virtualbox.org

Is there any performance benefit if you run your VM on an SSHD with a 8gb ssd buffer Ex: Seagate ST2000DX001 SSHD

If the Vm vmdk size is more than 70gb would it buffer some sectors on the 8gb of the SSHD?

You would need to ask the drive manufacturer about the criteria it uses to move data to flash. The most obvious implementation is that everything gets moved to NAND flash to begin with, until it's full, then blocks get replaced on an LRU basis (Least Recently Used). Incidentally, this would work at a sector/page level, the nature of the host data wouldn't be relevant (e.g. whether it's part of a file, and if so what kind or size). So if a file is moved around the drive, the cached pages would be invalidated even if the file is not changed - because the drive doesn't understand filesystems, just sector addresses.

From Facebook Segate Support page

We will reply here and you may post our answer on the forum if you wish. The SSD NAND would store the most frequently used data up to 8 gigs in this case. If the data is not on the SSD then it would be paged from the rotating drive. If there is a 70 gig data pool and the data has not been accessed for 6 months then there would not be any performance increase as the data would likely not be located on the 8 gig NAND SSD flash memory. However if the data is being accessed frequently then the performance should be improved if the data resides on the SSD NAND flash.

I'm not sure why you pasted that in. It doesn't seem to add anything to what we already knew from your first post, and it doesn't affect my answer.