AOpen’s i975Xa-YDG mobo is a fully featured board based on Intel's 975X/ICH7R chipset, supporting Intel’s Core Duo and Core Solo processors, up to 4GB of memory and ATI's CrossFire technology. The board layout is generally very good, with all components located in almost ideal positions. The area around the CPU socket is clear, but because the mobo supports Intel's current 65-nanometre mobile chips, there isn’t a need for an oversized heatsink fan combination.
However, there is room around the CPU socket for something a little more extravagant if you're in to extreme overclocking. AOpen includes a small aluminium fan in the box - the fan spins slowly and the heatsink never gets hot, even when the CPU is heavily overclocked. The north bridge is also actively cooled with an aluminium heatsink and 40mm fan combination. However, this combo doesn't appear to make a great deal of noise, subjectively speaking.
The memory slots are located along the bottom edge of the board. Installing pairs of memory modules in the same colour slots will enable dual channel DDR2 memory. Unlike AOpen's i915GMm-HFS Pentium M motherboard, the i975Xa-YDG only supports DDR2 memory, so you will need to purchase new memory if you haven't already got DDR2 modules.
The board has memory dividers for 533MHz and 667MHz - there is no support for DDR2-800. These are slightly confusing in some respects, as the memory doesn't run at that speed with Core Duo's default quad-pumped 166MHz front side bus. When the DDR2-533 divider is selected, the memory uses a 3:4 memory divider, meaning that the memory is only running at 442MHz DDR. The 667MHz divider uses a 3:5 divider, meaning that the memory is running at 553MHz. At this point, it is worth mentioning that the memory runs at full speed when the CPU's front side bus is increased to 200MHz.
The board only has four internal SATA 300MB/s ports that are all controlled by the ICH7 south bridge; these ports are not capable of handling RAID, because only the ICH7R south bridge has support for RAID. The south bridge also controls a single IDE port, while the ITE ATA133 disk controller controls the other two IDE ports. The ITE controller supports RAID 0, 1 and 0+1 arrays with up to 4 disk drives. Interestingly, AOpen has opted not to cool the south bridge – it is possible that the ICH7 chip doesn't give off as much heat as the ICH7R south bridge, as just about every motherboard maker has passively cooled the ICH7R chip on their LGA775-based 975X motherboard designs.
Below the floppy connector, there is an infrared receiver pin header for the included remote control - the i975Xa-YDG includes a lot of media centre functionality, as well as being reasonably well-featured too. Below that there is a system speaker - it doesn't look like this can be disabled though, as there isn't any sign of a motherboard jumper to turn it off.
In the bottom corner of the board, AOpen has opted to include on-board power and reset buttons. These are starting to appear on more and more motherboards, and we always find them incredibly useful.