Not sure what OS you are using, but Win 7 has built in RAM disk I "heard" that works pretty good.
However, I use DataRam RamDisk and it works "almost" perfectly.
When you create the ramdisk image, you can set the parameters you are mentioning here within the setup box spanning 3 little tabs.
DataRam RamDisk lets you easily format the drive, mount it in WMI, save the image somewhere, save a "shadow" copy upon shutting down windows, or force a save at any time if you like. Then, on restart, even though all data was deleted, you can set the time that the ramdisk loads to help circumvent this issue. However, it might be a good idea to NOT load eBoostr automatically on startup as the disk won't be there for it to see until your timer ticks down.
Note: could we be experiencing a bug here? I use 3 seperate sources for my eBoostr caches. I am using a RAMDisk, a USB Flash drive, and a little micro SD card. All mainly just for testing purposes really.
When I installed eBoostr, built my cache, and commenced to play all was well, for a time. Not sure at what point it started, but eBoostr stopped loading ANY of the disks. I have to manually reformat each of the drives everytime I restart windows or crash for whatever reason.
One way I "think" this can be fixed is if the cache disks are unloaded and disk cacheing stopped before shut down. I say this because if I do manually do just that from within eBoostr control panel, upon reboot, it loads each disk successfully.
Since this just recently started happening, I'm gonna reinstall Windows and start fresh with the same setup and see if I can't catch it when it starts.