SB750, and summary
SB750 southbridgeOften the weak link in previous AMD/ATI boards, the southbridge for 790GX has been upgraded to SB750, supporting RAID5, and a new feature that helps overclock Phenom-based CPUs. Used with what AMD terms Advanced Clock Calibration (ACC), Phenom CPUs can be better overclocked by 'retuning their internal parameters for greater performance', according to AMD's engineering team. The proof will lie with the testing, and we've still to receive a crystal-clear reason as to why SB750 mojo helps overclock the CPUs to higher frequencies than by adjusting the parameters in the BIOS.
Note that the SB750 can be paired with existing chipsets to provide the same overclocking boost, so it's not a feature that's solely peculiar to the 790GX, and we've seen it on select 790FX boards.
Summary
AMD's 790GX chipset is a logical extension of the 780G that debuted a few months ago, bringing with it more speed and a greater feature-set. We expect most mainboard partners to ship regular ATX-sized motherboards, housing 2x x16 PCIe 2.0 slots (2x x8 in CrossFireX), and, hopefully, to push the IGP core's speed even higher. MicroATX models will follow shortly, we've been informed.
Indeed, 790GX is what 780G should have been; the headroom has always been there. Our hope is that retail examples arrive at the same cost a vanilla 780G's, at around £50, otherwise the bonus of the IGP is somewhat negated
The best-featured IGP-based chipset has just got better. The question on whether it provides a reasonable gaming experience, when compared to low-end discrete cards, will be answered in our performance look.
