These are fairly classic symptoms but they may not present obviously enough early on.
I had a power supply issue with my old Corsair CX430 (430 Watt).
The build had two old 95W Xeon CPUs, 2 USB devices and a PCI-E powered Nvidia Quadro or at one point a GT710. This shouldn't have overwhelmed the PS but this power supply is known to be weak by many users.
Symptom 1. Graphics Issues
This would only present it self after coming back with the........
This is the Intel Atom 330 motherboard with integrated Realtek Gigabit NIC (Intel Desktop Board D945GCLF2 Motherboard W/ Atom 330 1.6 GHz Dual Core Processor - Mini-ITX)
I cannot achieve more than 15 MB/s, even doing a local transfer through eth0 to it's own IP.
100% 95MB 15.9MB/s 00:06
So this is not a cabling, switch or hardware issue, it seems like a driver or chipset limitation problem.
Here is my........