My Lenovo laptop do not works anymore and returned from repair with a broken monitor / no more boot 
So, I wanted to install Windows 10 (1604 I think) on my MacBook Pro (4 y/o).
The installation process works fine (4GB RAM / 50 GB Disk), but when run, it behave very slow.
My MacBook Pro boot SSD have 20 GB of free space / no other application running / no internet /
What is your experience ?
Exactly the same, so I bought a cheap PC for running Windows software.
I’m running Windows 10 on my MacBook Pro (late 2013) and on my Mac mini (2012) with Parallels Desktop 14 for Mac and is running flawlessly on both machines.
SSD drives ?
Yes, the Mac mini has two 1 TB SSD drives and the MacBook Pro has a 1 TB SSD drive.
Both have 16 GB memory.
Oh.
I have hard time to get some free GB on my internal SSD (250GB), so I set the boot HD on an external one (I even boot on that HD with Sierra, but it is also slow).
The Windows 10 Mouse Cursor is always late and when my Mouse goes outside of the VirtualBox (v6.0.4) window, most of the time I do not realize what happened
MICE (a free Microsoft application to make panoramas from two or more files) flashes the panorama resulting image. PhotoShop also know about creating panoramas, but I do not have it.
That explains it.
Working from an external disc is slow and VirtualBox isn’t the fastest either.
This isn’t going to work smoothly.
Only the newest MacBook Pros that have Thunderbolt 3 are fast enough to work from external discs.
Thansk Paul.
you need at least an usb3 connected external ssd drive.
and 4gb ram for win10 is quite low, I would use 8gb at least.
without ssd, everything is so slooooooooow
ps: and an usb2 connected external ssd is quite as slow as a mechanical drive.
Ah, I see: Has been Kaputt-repaired [English] / Kaputt-repariert [German]
Lenovo European repair plant is in Germany
I use Hyper-V for my vm’s on Windows. Every time I create a new VM the default is 1 CPU core which makes the VM run very slow. Could this be part of the issue here too?
I use Parallels on a quad core MBP. My Windows 7 VM gets by fine with 4gb of RAM and 1 core, but my Windows 10 VM has to have 8gb and 2 cores. The difference is night and day.
Also: I think Windows 10 is slow with a HDD when it’s a real PC and the HDD is on a SATA interface. I would never try to run a Windows 10 VM from an external drive of any kind except maybe Thunderbolt SSD. My VMs are on my internal SSD.
I can say that Windows 10, with enough RAM, cores, and internal SSD storage, runs like a real machine in Parallels. It always feels fast and snappy.