After having been announced in January of 2007, version 1.0 of the DTX specification was released in February. Initiated by AMD, DTX is meant to become a new open industry standard for small computer systems. The goal is to create a form factor that is smaller than microATX, but bigger than mini-ITX.

Size wise, the difference between computer cases housing a microATX motherboard and standard ATX form factors tend to be marginal. However, compared to DTX, a full-size ATX system can almost be described as hulking. According to the DTX specification, a DTX motherboard measures 244 mm by 203 mm. However, the boards retain the spacing of the mounting points from the ATX standard, making them downward compatible with older cases.

Motherboards adhering to the mini-DTX form factor are a little bit smaller still, measuring 170 mm by 203 mm. They, too, are downward compatible with the ATX standard.

DTX cheaper than ATX?

DTX motherboards should be less expensive than ATX and even microATX motherboards, since motherboard manufacturers should be able to reduce costs due to the boards’ smaller size. In effect, the same blank that would usually be used to make two standard ATX boards would allow them to make four DTX motherboards or six mini-DTX boards instead. Besides, DTX and mini-DTX boards only require four layers. The downside to the smaller size of DTX systems is their lower upgradability, as the boards only sport two expansion slots, namely 1x PCI and 1x PCIe. Also, due to their slim design, DTX cases will only be able to accommodate so-called low-profile cards. Luckily, most add-in cards such as sound cards, network adapters or storage controllers are already available in low-profile variants to ensure maximum flexibility and enabling their use in rack-mounted servers only two units high (2U-systems).

Comparing the ATX and DTX form factor reveals another similarity, as both use the same power connector. Like motherboards conforming to the ATX 2.2 specification, DTX boards also sport a 24-pin power plug with an identical pin configuration. The same holds true for the 2x2 processor power connector, which is a mandatory feature for DTX just as it is for ATX and BTX. This isn’t really that surprising, considering that DTX as a concept is characterized by the idea of being as flexible as possible, which also means fitting right in with the existing ATX world.