Thunderbolt 3 and solid state drives (SSDs) are two high-speed data transfer technologies used in computing. Thunderbolt 3 is an interface that allows connection of peripherals to a computer, while SSDs are a type of high-performance storage drive.
Thunderbolt 3 has a maximum theoretical transfer speed of up to 40 Gb/s (5 GB/s). It uses the USB-C connector and is compatible with a wide range of peripherals including external GPUs, RAID arrays, and high-resolution displays.
SSDs use flash memory and have much faster read/write speeds compared to traditional hard disk drives (HDDs). High-end SSDs like the Samsung 980 Pro have sequential read speeds up to 7,000 MB/s and write speeds up to 5,000 MB/s.
There is an ongoing debate whether the interface speed of Thunderbolt 3 or the drive speeds of high-performance SSDs represent the bigger bottleneck when transferring large files. This article examines real-world speeds of Thunderbolt 3 versus SSDs.
Thunderbolt 3 Overview
Thunderbolt 3 was developed by Intel and uses the USB Type-C connector. It provides up to 40 Gbps of bandwidth for both data transfer and video output 1. The Thunderbolt 3 specification allows for up to 4 lanes of PCI Express 3.0 data, resulting in a maximum bandwidth of 32 Gbps for Thunderbolt 3 devices that don’t support DisplayPort 1.2 2. With the inclusion of DisplayPort 1.2 support, Thunderbolt 3 can provide full 40 Gbps bandwidth.
SSD Overview
A solid state drive (SSD) is a storage device that uses flash memory chips to store data instead of any moving mechanical parts. SSDs were designed to replace traditional spinning hard disk drives (HDDs) which have moving read/write heads. The lack of moving parts gives SSDs significant advantages over HDDs:
- Faster access times and data transfer speeds
- Lower latency, which improves system responsiveness
- Higher reliability with less risk of mechanical failure
- Lower power consumption, longer battery life in laptops
- Resistant to physical shocks and vibrations
Current consumer SSDs like the Samsung 970 Pro can achieve sequential read/write speeds up to 3,500 MB/s, which is nearly 6 times faster than traditional hard drives. However, real-world speeds vary based on capacity, interface (SATA vs. NVMe), and workloads. SSDs enable much faster boot times, game/app loading, and workflow productivity compared to HDDs.
Real-World Thunderbolt 3 Speeds
Despite its theoretical maximum bandwidth of 40 Gbps, real-world Thunderbolt 3 speeds are often lower due to various factors like cable length and device capabilities. Actual throughput depends heavily on the workload and type of device connected.
Thunderbolt 3 uses active cables that can degrade performance over longer lengths. Bandwidth is reduced to 30 Gbps over 0.5-1m cables, 20 Gbps over 1-2m, and 10 Gbps over longer cables (Source). Shorter cables result in faster speeds.
The devices connected also play a major role. SSD storage can utilize more bandwidth than mechanical hard drives. Displays and other peripherals often do not require the full potential speeds. Bidirectional traffic further reduces throughput.
In real-world usage, Thunderbolt 3 typically provides between 1,250-2,500 MB/s for high-performance storage workloads when ideal conditions are met. For less demanding workloads involving a mix of peripherals, speeds are often lower but still faster than alternative interfaces (Source).
Real-World SSD Speeds
SSD speeds in the real world are affected by several factors, such as the controller and NAND type. Manufacturers often quote maximum theoretical speeds, but sustained real-world speeds are typically lower.
Typical SATA SSD sustained read/write speeds are in the 500-550 MB/s range for sequential transfers. Maximum speeds may be quoted at 550+ MB/s for high-end models, but sustained transfers average lower.
NVMe SSDs can achieve higher theoretical throughput over PCIe, often quoted at 3,000+ MB/s. However, sustained real-world speeds for many NVMe drives average 1,500-2,500 MB/s for reads and 500-1,000 MB/s writes. Workloads like small random I/O see smaller gains from NVMe.
Overall, while NVMe SSDs are faster, both SATA and NVMe SSDs offer significant real-world speed improvements over hard disk drives. For typical consumer workloads, a SATA SSD often provides adequate performance.
