Last month 65.5 percent of computers worldwide used Windows XP, approximately 16.5 percent used Windows Vista, and 9 percent used Windows 7. Looking ahead to 2011, Windows XP is likely to give up some market share, especially with a number of corporate networks upgrading to Windows 7. Still, Windows XP is likely to defy logic and cling to substantial marketshare next year.

And that brings about a thorny and underpublicized problem. Windows Vista, Windows 7, along with OS X Tiger, Leopard, Snow Leopard and versions of the Linux kernel all support hard drives with a 4KB sectors. Windows XP does not.

In 2011 all hard drive makers have agreed to abide by an agreement ironed out by the International Disk Drive Equipment and Materials Association (Idema), which will dispose of the older 512 byte block format and switch all drives to 4KB blocks.

Does that mean the end of hard drives for Windows XP, currently the world's top operating system? Not quite. The Idema plan is gracious enough to call for the 4 KB (4096 byte segment) to be aligned with the past 512 byte segment. So Windows XP users can still buy new drives and use them.

That said, there's a major catch performance-wise. In some cases what took a single operation on older drives will take two operations due to an emulation layer needed to allow Windows XP to treat the new drive format like the old one. Overall, experts estimate users will take a 10 percent performance hit.

Windows XP is typically lauded for its performance and certainly was a marvel of operating system design by the time it hit SP3. However, the hard drive switch should shift the performance balance in Windows 7's favor. Using the larger block size, Windows 7 will feature eight times less wasted space and twice as many bits-per-block devoted to error correction. Overall this shift will improve the speed and reliability of Windows 7, while reducing its power footprint. Meanwhile Windows XP will hold steady in reliability, but will perform worse both in speed and power consumption.

Source: DailyTech