DIY project power issue question NIC power problem in a do-it-yourself setup
DIY project power issue question NIC power problem in a do-it-yourself setup
Hello, the project involves building a home server box from an old laptop. I took apart the machine and noticed it has a mini PCIe slot—though I don’t know its exact generation—I’m assuming it could handle around 2.5Gbps. My plan is to connect a PCIe NIC like the Edimax EN-9225TX-E, but I’m unsure about the power requirements. Do you know if a PCIe port can supply enough voltage and current for such a device? Have anyone attempted something similar before? * Laptop motherboard - 15SB-GT board * Pcie network card - Edimax EN-9225TX-E
A typical estimate is 3 to 6 watts per port card, which should cover a single port NIC. ServTheHome reviewed a mGig NIC and noted it drawing more than 6 watts when using two ports together: https://www.servethehome.com/syba-dual-2...er-review/
The miniPCI standard only accommodates 1.5V and 3.3V voltages, while a standard PCIe slot requires 3.3V and 12V. It's likely a network card would draw the 12V line, making it incompatible unless you provide an alternative source.
These adapters usually need extra power connected, which should work.
Thanks for the information. I’m avoiding extra power supplies in my DIY project right now. I have two choices: connect via USB to Ethernet 2.5 or 5 gigabit adapter, or use a mini PCIe to a 2.5 gigabit network card from Syba. The latter link I found on their site is https://www.sybausa.com/index.php?route=...ct_id=1082. It looks like this option is the only one they offer. Other manufacturers don’t seem to provide something similar.
Do you have a second device supporting 2.5 Gbps Ethernet or a switch with compatible ports? I wouldn't purchase a 2.5 Gbps Ethernet card anymore as it's becoming outdated. It would be more practical to invest in a few SFP+ 10G network cards plus a DAC cable if you require speeds above 1 Gbps. Regarding the specific card, the details are listed on the page: https://www.edimax.com/edimax/merchandis...-9225tx-e/. The datasheet is available here: https://www.edimax.com/edimax/mw/cufiles...nglish.pdf. According to the table, it consumes about 3.678 watts, though I doubt that level of power is needed for short cables and if you turn off energy-saving modes. That unit might only run at 3.3V, but you'd need to verify directly. I'm checking the edimax website and note that the 12V pins aren't utilized; on the other side, the second and third pins are 12V, suggesting a strict 3.3V configuration. You can review the pinout here: https://pinouts.ru/Slots/pci_express_pinout.shtml
I have an unmanaged switch at home for a 5x2.5 port setup (Edimax GS-1005BE) and a few desktops equipped with 10G NICs (Asus XG-C100C, which were available at a discount). I appreciate your concern; upgrading to a 10G LAN would make more sense, but it would require a new switch and a server enclosure with sufficient PCIe lanes to avoid bottlenecks. I’m sticking with the 2.5Gb approach since it’s sufficient for my needs. Your suggestion made me reconsider checking the card connectors from the photo. I’ll look at the images to see if pins are on the board, or I’ll order one to inspect physically. Since online purchases in our country offer a 14-day return policy, I’m confident this won’t be an issue. When I get back with my findings, I’ll share them here for future reference.
I acquired the Edimax EN-9225TX-E 2.5Gigabit NIC on a PCI-E X1 port. Following @mariushm's advice, I verified the pinout on the rear side of the card and discovered it operates at 3.3V. I also located the PCI Express mini card electromechanical specs document here: https://fit-iot.s3.amazonaws.com/downloa...rev1.2.pdf. Refer to section 3.4.3 for power ratings; the maximum normal current is 1.1A. Using the formula Power (P) = Voltage × Current, the mini PCIe port delivers approximately 3.63W. The only missing piece was BIOS configuration—since the slot was previously used for a HP Wi-Fi card, it might be restricted to whitelisted devices. I ordered the MPCI to PCI-X1 riser and will update once received.