Dell has shipped several versions on the 530s system.
The following applies to the standard 530s system:
- Upto 8GB of RAM can be used providing the BIOS is version 1.0.12 or later (current version for 530s is 1.0.18). Release notes for version 1.0.12 state a fix for memory configurations >4GB. Remember to read all the guidance before updating BIOS as this is an advanced procedure.
- You can install up to 2GB of memory per slot.
- Dell advises these should be matched pairs - one pair in DIMM 1 and 3 the other in DIMM 2 and 4.
- RAM should be DDR2 SDRAM(667/800-MHz) 240pin variety.
- The manual for the 530s has not been updated to 8GB and still says 4GB is max supported. Also note that if you use the Crucial.com scanner, it will also state only 4GB is supported, which is the "official" spec but not the real story.
I have been running a 530s system with 6GB RAM. I can confirm it is addressed and utilised by 64bit versions of Windows Vista and 7. There is no point having more than 4GB RAM in a 32bit system as 32bit cannot address more than 4GB.
Hope that helps.