Which storage fits best to ObjectDB?

Hi,

we are just about to put together a new server for our applications using ObjectDB (v 2.6). We have a dilemma about the storage holding the ObjectDB files:
if to invest in a mirrored RAID of SSDs which is clearly the ultimate solution but it quite pricey, or to choose a RAID5/6 of 7200 RPM HDDs.

The reason we are asking the question in this forum is that we would need to know how ObjectDB is reading/writing the files. The tests are showing that the HW RAID5/6 of HDDs deliver comparable (but still lower) speeds of data transfer to a single SSD, however only when tested on large media files, so in fact it means sequential reads/writes. If it is tested on small files the speed is getting considerably worse.

Our DB files range from 700MB to 5GB.

So the question which arises: does ObjectDB read/write the DB files by large chunks and then it parses it within the RAM (so it would mean reading/writing of large data fewer times) or the DB file is only a big container in which every DB request is searching for the correct place to read/write right on the disk (it would mean then r/w of small data more often, so the seek-time is the most crucial and not the transfer-rate) ?

The ObjectDB database file is a container of pages, and only pages that ObjectDB needs are loaded from disk to RAM (when needed). Therefore, unless the database file is small and cached completely (by ObjectDB or OS cache), SSD is expected to be faster, since it significantly reduces the seek time.

That was my guess too, but I wanted to confirm it.

Thanks!