Ahead of its Investors Day event scheduled for Thursday, September 13th, Western Digital has announced that it is now sampling a thinnest ever 2.5-inch HDD featuring hybrid technology. At just 5mm thick, the new WD hybrid HDD is perfect for today's thin notebook PCs and should be a viable alternative SSDs in cheaper SKUs.

Earlier this year, Western Digital started to ship its 7mm thick HDDs aimed at thin-profile notebooks and with the introduction of the new 5mm hybrid HDD, it is quite clear that Western Digital is focused at this part of the market and likes of Asus and Acer are apparently companies that will certainly use these drives in its upcoming products in order to create slimmer and more mobile notebook solutions.

Unfortunately, Western Digital did not share many details regarding its upcoming 2.5-inch 5mm thick hybrid HDD other than we will see a capacity of up to 500GB. The new WD 5mm hybrid drive utilizes almost 50 percent less volume compared to current 9.5mm HDDs at one tenth the cost of similar capacity SSD, according to Western Digital.

Western Digital also shed some light on  its Hybrid Technology that pairs MLC NAND flash storage for fast SSD-like data throughput and instant-on responsiveness with magnetic disks for efficient, high-capacity storage, but failed to share any specific details on how much NAND does the new drive actually use or what kind of performance we could expect from this new hybrid 5mm HDD.

Of course, Western Digital will most likely share more details during Investors Day and we will surely keep an eye out for this interesting drive.