci.c or hw/usb-ohci.c). -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Sunday, November 25, 2007 3:01 PM To: qemu-devel@nongnu.org Subject: Re: [Qemu-devel] USB performance Question Does anyone have a comment about this? It would be interesting to know where the USB development is going as it is extremely promising and the only small obstacle (i.m.o) for full feature device access. The only remaining barrier is speed which should be improved. I can look at the code if someone can point me to where in the sources the USB interface is. thanks [EMAIL PROTECTED] wrote: I could get very complicated USB devices to work under Qemu with Windows as guest, Linux as host. This is pretty amazing development and I must congratulate the Qemu developers. The only problem is the USB speed. I get only about 10kbit/s max! This is measured by downloading a 1MByte scientific camera image. Is this the expected USB speed at the moment or is there anything I can do to improve speed? Thanks
