What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Limit backup traffic at the narrowest setting your NAS offers—ideally on the individual backup job—then confirm that the job still finishes within its backup window. A bandwidth cap can ease congestion, but it also slows transfers and may leave newer data unprotected if a run cannot complete. There is no universal “safe” cap: the right setting depends on the NAS software, task, destination, transfer direction and time available.
Choose the right kind of bandwidth control
Before changing a limit, identify what traffic it governs. A job-level cap is usually the most targeted choice; a service-level rule may affect every task using that service, while an appliance-wide rule can affect backups, restores and management traffic too.
As an Amazon Associate I earn from qualifying purchases.
| Control scope | What it can limit | What to check |
|---|---|---|
| Backup-job setting | A particular job, often in one or both transfer directions | Whether the job supports upload, download, and time-window settings for its destination |
| Service-level setting | Traffic associated with a service such as rsync | Whether the rule applies to all service traffic, and whether it overrides user or group limits |
| Appliance-wide rule | Traffic across the NAS or appliance, potentially including multiple interfaces and services | Whether other jobs, restores, downloads, or UI operations share the same capacity |
Also determine whether the constrained direction is upload, download, or both. A remote backup commonly sends data out of the source NAS, while a restore brings it back; limiting only one direction will not necessarily control the other.
Set a limit in the backup application where possible
Synology DSM and Hyper Backup
Synology’s DSM service-traffic guidance lists a Hyper Backup task setting at Hyper Backup > Task Settings > Settings > Bandwidth Limitation. Labels and availability can vary by DSM build and destination, so check the task’s current settings in your own installation. The guidance distinguishes this per-task control from DSM Traffic Control and service-specific limits. Synology’s DSM service traffic guide
#1 Best Overall
- IronWolf internal hard drives are the ideal solution for up to 8-bay, multi-user NAS environments craving powerhouse performance
- Store more and work faster with a NAS-optimized hard drive providing ultra-high capacity up to 16TB and cache of up to 256MB
- Purpose built for NAS enclosures, IronWolf delivers less wear and tear, little to no noise/vibration, no lags or down time, increased file-sharing performance, and much more
- Easily monitor the health of drives using the integrated IronWolf Health Management system and enjoy long-term reliability with 1M hours MTBF
- Three-year limited warranty protection plan included and three year Rescue Data Recovery Services included
Synology Knowledge Center warns: “For optimal performance, we recommend avoiding setting up bandwidth limits for Hyper Backup.” That is performance advice, not a ban on limiting traffic. If protecting other users or services requires a cap, account for the longer backup and restoration times and verify that runs complete. Synology’s troubleshooting guidance covers DSM 7 series and legacy versions and was last updated September 18, 2026. Synology’s Hyper Backup speed troubleshooting guide
QNAP HBS 3
HBS 3 documentation describes a Use rate limits option for backup jobs, with a maximum upload limit and operating time. One-way sync jobs have documented maximum upload and download limits and an operating time. The available policies depend on job type and destination, so use the controls presented by the current job wizard rather than assuming every task has the same options. QNAP HBS 3 backup-job policies and QNAP HBS 3 one-way sync policies
Rank #2
- Store more, compute faster, and do it confidently with the proven reliability of BarraCuda internal hard drives
- Build a power house gaming computer or desktop setup with a variety of capacities and form factors
- The go to SATA hard drive solution for nearly every PC application from music to video to photo editing to PC gaming. Ax. Sustained transfer rate OD: 190MB/s
- Confidently rely on internal hard drive technology backed by 20 years of innovation
- Frustration Free Packaging - This is just an anti-static bag. No cables, no box.
