This post has been modified heavily due to an error in the research of bandwidth speeds.
If there’s one performance feature of Windows Vista that is actually tangible to the end-user, it’s ReadyBoost. ReadyBoost allows users to increase their system memory without the need to add conventional RAM sticks, instead, users can use removable USB flash drives to act as a temporary (or permanent) memory source.
Currently, system memory is divided into two sources. One source resides is the physical memory (RAM sticks), and the other is the pagefile. Of course the more physical memory you had the better, it can greatly improve performance and reduce effects of ‘disk thrashing’. ‘Disk thrashing’ is the result of physical memory, forcing Windows to store temporary data on the hard drive. The hard drive has no where near the speed of RAM, but offers much more storage capacity at a cheaper cost.
ReadyBoost tackles the memory problem by offering a balanced solution between speed and price. Users can plug in cheap and readily available USB flash drives externally to quickly expand their system memory capacity. Any data stored on the device is also encrypted, offering security on the data stored if the device happens to be forcibly removed. ReadyBoost devices can also be ‘hot unplugged’, removed without prior system notification. It is smart enough not to store any system critical data that might cause unexpected system failures if removed.
Conceptually, ReadyBoost is not only limited to USB flash drives. Brandon LeBlanc reports Jim Allchin had a concept of using the ReadyBoost technology across the network, allowing computers to utilize memory from other (presumably idle) computers on the same network. This demonstrates the capability and potential for ReadyBoost.
But the big question is, how much of a performance difference can it make?
SATA150 currently offers a maximum bandwidth capacity of 1.5Gb/s, and SATA’s second revision SATAII offers a capacity of 3.0Gb/s. When compared to the USB2′s maximum bandwidth of 480Mb/s, SATAII has a clear advantage. If you compare actual write speeds as well, you would find USB flash drives would also lose out to SATAII-based hard drives. So how could ReadyBoost possibly provide any performance boosts? Well there’s one important difference between hard drives and USB flash memory when it comes to sequential access. Whilst hard drives may be great for reading and writing gigabyte-sized files, once you start randomly seeking smaller pieces of non-sequential data across the entire platter, the seek time can greatly influence the read performance. Therefore, if you place a smaller cache on a more responsive device like USB flash memory, and use that cache optimally, there would be a small performance gain.
Not only is ReadyBoost is going to be a great opportunity for consumers, but also hardware manufacturers. With already flash memory at record-low prices thanks to Apple’s iPod-nano, expect even cheaper and faster memory devices in the near future with manufacturers aiming to tap into this unexploited market of expandable external memory.