As a motherboard designed for an entertainment PC, the AOpen i915GMm-HFS cleverly comes in a more manageable micro-ATX form factor. The board itself is based on Intel's 915 series of chipsets, which is the basis for current Pentium M processors. While the Pentium M and Core Duo have the same socket pin-out (479 pins), they are incompatible with each other. Thus, the i915GMm-HFS will only work with the current generation Pentium Ms, but that's really the beauty of it. The i915GMm-HFS actually uses the 915GM chipset, which has the Intel GMA 900 integrated graphics as well, thus it can truly be called an all-in-one solution for anyone looking for a HTPC motherboard.
For video purposes, the most important function of the GMA 900 is the two Serial Digital Video Out (SDVO) ports that are available to it. Through the IGP's SDVO interface, the mini i915GMm-HFS is able to deliver two major features. The first of which is a simple DVI transmitter, which uses a Chrontel 7307 IC to get the job done and the second, a Chrontel 7021 HDTV encoder with a full set of component output. The Chrontel 7021 can perform VGA to HDTV conversions up to a resolution of 1600x1200 and support HD video from 480p to 1080p. To top off its media functionality, the motherboard comes with Intel's Azalia HD Audio component. The Realtek ALC880 CODEC provides 8-channel analog audio through the rear panel. However, we're sure that HTPC users would be more interested to connect directly to their external decoder or audio system. Well you're in luck as well. While the board may not look like is has S/PDIF connection, AOpen provides some converters with the board to enable this functionality.
With all the focus on audio and visual processing, the i915GMm-HFS is still at heart a PC motherboard and AOpen has surprisingly not skimped on its features. While it may be a micro-ATX motherboard, it holds just as many features as a high-end ATX board. It is also highly compatible with older and newer technologies. The board supports both DDR and DDR2 memory types and enhances the storage limitations of the older ICH6-M by giving it SATA II support through a Silicon Image controller (SiI3132). Besides these and the audio/video functions, the board also comes complete with two full speed PCI Express based Gigabit Ethernet controllers (Marvell 88E8053) and an Agere FW3226 2-port FireWire 400 controller.
The following overclocking options are available on the i915GMm-HFS:
- FSB Settings: 100MHz to 400MHz
- RAM Frequency: 333MHz / 400MHz / 533MHz
- CPU Voltage Settings: 0.700V to 1.484V (Banias core) / 0.700V to 1.356V (Dothan core) (in 0.016V steps)
- Memory Voltage Settings: 2.55V to 3.11V (in 0.08V steps)
- Multiplier Selection: Yes (unlocked CPUs only)
The i915GMm-HFS is a highly specialized motherboard and not really meant for overclocking. The maximum Vcore values are actually the defaults of the Pentium M core, thus there is actually no room at all for boosting voltage. Memory clocks are also locked depending on the type of RAM used. However, we did take it for a spin just to see how scalable it is just in case you crazy enthusiasts feel the need to tweak up your HTPC. As expected, the board didn't hold up too well in the rigors of overclocking and the maximum FSB attainable was 160MHz (just 24MHz higher than the 133MHz default) before our SATA drives began failing.
Now the i915GMm-HFS is a surprisingly packed motherboard and while we do not have any problems with its layout, there were some issues that cropped up during our testing. Firstly, one would notice during installation that the board uses a proprietary CPU cooler and retention system. This means that you can only use the cooler provided in the bundle and not any commercial third party variants. Initial versions of the board shipped with a sub-par cooler that wasn't powerful enough, but AOpen has reportedly replaced it with a beefier version. In any case, our board with the low profile cooler was able to handle a Pentium M 750 with ease and even managed to get some overclocking in without undue problems.
The board also lacks legacy port support, with a bracket provided for PS/2 keyboard connection, but no PS/2 mouse at all. Users would be well advised to switch to USB-based devices if you are to use the i915GMm-HFS.
During our tests, we noticed that the board had some issues with selecting the correct FSB:RAM ratio with DDR2 memory at 400MHz FSB. This problem seemed only to surface with this particular setup and posed no problem with DDR2-533 timings or other DDR frequencies.