Hello, On 03/09/2010 03:50 AM, H. Peter Anvin wrote: > Well, apparently Western Digital are looking at it for USB drives due to > XP compatibility requirements -- those presumably are ATA internally and > use a USB-ATA bridge. This should work right now as long as the bridge chip doesn't screw up, which we can't do much about anyway. USB is used as SCSI transport and SCSI layer has been working fine with devices with differing sector sizes for quite some time. > On the flipside, though, there really is very little net benefit to 4K > as opposed to 512 byte logical sectors: the additional protocol overhead > is relatively minimal, and as long as writes are aligned full blocks, > there shouldn't be any additional overhead on either the OS or the drive > side. On the plus side, you get full compatibility with the existing > software stack. The equation really seems rather simple. Yeap, for addressing, whether 9 bit is shifted or 12 doesn't really matter. That's only 8 times difference which may be breached in probably under three years. If the current 48 bit addressing limit is reached, we would be far better off introducing 64 or 128 bit addressing. That was the reason why I thought that I would never see an ATA disk w/ 4KiB logical sector and got pretty surprised that it was being considered for XP compatibility where 3 year offset could be pretty meaningful. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
