Hope I don't offend the Dev Team or anyone else with this post.
During testing of performance, It was very interesting to find that assigning more cache devices to Win7's ReadyBoost yielded higher values as opposed to having less devices amounting to the same size.
i.e.
1 usb flash disk using 2GB cache in ready boost gave me a direct access measurement 20MB/sec via eBoostr Control panel "Check Speed".
2 usb flash disks using 1GB each (2GB total) cache in ready boost gave me a direct access measurement 25MB/sec via eBoostr Control panel "Check Speed".
3 usb flash disks using 683MB each (approx .2GB total) cache in ready boost gave me a direct access measurement 30MB/sec via eBoostr Control panel "Check Speed".
I realize that the random read speeds of the disks are different, but an interesting note is that the above figures applies no matter which disk I used for scenario 1. and combinations for scenario 2.