Today we shall review the microATX motherboard P55M-GD45. Like ASRock P55M Pro, it's a very inexpensive board, but not ultrabudget. Modern microATX solutions for Socket 1156 are mostly mid-end boards which trade some expansion slots for compact size. What concerns peculiarities of this model from MSI, we can only mention the power supply system. But let's not put the cart before the horse.
Design
For some reason manufacturers consider it possible to keep obsolete solutions in microATX motherboards, such as connectors for COM or LPT ports on the rear panel. Perhaps, it happens because no one expects assemblage convenience and easy accessibility of all slots and connectors from products of this format. This way or another, the P55M-GD45 PCB is crowded with various components, and engineers had to look for compromise measures to install them all. However, this layout is not very convenient. We can mention the following drawbacks: a graphics card in the first PCIEx16 slot crosses latches on the DIMM slots, the IDE connector is installed at the edge of the board, where is may be too far from the upper CD/DVD drive in the standard tower case (and the usual IDE place is occupied by the much less used FDD).
Everything else is fine: the low-profile heatsink on the chipset allows to install any graphics cards, and SATA ports are installed on their sides, grouped by two at the edge of the board, so they won't interfere with long expansion cards either. Lots of users won't like the set of expansion slots on the P55M-GD45: 2 x PCI Express x16, 1 x PCI Express x1, and only one PCI. Unfortunately for such people, this configuration is the most typical one for microATX models for Socket 1156, just like the cut-down second PCIEx16 slot: it's based on the chipset and operates at the x4 speed of the first version of the standard, so it makes no sense to setup CrossFire here. (No SLI license either.) By the way, as this slot has fewer physical contacts, its farther end has a big nasty backlash.
The P55M-GD45 has a formally simple CPU voltage regulator (the same 4+1 phases as in the budget competitors), but the switching voltage regulator from MSI is traditionally based on DrMOS. However, Renesas R2J20602 chips have been replaced with Fairchild XS FDMF6704V (probably cheaper), but all advantages of the integrated circuits DrMOS over the usual design with MOSFETs still hold true, including compact size, simplified PCB layout, and improved energy efficiency and higher switching frequencies. Considering that the board uses only polymeric capacitors made in Japan, the P55M-GD45 has one of the best power circuits, at least among microATX models.
However, the engineers also simplified the on-board cooling system to cut manufacturing costs. We consistently criticize unreasonably bulky coolers, which are used as decorations rather as cooling components -- the good example here is top motherboards with the P55 chipset (dissipates less than 5 W!) like Gigabyte P55-UD6. Moreover, high temperature contributes to heat release. But don't forget that certain onboard components (for example, MOSFETs in the PWM voltage regulator) heat the board and components nearby (for example, filtering capacitors in the same circuits). This is not good and may result in shorter service life of the latter.
In this case we would have preferred to have a serious heatsink on DrMOS chips, as the existing heatsink (as well as other elements in the CPU voltage regulator) of the P55M-GD45 grow very hot. However, we have no gripes about the chipset heatsink -- it's small, perfectly fits the infrastructure, and remains barely warm at work. Interestingly, both heatsinks are mounted with normal metal screws, so they can be easily removed to replace thermal grease, and then installed back. We are happy to see this technology find its way to low/mid-end motherboards.
