I'm thinking about upgrading the OS / application drive for an HP DL 580 G5 running windows server 2003 64-bit. We currently use 3 75GB 10k rpm SAS drives in RAID 1. The server is mainly used for running a memory and pagefile-hungry application, by about 10-20 people at a time. It has 32GB of ram and 32GB of pagefile, and most of the time the pagefile usage is > 50%. The application in question uses lots of virtual memory even when there is plenty of spare ram available (up to 6GB of ram per session + the same of v. ram, and some users work with multiple sessions). More people are going to be using the server fairly soon, so it's likely that an extra 32GB of ram will be installed to accommodate them.
I have the option of spending ~£2800 per unit to replace the 3 SAS disks with 2 HP SAS SSDs (632502-B21), but I'm not sure whether the expense would be justified by the performance gain in this scenario. Should I splash out on the SSDs, or would it be more sensible to stick with the existing drives?
Obviously this will depend a great deal on how much of a performance gain we get from this particular application (I don't have that information yet), but are there any more general considerations that apply here?