Check out Stormkeep. Their first EP Galdrum and their album Tales of Othertime have beautiful dungeon synth parts.
Genre-wise I would say you find something like this in the Atmospheric and Melodic Black Metal area, but both does not inherently mean that it is dungeon-synthy, sadly.
To throw a few names out there that might fit:
- Stormruler: More towards Melodic BM, but it scratched the Stormkeep itch for me after some time.
- Ungfell: One of my favourite swiss bands, more medieval/folky sounds, worked for me.
- Ateiggär: Similar to Ungfell, yet still different.
- Ophanim: Even more atmospheric.
- Summoning: One of the first bands with this sound, check out Long Lost Where No Pathway Goes.
- Emyn Muil: Very Summoning-inspired.
- Arx Atrata: Also very atmospheric.
I might remember more in the future, if I do, I'll update this comment.
This speed is the Specific Impulse which is a measure of how effective the fuel mass is used. It is equivalent to the effective exhaust velocity, which is basically the mean exhaust velocity as the real exhaust velocity depends on the position in the exhaust. The specific impulse is more often given in seconds like in the Wikipedia page for the thruster and this representation is connected to the speed-based representation by dividing the effective exhaust velocity by the standard gravitational acceleration at sea level. Mass is not present in both of these representations because this way they are the impulse per unit mass of propellant.
Electric thrusters reach very high exhaust velocities, but the fuel mass flow is limited which leads to low thrust. Chemical engines reach high thrust, but their exhaust velocities are quite low in comparison.