Whitepaper
NAS and network drives on your Mac: SMB, Time Machine and speed
A Synology, QNAP or UGREEN NAS in the closet, or a shared folder on your partner’s Windows PC: your Mac handles all of that, just not always as smoothly as you’d like. Folders that take ages to open, a Time Machine backup that suddenly wants to start over, a drive that’s gone after a restart. In this whitepaper from the series “Mac and the rest of the world” we go through how to connect a network drive to your Mac properly, what changed in macOS Golden Gate, and how to fix the usual problems.
Connecting through Finder
The quickest route is Go > Connect to Server in Finder, or Command-K. Type the address of the NAS or PC, for example smb://192.168.1.20 or smb://your-nas-name.local. Log in with a user that exists on the NAS, pick the shared folder, and it shows up as a drive in Finder and on your desktop.
Add the address to your favorites with the plus button and save the password in your keychain. Prefer the IP address over the Network list in the sidebar, which isn’t always reliable.
A shared folder on a Windows PC works exactly the same way. You log in with that PC’s user, often the email address of the Microsoft account.
AFP is gone, SMB is what’s left
For years the Mac had its own protocol for network drives, AFP. Apple’s support page on Time Machine backup disks says AFP isn’t supported in macOS 27 or later. So an old AirPort Time Capsule no longer works as a backup disk either. If your NAS still has an AFP share, move it to SMB.
SMB is the Windows protocol and by now the standard on the Mac too. Set the maximum version on your NAS to SMB3 and turn off the old, insecure SMB1.
Packet signing and slow folders
The best known complaint about SMB on the Mac is speed, especially with folders holding thousands of files. One of the causes is packet signing: every packet gets a digital signature against tampering. That costs processing power, particularly on a NAS with a low-power CPU.
You can turn signing off on the Mac side with a text file /etc/nsmb.conf containing:
[default]signing_required=no
Then disconnect the share and connect again. Running smbutil statshares -a in Terminal shows whether signing is active. Apple itself says to do this only on a network you trust. At home that’s defensible, at the office it isn’t. If the server requires signing, this file changes nothing. What I couldn’t pin down: whether macOS 27 really sped up large folder listings (forum users disagree), and whether Apple has new nsmb.conf advice. Apple’s article on it is archived. So test it yourself and drop the file if it makes no difference.
Mounting automatically at login
A network drive doesn’t stay connected after a restart. Mount the share in Finder first, then open System Settings > General > Login Items and add the mounted drive with the plus button. Your Mac then reopens it at login, using the password from your keychain. Away from home, just dismiss the error message.
Time Machine to a NAS
Time Machine can back up to a NAS that supports Time Machine over SMB. Synology, QNAP and UGREEN all do. On the share Time Machine creates a sparsebundle for each Mac, a disk image made up of thousands of small pieces.
Setting it up
- Synology (DSM 7): create a separate shared folder and a separate user for Time Machine. Put a quota on that folder, which works per folder on a Btrfs volume. Go to Control Panel > File Services, turn on SMB, and under the advanced settings enable Bonjour and the Time Machine broadcast via SMB, then select your folder. Synology advises against enabling the recycle bin or using an encrypted shared folder for Time Machine.
- QNAP (QTS or QuTS hero): create a shared folder, mark it as the Time Machine folder in the settings, set the highest SMB version to SMB3 under Microsoft Networking and create a dedicated user.
- UGREEN (UGOS Pro): according to UGREEN this works over SMB from firmware 1.9.0.0035. Turn on SMB in the file services and give the Time Machine folder a capacity quota.
On the Mac, open System Settings > General > Time Machine and add a backup disk. If the NAS isn’t listed, mount the share in Finder first. Turn on encryption.
How reliable is it?
Reasonably, but less so than an SSD attached to your Mac. If the connection drops during a backup, or your MacBook goes to sleep halfway through a write, the sparsebundle can get damaged. Time Machine then wants to create a new backup and your old history is gone. Not often, but often enough to plan for. Set the quota to roughly two to three times the amount of data on your Mac, and make sure the NAS itself is backed up too, off site or to the cloud.
Search, hidden files and file names
Spotlight doesn’t index network shares the way it indexes your internal drive. Searching a share in Finder is therefore slow, unless the server itself offers Spotlight search over SMB. Samba can, but I couldn’t confirm it for Synology or QNAP.
