This is due to changes in the architecture of QEMU that do not fit very well with Windows. In the long term things should get better, but it may take a while and no one is working specifically on Windows performance.
** Changed in: qemu Status: New => Won't Fix -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1252009 Title: slow boot on USB drives Status in QEMU: Won't Fix Bug description: QEMU version: 1.6.90.0 from 2013 11 16 Host OS: Windows XP SP3 x86 Host machine: 3.2 GHz AMD Athlon 64 dual core processor, 4 GB DDR II (3.2 seen by the OS) memory Guest OS: Grub4Dos boot manager menu Problem: when I use "qemu-system-i386.exe -drive file=\\.\PhysicalDrive1,if=ide,index=0,media=disk,snapshot=off -m 512" it boots twice as slow than the 0.15.1.0 version. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1252009/+subscriptions