Microsoft Windows Vista ReadyBoost and ReadyDrive Primer
This information comes the official Windows Vista help database as well as our own testing:
Windows Vista can use flash memory as a high-speed cache for storing frequently used data.  This is called "ReadyBoost."
The amount of this memory should be between 1X and 3X the size of your system's main memory (RAM).
Therefore a flash disk in the 2GB to 4GB should be the right size for most consumers.
However, you may use a larger flash disk.  If you do use a larger flash disk, Vista will let you allocate
part of the capacity for the ReadyBoost feature, allowing you to use the other as you see fit.
Not all flash disks are fast enough to be ReadyBoost compatible.  Many cheap USB sticks are not fast enough,
and according to Microsoft, some use a mix of fast and slow flash memory, giving you a smaller ReadyBoost
capacity than you want (or maybe not enough to even use).
To use Vista ReadyBoost, the flash disk MUST be connected to a USB port.  This means you can connect directly to the motherboard's internal
USB header with our internal USB SSD from PQI, or you must connect the disk externally.  All of our SSDs can be
attached externally via an IDE to USB adapter.  They only cost about $20.  Although Windows Vista will only USE up to 4GB, you can attach
a 32GB SSD via a USB cable and Vista will use 4GB of that disk, leaving the rest for you to use as you desire.
OUR EXPERIENCE:
We are very excited about the new internal 2GB USB SSD from PQI.  It connects to your motherboard's internal
10-pin USB header.  All PQI SSDs use durable, reliable, industrial-grade NAND flash chips from Samsung.
ReadyBoost is an inexpensive way to speed up your experience WHILE Windows Vista is running.  There is some
debate on weather it will accelerate boot times since ReadyBoost is acting as a hard disk cache, and it wouldn't
seem that anything would be cached when the system is shut down.  In testing of the PQI DOM 2GB SSD sold here, it DID
decrease  boot time.  Before installation, it took the system 32.5 seconds to reach the initial Windows splash screen,
and a total of 37 seconds to reach the desktop.  After installation and a couple quick reboots, no change.  So I left the
system idle, and when I came back into the room Windows was heavily accessing the hard disk even though I had not
opened any programs. It must have taken that idle time to start caching, because when I rebooted, the boot time had
dropped 11.5%.  Time to initial splash screen was 31 seconds.  Time to full desktop totaled 33 seconds-- a 3 second
drop.  Time to recover from sleep mode was nearly instantaneous.  It took longer for my CRT monitor to warm up
and show the picture than for the system to wake up.  Test system: 3.00Ghz P4, 2GB SDRAM, 250GB Maxtor
Maxline Plus II, Sony dual layer DVD recorder, nVidia Geforce 5900 AGP.
With the case panel removed, we simply plugged in the DOM to one of the two USB headers on the motherboard.  Window Vista
immediately recognized it and asked if we wanted to use it to "speed up system performance."  I answered yes, and it allocated
1874MB (1.84GB) of the 2GB module to ReadyBoost.  You can adjust the slider at any time from the minimum allowed
to the max capacity of the module.
We have seen another  benchmark where boot time DID improve when the ReadyBoost drive was formatted
with NTFS (link).  We've also seen a video demonstrating a faster boot time from the initial Windows screen to the actual
desktop. There is also a huge blog on the ReadyBoost topic here.
As we mentioned before, Vista only looks at USB devices for ReadyBoost usage.  I plugged in a SATA Flash Disk and Vista
did not recognize it as a ReadyBoost device, even though it plenty fast.  I attached a PQI IDE SSD internally, and it was not recognized for
ReadyBoost, but I attached the same disk externally via a USB adapter, and it was recognized for ReadyBoost.  You can use a slider to
select how much of the disk to use for ReadyBoost, leaving the rest for other purposes.
Windows Vista Installation on a solid state disk
We recently decided to do a clean installation of Windows Vista RC2 on a PQI 32GB IDE solid state disk to compare it with
an identical in installation on a Maxtor 250GB 7200 RPM hard disk.  After about 4 reboots, Windows Vista displays a consistent
boot time (Apparently it performs some optimizations during the first few boots).  We found that Windows Vista will boot
faster using a solid state disk.  Using the Maxtor hard drive, our test system posted these results:
Time to initial Windows Splash Screen:  43 seconds.  Total time to Desktop added 2 more seconds for a total of 45 seconds.
SSD performance:
Time to initial Windows Splash Screen:  36 seconds.  Total time to Desktop: 40 seconds.  5 second advantage = 11%
"ReadyDrive" is Microsoft's term for hybrid drives.  A Hybrid hard drive is a hard disk that has a large amount of
embedded flash memory that can be used to store frequently used operating system and program information.
This can speed boot times like ReadyBoost.  When data is found in the cache, the hard disk platters to not have
to spin up.  This has an additional effect of improving battery life on a laptop computer.
Hybrid drives have ONLY 128MB or 256MB of flash memory on them.  Why not just buy a pure SSD drive that is
at least 2GB?  And if you buy one that is larger than 4GB, use the rest as you desire.  The MINIMUM amount of
flash memory that Windows will use for ReadyBoost is 256MB, so we find it odd that that is the MAX provided on
any hybrid drive. Seagate hybrids will have 256MB.  The first Samsung hybrids will have 128MB, with 256 to follow.
Hybrid drives require Windows Vista to operate
Make your own Hybrid for ANY OS!
Simply purchase a Solid State Disk of any capacity that you want.  Put your operating system on it, or whatever programs
you deem appropriate, and pick whatever hard disk you already have or wish to buy!
Our new Solid State Disk Forum is a good resource to check every now and then.