Removable drive filesystem and Readyboost

I just discovered why certain USB thumb drives or SD cards are always rated as "does not meet the performance requirements" by Windows Vista when I want to use Readyboost on those devices - they were formatted as FAT32. When I reformatted say my old 2GB SD card back to FAT, Windows would then allow ReadyBoost to be used on it.

 

Does anybody know more details about the filesystem performance mechanics that can make this such a significant factor? My "default" preference would have been to use FAT32 to achieve smaller file allocation sizes. Well, not that it would really matter when I use the entire drive for a single readyboost cache file….

 

maybe the act of formatting the drive made the difference, not the filesystem type? after all this means the disk is wiped clean (at least from the MFT/FAT perspective only) and the cache file that will be created will be contiguous, not fragmented.

You can try formatting one of your devices as a clean FAT32 drive. It probably won't work, in my experience.

it seems others have mixed experiences...some are saying their devices only qualified for ReadyBoost when they formatted it to FAT32, some even to NTFS! what exactly is Microsoft looking at when allowing a removable disk to be used for ReadyBoost anyway?

There are some speed requirements documented by Microsoft. It does not mention any performance differences between FAT and FAT32. In fact, the Q&A expects a FAT32 filesystem (otherwise it cannot go beyond 2GB) for a large drive.

Another thing I notice with a particular thumb drive model that I have - although the Autoplay dialog box appears with the "speed up my system" readyboost option when I plug it to the USB port, nothing happens clicking on it, and the Properties dialog box does not have the Readyboost tab. This means it cannot even tell me if this device is too slow for Readyboost. Formatting FAT or FAT32 has no difference for this thumb drive. I wonder if there are other hardware requirements to make that tab appear?

 

Another thumb drive I have also met Readyboost performance requirements after I reformatted it with FAT.

well as they say... "YMMV" that's why it's best (though potentially more expensive, due to branding/licensing agreements) to buy a USB flash drive that has the ReadyBoost logo if you really want to use it for ReadyBoost.

then again, with a 2 GB+ machine, is ReadyBoost really beneficial?