- PCI Express® based PC is required with one X16 lane graphics slot available on the motherboard
- 500 Watt or greater power supply with two 75W 6-pin PCI Express® power connectors recommended (600 Watt and four 6-pin connectors for ATI CrossFireX™ technology in dual mode)
- Certified power supplies are recommended. Refer to http://ati.amd.com/certifiedPSU for a list of Certified products
- Minimum 1GB of system memory
- Installation software requires CD-ROM drive
- DVD playback requires DVD drive
- Blu-ray™ playback requires Blu-ray drive
- For an ATI CrossFireX™ system, a second ATI Radeon™ HD 5850 graphics card, an ATI CrossFireX Ready motherboard and one ATI CrossFireX Bridge Interconnect cable per graphics card (included) are required
The system requirements for two HD 5850s in CrossfireX mode is 600W according to ATI’s website. I would strongly recommend at least a 700W PSU to run two HD 5850s as the cards, while taking less power than a HD 4890 still require a lot of power. ATI has a list of recommended PSUs on their website. Unfortunately, their list has not been updated as of yet for the HD 5xxx series but I would suggest using the equivalent HD 4xxx series card, i.e. 4870 to 5870, 4770 to 5770 as a good guide. Each of the cards requires two 6-pin power connectors, meaning that two HD 5850s require four 6-pin power connectors.
The second part of the system requirements is the overall system including the motherboard, memory, CPU. A motherboard with two separated PCI Express x16 slots is required to run in CrossfireX mode. The HD5850s I have to test are both dual-slot solutions requiring the PCI Express x16 slot and an adjacent slot for the cooler. I would strongly recommend a fast CPU such as a Core i7 870 or 920 at the least. as otherwise the games will be CPU limited. Another consideration is the memory. ATI recommends at least 1GB of memory. I would recommend at least 2GB for the two HD 5850s as each card has 1GB of memory on it.