I recently received a new custom gaming rig, and sadly soon found out that the latency was very high and unstable. Thus, causing some games to stutter.
I have a GIGABYTE PCI slot card with two antennas. I have yet to test via Cat5 cable to see if it the card's problem or not.
For example in League of Legends, every few seconds my ping rises from a stable 35 ping- 250 and back down again. This happens often. In games like Blacklight Retribution my ping will be about 55 and it would jump to 85 and stutter for half a second and then stabilize again. Like I previously mentioned I will test with a Cat5 cable and see if this resolves my issues.
I currently don't have easy access to a ethernet plugin so I might try and disable the PCI card and buy a USB WiFi Adapter. Any help would be great.
Sounds like you are on the right track. It is very common to get random errors on wireless lots of things can cause interference. Along with the USB adapter buy a USB extension cable it will allow you more option in the placement, most PCI cards suffer from being blocked by the computer case.
If it does not work on the ethernet you sadly will have to complain to the ISP who may not be able to do much if they have oversold the network in your neighborhood.