"We'll just upload it to Azure."
Famous last words from someone who hasn't done the maths on transferring 100 terabytes over the internet.
Let's break down exactly how long it takes to move serious amounts of data to the cloud - and why physical transport is often the only practical option.
The Brutal Maths of Data Transfer
Here's what 100TB looks like across different connection speeds:
| Connection Speed | Theoretical Time | With 25% Overhead | Reality |
|---|---|---|---|
| 1 Mbps | 26 years | 32+ years | Not happening |
| 100 Mbps | 95 days | ~120 days | 4 months |
| 1 Gbps | 9.5 days | ~12 days | Nearly 2 weeks |
| 10 Gbps | 23 hours | ~29 hours | Just over a day |
That "25% overhead" accounts for TCP protocol overhead, packet retransmissions, connection resets, and the reality that you never get 100% of your theoretical bandwidth. In practice, it's often worse.
The Hidden Cost: Network Lockout
Here's what the transfer time doesn't tell you: your network is saturated the entire time.
Uploading at full speed for 12 days means:
- Video calls stuttering or failing
- Cloud apps grinding to a halt
- VPN connections timing out
- Staff productivity tanking
- IT tickets piling up
Most organisations can't dedicate 100% of bandwidth to a data transfer. If you throttle to 50% to keep the business running, double those transfer times. At 25% utilisation, quadruple them.
A "12-day transfer" easily becomes 6-8 weeks of degraded network performance.
The Azure Data Box Option
Microsoft's Azure Data Box solves the bandwidth problem by shipping physical storage devices:
| Device | Capacity | Typical Timeline |
|---|---|---|
| Data Box Disk | 8TB per disk | 1-2 weeks |
| Data Box | 100TB | 2-3 weeks |
| Data Box Heavy | 1PB | 2-3 weeks |
The process:
- Order the device (1-3 days)
- Wait for delivery (3-5 days)
- Copy your data (varies)
- Ship it back (3-5 days)
- Microsoft uploads to Azure (2-5 days)
- Device returned/wiped
Total time: 2-3 weeks minimum for the round trip, often longer.
Data Box is brilliant for planned migrations where you have time. But what if you don't?
When Speed Actually Matters
Some scenarios don't allow for 2-3 week transfer windows:
Data centre exits: Your lease expires in 30 days. The hardware is getting decommissioned. You need data out now.
Disaster recovery: Your primary site is compromised. Backup data needs to reach the DR site today, not next month.
Project deadlines: The new platform goes live in 2 weeks. The data migration is on the critical path.
Compliance requirements: Audit data must be in the compliant storage location by end of quarter.
Facility closures: The building is being sold. Everything must be removed by Friday.
The Physical Transfer Alternative
Sometimes the fastest way to move data is to physically move it yourself.
At Caleta, we've built Data Shuttle specifically for organisations that can't wait weeks for data transfers. We bring enterprise-grade portable storage to your site, copy your data locally at NVMe speeds, then transport it to our Thames Valley data centre for upload via our 10Gbit+ connection.
100TB transferred in 24-48 hours - not 2-3 weeks.
The maths works because:
- Local LAN copy: We bring 10Gbit or even 100Gbit switches with NVMe storage to migrate data as fast as possible from your infrastructure
- Physical transport: 1-2 hours anywhere in the Thames Valley corridor
- Local WAN upload: We use 10Gbit or higher upload speeds from our data centre
This combination makes 100TB transfers achievable in 48 hours - or over a weekend if you prefer minimal business disruption. Get in touch to discuss your requirements.
Compared to alternatives:
- Internet upload: 12+ days (if you can saturate your connection)
- Azure Data Box: 14-21 days (shipping round trip)
International Transfers and the Bandwidth Trap
Transferring to Azure regions outside the UK? Here's where it gets interesting.
Once your data reaches our data centre and hits the Microsoft backbone, we can transfer at 25Gbit and beyond to any Azure region globally. The Microsoft network is incredibly fast between regions.
But here's the gotcha: intercontinental bandwidth charges are expensive. Really expensive.
Transferring 100TB from UK South to East US? That's potentially thousands of pounds in egress charges that catches people off guard. We've seen organisations budget for the transfer service, then get blindsided by the Azure bill.
Before any international transfer, we'll calculate the expected bandwidth costs and make sure you know exactly what you're signing up for. It's a common and expensive mistake that's easily avoided with proper planning.
Choosing the Right Approach
Here's a decision framework:
Use internet upload when:
- Data is under 5TB
- You have 1Gbps+ upload with headroom
- Timeline is genuinely flexible (weeks, not days)
- Network impact is acceptable
Use physical transport (Data Shuttle) when:
- Data is 5TB or more
- You want it done in days, not weeks
- Your network can't handle sustained uploads
- You need white-glove handling and chain of custody
- You're in the UK (especially Thames Valley / M4 corridor)
Consider Azure Data Box when:
- You have 3+ weeks available and no urgency
- You're comfortable managing the device yourself
- Remote UK location where collection isn't practical
Here's the thing: Data Shuttle pricing is comparable to Azure Data Box for most volumes, but you get the job done in 48 hours instead of 2-3 weeks. Unless you genuinely have no time pressure and prefer self-service, faster is usually better.
The Real Cost Calculation
Don't just compare service prices. Factor in:
- Lost productivity from network saturation
- Delayed project timelines if transfer takes longer
- Risk of data centre access expiring mid-transfer
- Staff time managing a multi-week upload
A faster transfer at higher cost often works out cheaper than a "cheap" transfer that drags on for weeks and impacts business operations.
Getting Your Data Moved
Need to move significant data volumes to Azure, AWS, or another data centre? We provide free quotes within 24 hours.
Whether it's 10TB or 100TB+, we'll tell you honestly whether Data Shuttle makes sense for your situation - or if another approach would serve you better.
Based in the Thames Valley, we collect from London, the M4 corridor, and beyond. Get in touch to discuss your data transfer requirements.
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