What's the maximum size Windows 7 allows for ReadyBoost?

According to this comment for this post at Windows 7 News, someone is using 8 GB for Readyboost on 1 ExpressCard and 4 GB on 1 SHDC card at the same time.

"MS lists the 8-device, 256-GB-total ReadyBoost limits here:
http://windows.microsoft.com/en-US/windows7/products/features/readyboost"

"I don't know about ""somewhere"" but the Wikipedia ReadyBoost article supports that:

Windows Vista x86 is limited to using
3.5GB (Vista x64 can support up to 16GB); this restriction has been
removed in Windows 7.

and

The initial release of ReadyBoost for
Windows Vista supports one device.
Windows 7 supports multiple flash
drives for ReadyBoost.

However, I can't find anything on the Microsoft site, which isn't encouraging."

Official information from Microsoft can be found on the Windows 7 Product Website with additional information available on TechNet. I'm sure some searching might reveal even more information from Microsoft, but for a start this should be sufficient.

"To know: 'waiting' ram is RAM that is not Free but can be Free inmediatly.

Windows will say Free RAM is zero (at least on my 2BiG), but has more than 333MiB of wainting RAM, that also with ReadyBoost working.

Final conclusion on 32Bit:

better use ReadyBoost with as fast USB sticks as possible on as much USB ports as able to improve speeds
and a 4GiB pagefile allocated on a dedicated HDD as fast as possible, or at least on a dedicated FAT32 partition, never as a file in system partition.

Final conclusion on 64Bit (with a lot of GiB of RAM):

Use a RamDrive for PageFile
If your HDD is fast do not use ReadyBoost

That is what i can say based on my own 'tets'."