I require a very high performance and very stable hard disk array. I have sketched up a quick cost benefit analysis but I still have some gaps to know which is the right decision for my needs. I will be using an Adaptec 4800SAS as the drive controller.
TYPE CPGB RAID10 RAID5 TOTAL $
73 GB 15k SAS $2.26/GB 73 GB 219GB $660
73 GB 10k SAS $1.78/GB 73 GB 219GB $550
146 GB 15k SAS $1.77/GB 292 GB 438GB $1036
146 GB 10k SAS $1.18/GB 292 GB 438GB $692
As you can see it would seem like 146GB @10k @ RAID10 would be my best bet for the money but it depends on the difference between what I would gain from 15K @ RAID5. Also I dont consider SSD because I'm not so sure it is ready for enterprise level reliability but it is in the same price range. My general uses are occasional games but mainly compiling computer code and 3d artwork rendering etc.
How many drives are you using in your array? For the 73GB drives, you show RAID 10 having 73GB, for the 146GB drives you show 292GB???
Of course 10K rpm is cheaper than 15K. Is the difference worth it? No way to know without knowing the workload, what % of time doing IO (or waiting). How much is the time worth to you. Rendering is probably very processor intensive. Compiling code - a lot of time writing code, how much time does a compile take?
RAID 10 with 10K drives will be FAST. 15K a little faster. But, you knew that. RAID 5 is cheaper per GB but not quite as fast, esp for writes.