BarraCuda Hard Drives

Capacity

8 TB
6 TB
4 TB
3 TB
2 TB
1 TB
RPM 5200
RPM 7400 Cashe MB 64 / 256

Seagate’s BarraCuda hard drives are perfect for laptop storage, mobile storage, all-in-one storage and more.

All hard drives in the BarraCuda family come equipped with Multi-Tier Caching Technology (MTC). By optimising data flow with intelligent layers of NAND Flash, DRAM, and media cache technologies — get faster load and applications times and improved read and write performance.

Multi-Tier Caching Technology™

How Layering an Application’s Cache Improves Performance Modern data storage needs go far beyond just computing. From creative professional environments to desktop systems, Seagate provides solutions for almost any application that requires large volumes of storage. As a leader in NAND, hybrid, SMR and conventional magnetic recording technologies, Seagate® applies different levels of caching and media optimization to benefit performance and capacity. Multi-Tier Caching (MTC) Technology brings the highest performance and areal density to a multitude of applications. Each Seagate product is uniquely tailored to meet the performance requirements of a specific use case with the right memory, NAND, and media type and size. This paper explains how MTC Technology works to optimize hard drive performance

MTC Technology: Key Advantages Capacity requirements can vary greatly from business to business. While the fastest performance can be achieved using Dynamic Random Access Memory (DRAM) cache, the data in the DRAM is not persistent through power cycles and DRAM is very expensive compared to other media. NAND flash data survives through power cycles but it is still very expensive compared to a magnetic storage medium. Magnetic storage media cache offers good performance at a very low cost. On the downside, media cache takes away overall disk drive capacity from PMR or SMR main store media. MTC Technology solves this dilemma by using these diverse media components in combination to offer different levels of performance and capacity at varying price points. By carefully tuning firmware with appropriate cache types and sizes, the end user can experience excellent overall system performance. Since the disk drive on-board controller manages the data flow, the operating system and application work seamlessly in executing read/write operations.

Single-Tier vs. Multi-Tier Caching Traditional disk drives use single-tier cache to speed up data flow from the host to the magnetic media main store—also known as permanent storage. In this scheme, shown in Figure 2, DRAM serves many purposes. A small DRAM buffers randomly written data and reorders them before writing to the main store. Reducing the number of seeks during a write improves random write performance significantly. During sequential write operations, such as streaming, DRAM helps to minimize fragmented writes by merging writes to disk. DRAM also serves as a read look-ahead cache, which can help certain random read operations. However, due to the limited size of the DRAM, the benefit of the read look-ahead cache is limited.

MTC technology adds various caching layers to further improve both read and write performances. Depending on Seagate’s implementation, some or all of the caching tiers can be utilized for a specific product. In data shown in Figure 3, NAND flash and Media cache layers are added to provide additional performance boost. In this example, NAND flash is used to store most-often-read data to increase read performance while media cache is used to merge small block writes. Since the NAND flash size is in the order of gigabytes compared to the hundreds of megabytes found on DRAM, cache hit is higher by order of 100 times. For fragmented write operations, media cache boosts performance as DRAM reaches its limit. Media cache can sustain a near-sequential data rate of up to scores of gigabytes to better handle burst workloads. All user data are protected and moved in and out of the main store storage without host intervention, making the MTC Technology completely transparent to the user.