If you wonder whether to use IDE or SCSI controllers for your Hyper-V virtual machines, the short answer is: IDE is fine.
There is no need to go for SCSI, it won’t be any faster. Note that you need to have a IDE connected virtual disk in order to boot.
If you want better performance, the virtual machines will run much faster if you:
- Use pass through disks instead
- Use fixed sized VHDs
- Refrain from using snapshots / checkpoints
- Refrain from using dynamically expanding disks
- Have at least 15% free space inside the VM at all times, and at least 10GB free. It’s an old characteristic of NTFS….
- Use paging files on a separate VHD, ideally hosted on a separate drive
- Use fixed-sized paging files
- Use 4KB NTFS cluster size on the host
Yes, from the performance side, a VM with IDE drives needs less processing to emulate IDE than using SCSI. Otherwise, in my experience, I did not have any breaks in using SCSI on Windows machines over using IDE. However I must say that during synthetic benchmarks, SCSI seems to be a little faster than IDE on Hyper-V.