Intel DX58SO “Smackover” Motherboard

Slots and Extra Power

Smackover has two PCI Express 2.0 x16 and one PCI Express 2.0 x4 slots, which can be used to increase the number of video monitors you have installed or to improve gaming performance using CrossFire or SLI modes. Even though the x4 slot is shorter than the x16 slot, you can install a regular x16 card on it, but of course you will be limited to x4 performance. Since the x4 slot is next to the first x16 slot, you can only install single-slot cards on it. So you can have up to three video cards installed on this motherboard.

Figure 4: Slots.

This motherboard requires extra power to feed the PCI Express slots and two options are available: a standard 4-pin peripheral power connector (Figure 5) or a SATA power connector (Figure 6). This is the first time we’ve seen a motherboard allowing a SATA power connector to be used to provide extra power to the PCI Express slots. Using both at the same time won’t hurt, but only one of the two is required.

The motherboard manual, however, is confusing as to when these connectors should be used. It says “Use of the 1 x 4 auxiliary PCI Express graphics power connector (Figure 30, C) or the SATA-style auxiliary power connector (Figure 30, B) is required with ATX12V power supplies when using PCI Express graphics cards that can consume up to 75 W.” This is confusing because it was clearly written by an engineer. The mention to the 75 W PCI Express limit is really confusing to the average user because he (or she) could assume that the manual is talking about the total consumption of the video card. For example, a GeForce GTX 260 video card consumes 182 W and if you follow exactly what is written on the manual, you would assume that the extra power connector should not be installed when you have a GeForce GTX 260. The manual refers to the amount of power pulled specifically from the PCI Express slot (the rest of the power is pulled from the auxiliary power cable that comes from the power supply and is installed on the video card). The manual should have a table listing which video cards require extra power. This constructive criticism is valid to all motherboard manufacturers, as we always have trouble understanding when extra power connectors should be installed.

We asked Intel to clarify this and their reply was “Whenever using a high performance video card it is a good idea to install one of the connectors, just to be sure that the card is able to get all the power it needs, even when auxiliary power is connected directly to the card.,” which obviously stated what we already knew and didn’t answer our question.

Since connecting the auxiliary power connector won’t hurt, we recommend you to always connect one of them. In fact a safer and clearer instruction would be simply saying to the user to always connect one of the auxiliary power connectors.

Figure 5: Four-pin peripheral power connector (extra power for video cards).

Figure 6: SATA power connector (extra power for video cards).