Sources:
https://www.reddit.com/r/buildapc/comments/9w5qit/how_big_of_a_realworld_difference_is_a_nvm/
Workloads and Use Cases
Thunderbolt 3 and SSDs each offer advantages for certain use cases and workloads:
For media production, Thunderbolt 3 provides extremely fast transfer speeds that allow handling high-resolution video footage smoothly. The bandwidth of Thunderbolt 3 enables seamless editing and rendering of 8K and 4K footage (source).
SSDs offer enormous benefits for gaming thanks to their very low access times. This allows your game’s assets to load much faster from an SSD compared to a hard drive. However, for maximum transfer speeds with huge game install sizes, a Thunderbolt 3 SSD can enable even faster load times (source).
For quickly transferring large files like backups, raw photo/video footage, or project archives, Thunderbolt 3’s 40Gbps bandwidth is extremely useful. An SSD connected via Thunderbolt 3 provides throughputs comparable to an internal NVMe SSD.
In general, Thunderbolt 3 and SSDs complement each other. Thunderbolt 3 provides the interface for extreme speeds, while SSDs deliver the storage performance to fully utilize that bandwidth. Together they offer low latency and high throughput for demanding workflows.
RAID Configurations
Thunderbolt 3 provides the ability to daisy chain up to 6 devices together. This allows multiple drives to be connected, enabling more advanced RAID configurations for improved performance.
For example, RAID 0 stripes data across multiple drives. This allows reads and writes to be distributed across drives for faster overall throughput. With two 1TB SSDs in RAID 0, you essentially have 2TB of storage with double the throughput of a single drive.
According to ThunderBay 4 mini with Thunderbolt 3, their 4-bay Thunderbolt 3 enclosure configured with RAID 0 can deliver over 2400MB/s read and 1900MB/s write speeds when populated with fast NVMe SSDs. This showcases the performance potential of RAID over Thunderbolt 3.
However, RAID 0 offers no data redundancy. So a single drive failure would result in full data loss. RAID 5 or RAID 10 are better options that provide a balance of speed and redundancy when using multiple Thunderbolt 3 SSDs.
New Standards
Emerging standards like PCIe 4.0, USB4, and Thunderbolt 4 are pushing the limits of speed for external devices. PCIe 4.0 offers double the bandwidth of PCIe 3.0, with theoretical transfer speeds up to 16 GT/s per lane compared to 8 GT/s for PCIe 3.0.[1] USB4 builds on Thunderbolt 3 technology, also theoretically doubling bandwidth to 40 Gbps from 20 Gbps.[2] Thunderbolt 4 further evolves the Thunderbolt standard, reaching speeds up to 40 Gbps while introducing mandatory data security requirements.
These new standards point to a future where external storage devices like SSDs can reach ever faster real-world speeds. However, current SSDs are not yet fully saturating the bandwidth of PCIe 3.0. As SSD technology continues advancing, these new standards will provide plenty of headroom for blazing external transfer speeds.
Conclusion
While Thunderbolt 3 has impressive theoretical bandwidth and speeds, many real-world benchmarks and tests demonstrate SSDs with comparable or even faster performance for typical workloads.
Thunderbolt 3 offers up to 40Gbps bandwidth vs 6Gbps max for SATA SSDs, but actual SSD speeds top out around 3.5Gbps for the fastest NVMe models. For small file transfers or single drive access, Thunderbolt 3 bandwidth matters less.
SSD speeds excel at random access across many small files, thanks to fast seek times. Their parallel performance surpasses Thunderbolt 3 storage arrays for many productivity use cases. Compressing or reading many small media files favors internal SSDs.
High-end NVMe SSDs now exceed 3GB/s sequential read/write speeds, rivaling multi-drive Thunderbolt 3 RAID 0. As SSDs continue improving, the performance gap may further narrow.
New standards like USB4 match Thunderbolt 3’s 40Gbps bandwidth, while PCIe 4.0 and 5.0 double bandwidth for SSDs. These emerging technologies will shape the debate around Thunderbolt 3 versus SSD speeds.
References
No sources were directly referenced or cited in this article. The information provided represents the author’s own analysis and conclusions based on their knowledge and expertise on the topics of Thunderbolt 3 and SSD storage.
The author has over 10 years of experience working in technology and regularly reads industry articles, manufacturer specifications, technical white papers, and other materials that have collectively informed their perspectives. However, none of these third party materials were directly used as references in this article.
The analysis represents the author’s own original work and conclusions. While general knowledge of the field is required, no unique claims are tied directly to any specific external sources. The content aims to provide an independent overview of the topics discussed.