Do not treat synchronization as interchangeable with backup. A sync can mirror changes, including deletions, whereas a versioned backup is intended to preserve recoverable points in time. QNAP’s HBS 3 version 17-or-later quick-start guide distinguishes the job types and notes that a QNAP NAS destination uses the RTRR server for backup jobs; sync destinations may use RTRR or rsync. HBS backup data is stored in .qdff folders and can be restored through HBS or extracted with QNAP’s QuDedup Extract Tool. QNAP HBS 3 quick-start guide
Use broader limits only when their wider effects are acceptable
DSM service controls and rsync
DSM Traffic Control and application-level settings are not the same thing. Synology’s rsync guidance describes a speed limit that can be enabled, scheduled, or disabled; it is server-wide for rsync and can override individual or group settings. That does not mean it controls every Hyper Backup destination: confirm that the traffic actually uses rsync before relying on this rule. The cited rsync documentation is for DSM 6, and localized menu wording may differ from your current DSM version. Synology’s rsync service guide
Rank #3
- IronWolf internal hard drives are the ideal solution for up to 8-bay, multi-user NAS environments craving powerhouse performance.date transfer rate:6.0 gigabits_per_second
- Store more and work faster with a NAS-optimized hard drive providing 8TB and cache of up to 256MB
- Purpose built for NAS enclosures, IronWolf delivers less wear and tear, little to no noise/vibration, no lags or down time, increased file-sharing performance, and much more
- Easily monitor the health of drives using the integrated IronWolf Health Management system and enjoy long-term reliability with 1M hours MTBF
- Three-year limited product warranty protection plan and three year Rescue Data Recovery Services included
ActiveProtect Manager
In Synology ActiveProtect Manager 1.2, bandwidth rules can target IP addresses, ranges, subnets, or public IPs and apply to inbound and outbound traffic across interfaces and ports. The configured total bandwidth is shared evenly among jobs processing at the same time. The rule can therefore affect not only backup jobs but also backup copies, restores, downloads, and UI operations; include those uses when assessing a cap. Synology ActiveProtect Manager traffic control
Set a cap the backup can live with
- Record the task and its constraints. Note the NAS operating system and version, backup application, job type, destination, transfer direction, and the time by which the run must finish. Distinguish an initial or full backup from later runs.
- Choose the narrowest suitable control. Look first for a rate limit or operating schedule in the backup job. If none is available, investigate service-level or appliance-wide controls and establish which other traffic they will affect.
- Plan around capacity and the backup window. Start with a conservative cap that leaves capacity for other users while allowing time for the data being protected to transfer. This is a planning approach, not a vendor-prescribed rate: the cited vendor guidance establishes no universal cap or threshold.
- Allow for changing data and full runs. A limit that works for a small routine run may not leave enough time for an initial backup or a cycle with a larger volume of changed data. If a job routinely overlaps the next scheduled run, revise the cap, schedule, or job design rather than assuming the backlog will resolve itself.
- Check results over multiple cycles. Review each job’s completion status and error logs after changing the setting. For a critical backup, perform a restore check as an operational safeguard; a rate limit alone does not establish that backup data is recoverable.
When a backup is slow, diagnose before lowering the cap
Transfer rate is not the only possible bottleneck. Synology says Hyper Backup chunks and deduplicates data, indexes it, and constructs backup structures, so its progress may not resemble a simple file copy. If a run is slow even without a limit, check the following before reducing bandwidth further:
Rank #4
- Available in capacities ranging from 2 to 22TB(1) | (1) 1GB = 1 billion bytes and 1TB = 1 trillion bytes. Actual user capacity may be less depending on operating environment.
- For RAID-optimized NAS systems with unlimited number of bays
- Rated for 550TB/yr workload rate(2) | (2) Annualized Workload Rate = TB transferred x (8760 / recorded power-on hours). The maximum rated workload is specified for operating at typical temperature of 40C. Workload Rate will vary depending on your hardware and software components and configurations.
- Designed to handle the demands of high-intensity 24x7 multi-user NAS environments
- Western Digital partners with a wide range of NAS system vendors for extensive testing to ensure compatibility with most NAS enclosures
- NAS health: Review storage-pool and volume status, along with CPU use.
- Task shape: A task containing many files can take longer to process; Synology suggests considering a split into smaller tasks when several shared folders contain many files.
- Schedule: Moving a run to an off-peak period may reduce competition for network or NAS resources without imposing a tighter cap.
- Destination and path: Consider whether the destination, protocol, or network path is the limiting factor. A local copy, remote NAS, cloud destination, and third-party service do not necessarily behave alike.
For a remote Synology destination specifically, Synology’s troubleshooting guidance calls out Traffic Control rules for Hyper Backup Vault or port 6281, and an MTU default of 1500 on both NAS devices. Treat these as configuration-specific checks, not settings to change blindly; confirm that they apply to your connection and configuration before adjusting them. Synology’s Hyper Backup speed troubleshooting guide
Recommended Free Tools
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
