top of page

Summary Performance Comparison - HDD, SSHD, SSD

 

The measurements were taken by Calypso on the SSSI RTP/CTS test platform pursuant to SNIA Solid State Storage Performance Test Specification version 1.1.

How does one use the PTS to evaluate and compare SSD performance? First, data should be collected by using the SNIA PTS on an SSSI Reference Test Platform (RTP) to get standardized and normalized results. The user should then select the key measurements from each of the three metrics (IO/s, TP and LAT) to compare the overall performance.

There are commonly accepted block size and RW mixes that are used to evaluate SSD performance. While users may have an interest in other specific access patterns, industry convention uses device level 'corner case' (or boundary) testing to evaluate SSD performance.

While IO/s, TP and LAT have long been used for the testing of HDDs, the SNIA PTS methodology has added solid state storage specific processes to accommodate the uniqueness of SSD performance. Specifically, the PTS defines a standardized pre-conditioning and steady state determination to ensure the SSD is properly prepared as well as SSD specific tests that address SSD specific performance behaviors.

Form factor

Without any moving parts, SSD products are the thinnest of the available storage options. They’re especially good for thin and light PCs and complex, industrial designs. For standard notebooks, SSDs are available in 5mm and 7mm heights. By comparison, HDDs are available in standard 7mm and 9.5mm designs. SSHDs debuted at 9mm, will be available at 7mm soon, and 5mm designs have been announced for shipment in 2013.

 

Capacity

HDDs are the workhorses when it comes to sheer capacity and how much data can be stored. SSHD technology also offers maximum capacity points at affordable price points while SSDs are only affordable at lower capacities. High-capacity SSDs are extremely expensive.

 

Speed

SSDs provide peak performance for booting and high read/write performance to supporting computing that requires enhanced multitasking capabilities. On the other hand, an SSHD can provide near–SSD performance for booting, launching, and loading data. HDDs usually provide ample performance for the majority of PC platforms available today.

 

Price

At a system level, low-capacity SSDs can be affordable in the 32GB to 64GB range. But high-capacity SSDs are very expensive, especially when measured by cost per gigabyte. HDDs provide the lowest cost per gigabyte. SSHDs provide a cost per gigabyte that’s just slightly higher than HDDs.

 

Battery Life

In general, storage will not impact battery life in a laptop computer by more than about 10%. Processor power and LCD really run down the battery. However, SSD is the most power-efficient, and SSHD is a close second because it can spin down more frequently than an HDD.

 

Reliability

Failure rates on SSD, HDD and SSHD technologies have very similar ratings. SSHD has benefits because it uses both the SSD and HDD portions more efficiently than if they were separate.

 

Durability

SSDs are viewed as more durable simply because of their solid state design. Without moving parts, they can withstand higher extremes of shock, drop and temperature.

 

Summary

Thinking through all these criteria may make upgrading laptop storage seem like a tough decision. But perhaps it all comes down to cost-effectiveness: how can you get maximum capacity that’s nearly as fast as solid state but fits your budget better?

Take a closer look at solid state hybrid drives. They probably provide the best combination of performance characteristics to meet your needs.

bottom of page