Raid and disk configuration - New Dell PowerEdge 2950 Server

Hi All,Looking for some guidance. My new server has 3 x 146GB SAS 15k 3.5" HD which came in pre-configured as RAID 5 and 2x 73GB SAS 15k 3.5" HD as RAID 1. Should I leave it as it is or change it? Now I understand that for the best performance tempdb and log files should be on separate raid1 drives. But this is impossible in my situation…
Rgs,
N_A

that is limited configuration
any way , RAID 5 data , tempdb
Raid 1 log
also , raid 1 will have windows os , sql binaries
if you can , add two extra disks as raid 1 for log only

How big do expect this DB to get? Any idea on how many transactions?
If you expect a high number of writes, you may be better off changing to a RAID 1 with 2 x 146 GB drives for your data files, and leaving the RAID 1 with 2 x 73 GB for Windows, logs and tempdb. RAID 5 would slow down your writes considerably. You could maybe use the left-over 146 GB drive for your page file or whatever else you may have that has no need for redundancy.
Regardless, since these are SAS drives, and you have few of them, your disk queues are gonna be pegged no matter how creative you get.

Well at the moment my db is 20GB and is growing about 0.5 GB every month, 50 users using db everyday for read and write. Transaction log grows by 1GB per month. I am thinking getting extra disk to make 3 Raid 1 disks, but still undecided...

What about getting extra hard drive and making 3 Raid 1 disks?

With a db that big you should consider scrapping sata hd's and going with 15,000rpm scsi drives. You will find that you get to a point where CPU and Memory is not an issue and this is the only thing that will make a huge difference. The hard disk does its work more than twice as fast and sql isn't left waiting...