I’ve been restored my current MacBook Pro (1 TB) from time machine successfully almost ~100 times by now. I’m looking to buy a new MacBook Pro with M1 chip, and started to think 256 GB storage is perfect for me because I only use about 100GB of disk space. It’s faster for me to backup/restore from a smaller backups. If I decided to buy a new Mac that have only 256GB instead of 1 TB MacBook, will I lose any of the performance advantages?
There are some slight disadvantages of a smaller drive.
The time to restore from backup will not change depending on the drive's size, only on the quantity of data stored on it, subject to 2. below.
Smaller drives get full more easily [obviously] & you can't upgrade the drive on a modern Mac, so you'd have to use an external.
Full drives are slower to read/write. This is mainly to do with how drives erase & re-use sectors after they are 'empty'. The system periodically cleans up unused sectors using a method known as TRIM. A sector marked as 'trimmed' can be written to immediately. A sector which hasn't yet been 'trimmed' first needs to be erased. This is quite a bit slower.
Smaller drives wear out more quickly as they have less ability to spread out their writes to unused portions of the drive.
If you have limited RAM, then virtual memory is subject to both factors 1 & 2, as it needs to be able to read & write to the drive frequently.