Leaving aside any other issues caused by my outdated and overworked SLI graphics cards, I have at least tracked down the cause of something that made the game unplayable. Where I used to enjoy frame rates of around 80-100fps, a few months ago this dropped to below 30 with an extremely jittery image, with the only solution seeming to be switching to Force Single GPU mode. Today after a driver update I decided to try some more troubleshooting and came across a breakthrough. While in orbit, the image of my ship in flight seemed to be perfectly fine, however as soon as I entered my inventory, the frame rate dropped again. I moved over to the collection to inspect individual armor pieces, where framerate returned to normal. After narrowing things down, I found that the sparrow I had equipped, Pale Steed, was the source of the frame rate drops. Switching it out for another sparrow instantly resolved the issue in the inventory screen. Loading into the H.E.L.M and the Tower still resulted in framerate drops. My hypothesis is that either the equipment of other players loaded into memory, or another environmental effect using the same shaders, particle or lighting effects may be causing the slowdown here. I've inspected several other Sparrows to see if the issue occurs elsewhere, and compiled the following list: Kindled Wanderer, Quadracycle, Gouging Light, Long Haul Wagon, Dawning Cheer & Vanishing Point. Of special note here are Quadracycle, which appears to play a sparking animation then returns to normal fps after about 10 seconds, and Dawning Cheer, which returns to normal fps after about 3 seconds. I've also found slow down on the Wayfinder's Compass seasonal artifact, the Synaptic Spear seasonal artifact, the ship Wings of the Firebird, and the following ghost shells; Hearthfire Shell, Long Haul Shell, Awakened Shell, Hardlink Shell & Void Shell, as well as every finisher, and every emote that uses a hologram. I also get slow down on so many Transmat effects that it's easier to list the ones that don't cause slowdown; Taken Arrival, Arc Effects & Solar Effects. Here's a DxDiag: https://pastebin.com/Pjy98dh2