Mass Relays are more effective because there are two of them which are tuned into each other. They use the Eezo from both, which each has magnitudes more than a ship does, to generate a tunnel of mass-free space in space-time. Since there is no mass, the ship can travel at theoretically infinite speeds resulting in the instantaneous transportation. A ship with a regular FTL drive can't generate that mass free tunnel, but just an area with less mass, so can't go as fast.
Which is what perplexed me, since doesn't a mass-free corridor and a ship with zero mass basically amount to the same thing? Or is it that the eezo core is less efficient and thus the ships do have at least some mass whilst travelling which massively decreases the speeds to which they are capable of travelling... which seems in keeping with how even the Reapers souped-up FTL is still far slower than a Relay?
Most likely the Primary Mass Relays have more Eezo, thus can generate more Mass Effect thus reach further. Also, the Primary Mass Relays can only connect to one other Priomary Mass Relay while Secondary Mass Relays can connect to any other Secondary Mass Relay within range so that limited connection may also be a factor.
I knew that the Secondary Relays were limited in range, it's just a shame we never got to see a system with numerous Relays in it (aside from Omega) so we could see if there was any difference between the two. I'd imagine that the Primary ones are a lot larger if they have a bigger eezo core that can reach between star clusters.
As for the Citadel, it is a lot more massive than the regular Mass Relays thus is evidently exponentially more powerful and thus a longer reach.
Yeah, since it has enough power to reach Dark Space and activate the Crucible and send the RGB beam between all the Relays, it definitely has a lot of power. That was probably the only thing about the ending that I could believe, since the Citadel has to have the largest power source in the galaxy.
Where does it say the Alpha Relay can reach anywhere in the galaxy? I thought the threat was once the Reapers reached it, they would jump to the Relays it was connected to, and the ones those are connected to, etc until they were all over the galaxy.
I think that Kenson mentioned during the scene heading to the facility, that Alpha has special control switches they discovered that could allow it to reach anywhere in the galaxy, not just the nearest Relay, must like how the Omega-4 has special functions that lock out anyone without an IFF.
Although, could be as simple as the Reapers somehow giving Alpha more eezo to work with and thus more welly.
The Mass Relay in Dark Space most likely only connected to the Citadel, being like the Primary Mass Relays, thus they had to use conventional FTL like we see them do in order to reach the Alpha Relay, which was the closest Mass Relay.
Which is what I thought, but since the Reapers built the Relays, shouldn't they be able to reprogram them, assuming that it doesn't take too much time and that they have the materials necessary in Dark Space to actually accomplish that task?
Course, if the Relays operate by accelerating and decelerating ships between them, then it would follow that the Citadel's massive hidden relay needs an equally powerful "catchers mit" on the other side. Might also be why you can't use the Primary or Secondary Relays to link to each other, as you'd massively overshoot or undershoot your intended targets?