Switching from a traditional hard disk drive (HDD) to a solid state drive (SSD) can provide a noticeable boost to laptop battery life. SSDs are more power efficient than HDDs for several reasons.
Why SSDs Use Less Power Than HDDs
There are a few key differences between HDDs and SSDs that account for the power savings of SSDs:
- No moving parts – SSDs have no moving mechanical components, unlike the spinning platters and moving heads of HDDs. The motion requires considerable energy.
- Lower latency – The lack of moving parts allows SSDs to access data almost instantly. HDDs can take up to 16ms for the platters to spin into place for reading/writing data. This lag requires power.
- Lower power usage – SSDs consume typically 30-80% less power than HDDs during active use. SSDs use 1-3 watts versus 5-7 watts for HDDs.
- Faster spin up – With no need to spin up platters, SSDs can be ready to transfer data almost immediately. HDDs can take several seconds to spin up from idle.
All of these factors allow SSDs to get the job done while consuming less juice from the battery. For laptops running on batteries, this can make a significant difference in run time before needing to be recharged.
Measuring SSD Power Savings
Just how much battery life improvement is possible by switching to an SSD? Here are some examples of tests that have been conducted:
- AnandTech saw a battery life gain of 28 minutes (18%) when using an SSD in an ASUS Eee PC netbook during web browsing.
- StorageReview saw the battery life of a Lenovo T420 laptop improve by 15% with an SSD compared to a HDD.
- NotebookCheck saw about a 10% battery life improvement during DVD playback on an Acer Aspire 4820TG after swapping the HDD for an SSD.
The savings can vary based on the test, the size and power demands of the display, and other factors. But in general, 10-20% longer battery life is typical when switching from a HDD to SSD.
Power Considerations by SSD Type
There are several types of SSDs, and some are more power efficient than others:
- SATA SSDs – The most common type, used in most laptops and desktops. More efficient than HDDs but use more power than some SSD formats.
- M.2 SSDs – A compact SSD form factor. Similar power usage to 2.5″ SATA SSDs in most cases.
- NVMe SSDs – Newer SSD protocol with very high speeds. Can use slightly more power than SATA in some tasks.
- DRAM-less SSDs – Contain no power-hungry DRAM. More efficient but lower performance than SSDs with DRAM cache.
For the lowest power consumption, DRAM-less SSDs are ideal. But they tend to be slower. For a good balance of efficiency and speed, a SATA SSD is recommended for most laptop battery life improvements.
Tips for Maximizing Battery Life
While switching to an SSD can extend battery runtime, there are other ways to gain a little more juice:
- Dim the screen – Less backlighting will consume less power.
- Turn off WiFi/Bluetooth when not needed.
- Close any apps not in use.
- Disable unnecessary background processes.
- Use battery saver power mode.
- Make sure batteries are calibrated periodically.
Combining these tips with an SSD should provide a noticeable boost over HDD-based laptop batteries. Just don’t expect miracles – at best you may see 30-60 minutes of extra time under light usage.
Conclusion
Upgrading to an SSD can offer a tangible improvement in laptop battery runtime compared to traditional hard drives. The power efficiency benefits come from the lack of moving parts, lower latency, faster wakeup, and lower power draw of SSDs. Real-world testing has shown 10-20% better battery life is common after switching to an SSD, with the savings more pronounced under heavy disk access. For those needing to squeeze every minute of untethered computing from their laptop batteries, an SSD upgrade delivers results.
| SSD Type | Power Usage | Performance |
|---|---|---|
| SATA SSD | Low | Good |
| M.2 SATA SSD | Low | Good |
| NVMe SSD | Moderate | Excellent |
| DRAM-less SSD | Very Low | Limited |