Western Digital WD Black hard drive
Unlike the two other drives tested in this review, the WD Black uses a SATA 2.0 (3Gbps) interface, not a SATA 3.0 (6Gbps) connection. Manufacturers don't make laptop hard drives with a SATA 3.0 interface because the drive's performance can't even fully use a SATA 2.0 interface.
After I installed it into my MacBook Pro, the drive booted up in 20 seconds. Restart took just 21 seconds. While that's not SSD or hybrid drive load time, it's not that far behind; the speed can be attributed to the generous amount of DRAM on board. As the drive fills up over time, I would expect those bootups to slow down significantly.
Opening a 300KB, 372-page Word document took 10 seconds, then an additional 38 seconds to load all the pages.
The second time I opened the document, the RAM cache had obviously kicked in. The Word document opened in 2 seconds, and all 372 pages took only 25 seconds to load. The third time I opened it, Word again loaded in 2 seconds and the entire document loaded in 7 seconds, beating the SSD and hybrid drive alike. I had not expected that.
Opening a 10MB PowerPoint slide took just 2 seconds, the same time as the hybrid drive and the SSD.
Using the Blackmagic Disk Speed Test, the WD Black showed a sequential read/write performance of 122.2 MB/sec. and 119.6MB/sec., respectively. Random (as in Random Access Memory, or RAM) performance is where the drive fell flat: the disk had a random write performance of 67.6 MB/sec and a random read performance of 34MB/sec.
Random performance is particularly important as the drive begins to fill with data and the read/write head must move across the spinning disk to locate the information you want. That requires more and more time as more data fills the drive.
Seagate's Momentus XT Solid State Hybrid Drive
There are industry analysts who believe the hybrid drive's time has come and gone. If you blinked, you missed it.
I respectfully disagree.
Hybrid drives can be a bridge between hard drives and SSDs. They offer SSD performance on critical operations such as boot up and application load times, and provide vastly higher capacities for the money than an SSD.
Fang Zhang, an analyst with IHS iSuppli, says most consumers purchasing a $700 PC or laptop aren't going to spend hundreds of dollars on an SSD. Hybrid drives, on the other hand, can be had for as little as 14 cents a gigabyte. For example, a 500GB Seagate Momentus XT can be purchased on Amazon for $69.99. The owner of that $700 laptop would be a lot more willing to spend one-tenth the price for a significant storage-performance upgrade, Zhang contends.