Solid State Hybrid Drives (SSHDs) combine traditional hard disk drives (HDDs) with solid state drives (SSDs) to offer a balance of affordability, capacity and performance. But how do they compare to pure SSD storage in real world use? Let’s take a look at the key differences.
What is an SSHD?
A solid state hybrid drive contains both a traditional hard disk drive and a small solid state drive. The SSD component acts as a cache to store frequently accessed data, while less accessed data sits on the larger HDD. This aims to give you SSD-like performance for your most used files and applications, while enabling larger capacities than a pure SSD at a lower cost per gigabyte.
SSHD vs SSD Speed
SSDs are significantly faster than HDDs due to their lack of moving parts and direct electrical connections. This allows SSDs to have near instant access times and very fast data transfer speeds. A SATA III SSD can achieve sequential read/write speeds of around 500-550MB/s and random access speeds of up to 100,000 IOPS.
HDDs rely on moving magnetic platters and read/write heads, so they have much slower access times in the 10-15ms range. Their maximum sequential speeds top out around 100-150MB/s for today’s fastest models. That’s 3-5x slower than SSDs.
SSHDs slot in closer to HDDs for overall performance. The SSD cache can dramatically improve access times and random I/O performance when data is in the cache. But if data needs to be retrieved from the HDD portion, performance reverts to HDD levels. Sequential speeds are also capped by the HDD’s ~150MB/s limit.
Benchmark comparisons
Here are some benchmarks comparing SSD, HDD and SSHD drives in popular tasks:
| Drive Type | Sequential Read | Random Read IOPS | Game Load Times |
|---|---|---|---|
| SATA III SSD | 500MB/s | 100K | 25 seconds |
| SSHD | 150MB/s | 12K | 45 seconds |
| HDD 7200rpm | 150MB/s | 1.5K | 60 seconds |
This shows SSDs have a commanding lead in all areas. SSHDs can get within the ballpark of SSDs for random IOPS thanks to their SSD caching, but sequential speeds and real world game load times still lag behind full SSDs.
SSHD Cache Sizes
The size of the SSD portion in an SSHD has a major impact on performance. Entry-level SSHDs have as little as 8GB of flash storage, while high performance models may have 32GB or more. The larger the solid state cache, the more data can be stored on the faster SSD portion instead of the hard drive.
8GB provides a basic speed boost for frequently used files, but can be saturated quickly. 32GB or higher allows your operating system, apps, games and frequently accessed files to reside in the cache for best speeds. Look for at least 16-32GB of SSD cache if you want your SSHD to approach SSD-like speeds in daily work.
Advantages of SSDs vs SSHDs
Pure SSDs retain significant performance advantages over SSHD technology:
- Faster overall: SSDs are 3-5x faster than HDDs and SSHDs for sequential and random access.
- Lower access times: SSDs have near instant 0.1ms access times compared to 10-15ms for HDDs and SSHDs.
- No caching management: SSD performance is consistent, while SSHDs rely on caching algorithms to optimize for frequently used data.
- Reliability: No moving parts makes SSDs more reliable and shock-resistant.
- Noise and heat: SSDs run silently and cooler than HDDs and SSHDs.
For the highest all-around performance with no caveats, SSD is the clear choice. The benefits are especially noticeable when loading games, apps, movies or large files where the full SSD speed is maintained.
Advantages of SSHDs vs SSDs
SSHDs do retain some advantages of their own over pure SSD solutions:
- Cost per gigabyte: SSHDs are significantly cheaper than similarly sized SSDs.
- Capacity: SSHDs are available in much larger capacities from 500GB to 2TB without breaking the bank.
- Basic SSD benefits: The SSD cache still improves access times and everyday speeds for active data vs HDDs.
The lower price and higher capacities of SSHDs can make them appealing for cost-focused upgraders or gamers needing mass storage. The SSD caching enables noticeable improvements over HDD alone, even if not matching true SSD performance.
When to Choose an SSHD
SSHDs can be a good choice in these scenarios:
- Gaming rigs needing high capacity for a game library on a budget.
- Upgrading the main drive in an older system without breaking the bank.
- Adding a fast but affordable secondary drive for data storage and backups.
The hybrid design lets you get more speed than an HDD alone, while the large capacities and lower cost are advantages over SSDs. Just don’t expect true high-end SSD performance levels from an SSHD, even with plenty of cache memory.
When to Choose an SSD
SSDs are the better choice if you want maximum speed and the full solid state advantage. Especially for drives handling your operating system, apps or games, SSDs are easily worth the price premium.
SSDs are highly recommended for these uses:
- Boot drive for your OS and main apps.
- Primary drive for gaming PCs.
- Running professional apps that need fast storage.
- Any application where maximum performance is critical.
The combination of consistency, reliability and 3-5x the speed of HDDs makes SSD the top choice for intensive computing workloads. For more casual needs SSHDs can get you improved everyday speed at a lower cost.
SSHD vs SSD: Which is Better for You?
So is an SSHD or SSD the better choice? Here are a few key considerations:
- If you want maximum speeds for critical apps and games, choose SSD.
- If you need high capacities on a budget, consider an SSHD.
- For a boot drive, always go SSD over SSHD when possible.
- Use SSDs for primary storage and SSHDs for secondary data drives.
- Higher SSD cache capacities help narrow the SSHD vs SSD performance gap.
In the end, SSD is the clear performance winner, while SSHD offers a compromise between speed and affordability. Just be aware of the caching limitations of SSHDs that prevent full SSD-level speeds. For critical tasks demanding peak performance, SSD remains the gold standard.
Conclusion
SSHD technology combines HDD capacity with SSD caching to offer a balance of affordability and performance. But while SSHDs can come close to SSD speeds for cached data, overall they lag well behind true SSDs.
SSDs are 3-5x faster across the board and come without the caching drawbacks inherent to SSHDs. For top performance in gaming and professional workloads, SSD is the superior choice despite higher prices per gigabyte.
SSHDs do provide a worthwhile speed boost over HDDs thanks to SSD caching, which makes them a viable budget-friendly solution. Just be aware of their limitations compared to true SSDs. When your computing demands pure speed, SSD remains the gold standard in storage.