Best tuning for qemu windows guest(windows 7)

In your opinion,which is the best tuning for windows 7 guest?
I use
cpu: host

mem: at least 2G,better 4G

disk: this is the most important,without "unsafe" cache is really slow and apply a 1G "service pack" can take 3 hours,with unsafe is really fast,actually I use
cache=unsafe
io=threads
discard mode=unmap
detect zeroes=unmap

network:virtio

controller:all virtio

Any suggestion,opinions?Thanks

with scsi-virtio controller and qemu 3.0 best work with

cache=unsafe
io=threads
discard mode=ignore
detect zeroes=off