I had AM1 setup which was working as NAS for about 8 months ( later I decided I don't need it ). Something like this:
- ASUS AM1 ITX board
- Athlon 5150 ( 4 real cores, no performance issues )
- 8GB RAM - board supports 2 slots and 8GB is enough for about any configuration
- RAID controller - IBM M1015 which cost me ~$30 , no RAID5 support ( requires additional module )
- 2x1TB SAS RAID1 + 4x2TB WD Purple SATA RAID10
- 64GB Crucial SSD for OS connected to motherboard's SATA port
- Bitfenix Prodigy ITX case
Right now you can get 4-6TB drives in quite reasonable prices and in RAID1 it will work at about 100MB/s. It's still faster than RAID5 on 3 drives and doesn't need expensive RAID controller to have good performance. RAID5 requires good processor so only controller will cost about $300. RAID10 is cheaper from the controller side but you need 4 drives or more and it will give additional performance which you don't need in NAS.
In this case maybe really better idea would be NAS from brands like QNAP.
- ASUS AM1 ITX board
- Athlon 5150 ( 4 real cores, no performance issues )
- 8GB RAM - board supports 2 slots and 8GB is enough for about any configuration
- RAID controller - IBM M1015 which cost me ~$30 , no RAID5 support ( requires additional module )
- 2x1TB SAS RAID1 + 4x2TB WD Purple SATA RAID10
- 64GB Crucial SSD for OS connected to motherboard's SATA port
- Bitfenix Prodigy ITX case
Right now you can get 4-6TB drives in quite reasonable prices and in RAID1 it will work at about 100MB/s. It's still faster than RAID5 on 3 drives and doesn't need expensive RAID controller to have good performance. RAID5 requires good processor so only controller will cost about $300. RAID10 is cheaper from the controller side but you need 4 drives or more and it will give additional performance which you don't need in NAS.
In this case maybe really better idea would be NAS from brands like QNAP.