X99 CPU connector placement: 4-pin when needed, 8-pin available, 4+4 pin schematic options exist.
X99 CPU connector placement: 4-pin when needed, 8-pin available, 4+4 pin schematic options exist.
Hey everyone, the issue you're describing is pretty interesting. It seems like different technicians got different results based on how they connected the fans and power components. The schematics for X99 boards can clarify this. Plugging only 8 pins usually works best for RGB fans, while using 4 pins might affect performance or compatibility. Connecting 4+4 pins (like PSU to MB and PSU to MB) is often recommended for better stability and power delivery. Understanding these differences helps avoid confusion when setting up builds.
The variation lies in the cable’s capacity to supply power to the processor. High-performance chips might need more current than a single 4-pin connector can deliver without overheating or causing noticeable voltage loss along the cable. The EPS 8-pin connector is the standard for CPUs, while some power supplies allow splitting this connector into two 4-pin sections, enabling support for older boards that only need a 4-pin interface. Certain motherboards include additional 4-pin or 8-pin connectors alongside the main one—using these extra cables is usually not necessary unless you're pursuing extreme overclocking (like liquid nitrogen). The 4-pin connector can provide about 216 watts to the CPU, which is sufficient for processors up to roughly 175 watts (typically quad-core chips). The 8-pin connector offers four pairs delivering around 336 watts, offering more current due to tighter wire packing; thus, it covers CPUs using less than 300 watts comfortably.
It might be due to how the RGB LEDs are connected to the fan controller. The 8-pin setup could interfere with the signal path or power delivery needed for those lights. Regarding the 8-pin EPS on an MB case, it’s likely a compatibility feature for older motherboards, ensuring proper power and data routing. The different pin layout helps avoid conflicts with other components like the CPU.
Uncertain about the situation. It could be the 8-pin cable is damaged with a short circuit, or perhaps you accidentally used a PCI-E 8-pin connector instead of the EPS type, which wouldn’t fit due to mismatched pinouts. The CPU power connectors are quite basic—two horizontal rows of pins, one for 12V and another for ground—so they look like a single thick wire for voltage and a separate wire for ground. On most motherboards, these only supply the VRM, the DC-DC converter that feeds the CPU. The fan headers draw power from the 12V wires located in the 24-pin ATX connector.
I don’t have an 8pin, I have 4+4 pins on the PSU (and no way both of those guys connected GPU connectors as EPS). The 4+4 setup plugged into the 8-pin on MB, but MB didn’t even start when the RGB controller was connected. That’s super odd. My PSU is a GX 650W.