# Backup Window and Throughput Calculator

> Source: https://netray.co/tools/backup-window-and-throughput-calculator
> Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems.
> Section: Free Tools

## Short answer

Calculate full and incremental backup duration from data size, link speed, efficiency and dedupe, and the throughput needed to hit your window.

## Category

erp-operations

## Audience

- IT manager
- Backup administrator
- ERP administrator

## Tool

**Kind:** calculator

**Inputs:**

#### Protected data (full)

**Key:** data_tb

**Type:** number

**Default:** 12

**Min:** 0.1

**Step:** 0.5

**Unit:** TB

#### Daily change rate

**Key:** change

**Type:** slider

**Default:** 3

**Min:** 0.5

**Max:** 20

**Step:** 0.5

**Unit:** %

#### Backup link speed

**Key:** link

**Type:** select

**Default:** 1000

**Options:**

##### 100 Mbps

**Value:** 100

##### 1 Gbps

**Value:** 1000

##### 10 Gbps

**Value:** 10000

##### 25 Gbps

**Value:** 25000

#### Real throughput efficiency

**Key:** eff

**Type:** slider

**Default:** 70

**Min:** 30

**Max:** 95

**Step:** 5

**Unit:** %

**Help:** Protocol overhead, disk speed and contention. 60 to 80 is common.

#### Dedupe and compression ratio

**Key:** reduce

**Type:** number

**Default:** 2

**Min:** 1

**Max:** 20

**Step:** 0.5

**Unit:** x

**Help:** Source-side reduction before data crosses the link.

#### Backup window

**Key:** window

**Type:** number

**Default:** 8

**Min:** 1

**Max:** 48

**Step:** 1

**Unit:** hours

**Outputs:**

#### Effective throughput

**Key:** mbs

**Expr:** link * (eff / 100) / 8

**Format:** decimal

**Description:** MB per second after efficiency loss.

#### Full backup duration

**Key:** full_h

**Expr:** data_tb * 1024 * 1024 / reduce / mbs / 3600

**Format:** hours

**Primary:** true

#### Daily incremental size

**Key:** inc_tb

**Expr:** data_tb * change / 100

**Format:** decimal

#### Incremental duration

**Key:** inc_h

**Expr:** inc_tb * 1024 * 1024 / reduce / mbs / 3600

**Format:** hours

**Primary:** true

#### Window used by incremental

**Key:** win_use

**Expr:** inc_h / window * 100

**Format:** percent

#### Link speed needed for full in window

**Key:** need_mbps

**Expr:** data_tb * 1024 * 1024 / reduce * 8 / (window * 3600) / (eff / 100)

**Format:** decimal

**Description:** Mbps needed to complete a full backup inside the window.

**Chart:**

#### Full backup hours vs link speed (Mbps)

**Type:** line

**X:** link

**From:** 100

**To:** 10000

**Steps:** 30

**Series:**

- full_h

**Disclaimer:** Throughput depends on source disk, backup software and network conditions. Validate with a timed test job.

## Content

**Intro:** A backup that does not finish before the first shift is a backup problem and an ERP performance problem. This calculator estimates how long fulls and incrementals take and how fast the link must be to fit your window.

**Sections:**

#### How to use it

**Body:** Enter the size of data in scope for a full backup and your daily change rate, which you can read from the backup software reports. Choose the link speed that the backup traffic uses, then set a realistic efficiency. If the software does source-side dedupe or compression, enter the observed ratio. Finally enter the time window available. You get the full duration, the incremental duration, how much of the window the incremental uses, and the link speed required for a full in-window.

**Bullets:**

- Use observed dedupe ratios, not vendor claims
- Plan fulls for weekends and incrementals for nights
- Test restore speed separately, it is usually slower

#### The method

**Body:** Effective throughput in MB per second is link speed in Mbps times efficiency divided by 8. Data volume in MB is terabytes times 1,048,576, divided by the reduction ratio because less data crosses the wire. Duration in hours is data divided by throughput divided by 3,600. The required link speed formula inverts this: reduced data in megabits divided by window seconds, then divided by efficiency.

#### Worked example

**Body:** Twelve terabytes with a 2x reduction sends about 6 TB. A 1 Gbps link at 70 percent efficiency moves roughly 87.5 MB per second, so the full takes about 20 hours, which will not fit an 8 hour window. A 3 percent change rate is 0.36 TB, which takes about 0.6 hours, comfortably inside the window. To do the full overnight you would need around 2.4 Gbps, so use weekend fulls or a faster path.

#### Common mistakes

**Body:** Assuming the link is the bottleneck when the source disk or the backup proxy is, running backups while month-end jobs are active, and measuring only backup speed while ignoring restore time. Also check that application-consistent snapshots for the ERP database are taken before the transfer starts, and confirm that offsite copies finish before the next cycle.

**Cta:** If backup logs and ERP job schedules are scattered across tools, Netray can build a private assistant that answers when and why a job overran, on your own infrastructure.

**Faq:**

#### How long does it take to back up 1 TB over 1 Gbps?

**Answer:** At about 70 percent efficiency a 1 Gbps link moves roughly 87 MB per second, so 1 TB takes about 3.3 hours without any dedupe. With 2x reduction it is under 2 hours. Source disk speed can lower this.

#### What is a typical daily change rate?

**Answer:** Transactional ERP databases often change 2 to 5 percent a day, file shares 1 to 3 percent, and engineering or CAD vaults can spike when releases happen. Read the actual figure from your backup reports.

#### Why is my backup slower than the link speed suggests?

**Answer:** Protocol overhead, many small files, slow source disks, encryption, antivirus scans and competing traffic all reduce throughput. 60 to 80 percent of line rate is a common real-world result.

#### Does restore time matter as much as backup time?

**Answer:** Yes, restore speed defines your recovery time objective and is often slower than backup because of random writes and verification. Test a full restore at least once a year and record the time.

## Search terms

backup window calculator, backup time calculator, how long will my backup take, backup throughput calculator, full backup duration estimate, incremental backup size calculator, backup speed over network, nightly backup window sizing

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