Monday, April 16, 2012

Drive Specs: Hard-Drives -- and Introducing Solid State Drives

When you buy PCs or hard drives, one of the overlooked specs is the speed of data read/writes.  Most often, we see specs on the size of the hard drive (for instance, 500 GBs of space).  However, with increasingly larger file sizes from digital cameras, and high-definition videos, the speed of data access is becoming increasingly important.  

Hard drives come in a range of rotational speed.  The most common speed is 5400-rpm, but 7200-rpm is a popular choice to improve performance.  You'll see a corresponding improvement in transfer speeds if you copy a lot of data -- say HD videos from a full 8 GB memory card -- to your hard drive, so pay attention to these specs.  

If this is an important factor -- you may want to look into Solid State Drives.  These drives have no moving parts, so data transfer speeds are very quick.  Some estimate that the speed is 30 - 100x faster than hard drives!

Speeding Up 

With the very fast paced lifestyle these days, most businesses are time-bound and cannot afford a slowing down in their transactions. This makes speed of HDDs a crucial point in technological purchases. The typical access time for a Flash based SSD is about 35 - 100 micro-seconds, whereas that of a rotating disk is around 5,000 - 10,000 micro-seconds. That makes a Flash-based SSD approximately 100 times faster than a rotating disk. 

This however raises another point - what's the benefit of a high-speed SSD when the entire system cannot support it? The evolution of CPUs in terms of performance has far surpassed the development of the data storage system. The HDD is actually limiting the potential of a computer system when they are not able to keep up with the performance of the other components, particularly the CPU. If an HDD is replaced by a high-speed SSD, the performance would significantly improve.

Read more on SSDs here:

On Flash Drives and SD Cards

Thumb drives and SD cards are slower than HDDs.  They use less battery than an SSD because they don't have as many chips that operate in parallel or a sophisticated controller with RAM caching. And they'll definitely use much less battery than an HDD. But they're also a lot slower for the same reasons.