Superfetch
Superfetch technology is an extension of XP’s Prefetch. It watches what the user is doing and switches priority between foreground and background applications on the fly. This allows the OS to make sure that maximum time is given to processes should the system be unattended. It also keeps track of what applications you use, and pre-loads portions of them into memory to increase start up speeds and it does this very effectively. This information that Vista accumulates over time about your application usage enables the OS to learn and to some extent predict exactly what you’ll be doing on a day to day basis.
The goal of Superfetch is to ultimately load data into memory before you actually require it, thus cutting down on wait times. This according to Microsoft should result in a system that is faster and more responsive the more you use it in a work session. Due to multicore CPU’s being increasingly common nowadays, it is incredibly important that it is constantly fed with data otherwise you’ll incur a performance loss.
Low Priority I/O
In Windows XP users had the ability to run processes at different priority levels, with the CPU allocating more time to high priority tasks then the lower ones. In Vista this is now extended towards disk I/O (Input/Output). Now background processes can be written to use low priority I/O, which enables foreground applications to jump the queue and gain first access to the hard drive, with the overall benefit being that you’ve got a more responsive system.
Many of Vista’s own services now use low priority I/O. One of these is the ‘new’ disk defragmenter. I could see the difference right away as I ran this for the first time. Unlike the Diskeeper Lite defragmenter in XP, the Vista version allowed me to comfortably work away without any odd lengthy pauses in my work. If I should require disk access then the Vista Defragger will easily pause, and then resume as normal. It’s just a shame that the Vista defrag utility is so poor feature wise in comparison.
ReadyBoost
With Windows Vista, you really need to have at least 1GB of memory available if your PC is going to run with performance comparable to Windows XP. Unfortunately, for some upgrading memory is either a complicated matter, or a rather expensive one. ReadyBoost works alongside with Superfetch and allows USB flash drives to operate as a large cache, sitting between the system memory and the hard drive, while boosting overall responsiveness.
Using this feature is as simple as plugging in a compatible USB flash drive and selecting ReadyBoost from the Autoplay menu. If Autoplay is disabled on the OS, then you can access the ReadyBoost options from the drive’s properties menu. Vista will then automatically test the device and if it performs its read/write operations within Vista’s recommended performance specifications then it will be used transparently.
ReadyBoost can actually speed up your system because high performance flash memory is capable of much quicker random access performance then a hard drive. Most USB flash drives on the market offer capacities from 256MB up to 4GB. Thanks to the increasing popularity of these devices, they can be a cheap way to speed up system responsiveness instead of buying more memory. The performance benefits are mostly noticeable on systems with ram under 1GB.
ReadyDrive
ReadyDrive allows Windows Vista to use new hybrid hard drives that incorporate internal flash memory. As flash memory has no drive platter to spin up to speed and no head to move into position, the superior random access speeds of flash memory come right into play. These drives should provide faster booting, hibernation and resuming once they arrive. They should also require less power too.
Advanced Performance for Hard Disks
Upon enabling this feature, the hard disk will operate in write-back cached mode, where all the data that gets written to the drive is first stored in the cache, and then later written to disk. Both writes and reads are cached in this case. When this is disabled (default), the hard disk operates in write-through cached mode where all the data that gets written to the drive is immediately written to the disk and also stored in the cache. So writes aren’t cached, but reads are.
However, if you lose power with Advanced Performance enabled the data stored in the cache may never be written and lost for good. Enabling this option on an overclocked PC is also a huge risk. Due to overclocked PC’s being rather unstable until system stability has been achieved, it is a good idea to leave it off.