.DS_Store files are where Finder remembers how a folder looks. Windows users do see them. Run defaults write com.apple.desktopservices DSDontWriteNetworkStores -bool true in Terminal, log out and back in, and your Mac stops writing them to network drives. There’s more on this in our whitepaper on hidden Mac files.
File names can cause trouble as well. A colon or a question mark is fine on the Mac but not on Windows. On a NAS such a file shows up with a strange name or not at all. More in our piece on zip, rar and file names.
Reaching your NAS from outside
Never open ports for your NAS on your router, and certainly not SMB port 445. NAS devices are a favorite ransomware target. There are safer routes:
- QuickConnect from Synology or myQNAPcloud from QNAP, through the manufacturer’s servers.
- Tailscale, a VPN as a package on Synology and QNAP and an app on your Mac and iPhone. Reachable from anywhere with no open ports. For most people the safest and easiest option.
Synology Drive and Qsync
If you want files synced locally, like iCloud Drive, use the manufacturer’s app. According to Synology, Synology Drive Client has run natively on Apple silicon since version 3.2. QNAP has Qsync for Mac 6.0 in beta in 2026 as a universal app. I couldn’t confirm whether a final release is out yet, so check QNAP’s download page.
Wi-Fi or cable
A NAS is only as fast as the network in between, and a hard drive in the NAS often manages just 150 to 250 MB/s itself. Ballpark figures:
| Connection | Realistic | Good to know |
|---|---|---|
| Wi-Fi 6 or 6E | Varies a lot, often 40 to 120 MB/s | Depends on distance, walls and congestion. Fine for documents, so-so for video. |
| Gigabit Ethernet | About 110 MB/s | Stable. Ideal for Time Machine. |
| 2.5 GbE | About 280 MB/s | Cheap USB-C adapters. Your switch and NAS need to support it too. |
| 10 GbE | Up to about 1 GB/s | An option on Mac mini and Mac Studio, otherwise a Thunderbolt adapter. Only worth it with SSDs or many drives in the NAS. |
Common problems and fixes
| Problem | Fix |
|---|---|
| NAS doesn’t show up in Finder | Connect directly with smb:// and the IP address. Turn on Bonjour on the NAS. |
| Old share stopped working after updating to macOS 27 | Probably AFP. Turn on SMB on the NAS and reconnect. |
| Large folders open slowly | Use a cable, check for SMB3, test signing off via nsmb.conf on a trusted network. |
| Time Machine can’t see the NAS | Check that the folder is set as a Time Machine folder. Mount the share manually first. |
| Time Machine wants to start over | The sparsebundle is damaged. Accept the new backup and keep a second backup on a local drive. |
| Windows colleagues see .DS_Store and ._ files | Turn on DSDontWriteNetworkStores. Clean up ._ files with dot_clean. |
What fits you
You only want to share files at home
A shared folder over SMB, mounted at login.
You want Time Machine for several Macs
A NAS with a Time Machine folder and a quota per Mac. Put the NAS on a cable, and keep an SSD as a second backup for your most important Mac.
You work with large video or photo files
Cable, at least 2.5 GbE, and a NAS with SSDs or an SSD cache. Or work locally with Synology Drive or Qsync.
Step-by-step plan
- On the NAS, check that SMB is on, with SMB3 as the highest version and SMB1 off. Move any AFP shares to SMB.
- Create your own user on the NAS and don’t use the admin account.
- On your Mac, connect via Go > Connect to Server with
smb://and the IP address, and save the password in your keychain. - Add the share to Login Items if you always want it available.
- Create a separate Time Machine folder with a quota and turn on encryption in Time Machine.
- Stop .DS_Store files from being written to network drives if you share the NAS with Windows users.
- If it’s slow, try a cable first and only then test with signing off.
- Set up remote access through Tailscale or QuickConnect and check that no ports are open on your router.
And with Apple?
Apple no longer sells network storage, and with macOS 27 the Time Capsule is written off too. Apple points you to iCloud Drive for files and an external drive for Time Machine. An external APFS SSD is the most reliable Time Machine backup: fast, no network, and no sparsebundle that can break. iCloud Drive works everywhere, but you pay monthly and it’s syncing, not a backup. A NAS sits somewhere in between: more hassle, but everything stays in your own home. Whatever you choose, one backup is no backup.
This whitepaper describes the situation in October 2026, with macOS Golden Gate (macOS 27), DSM 7, QTS 5 and UGOS Pro. Menus on your NAS can differ between versions, so check the manufacturer’s manual if in doubt.
This article is part of the Mac and the rest of the world series, where you’ll find every part in one place.