distance to servers is on thing, the quality of your modem (especially if your on some sort of DSL) and router is an other. your wifi signal quality is important too. I'm in europe and i usually get pings below 20ms, but i'm one fiber optics.
Steam itself doesn't have a ping. Are you thinking of specific servers for a specific game?
Well, Cablecom is supposed to send me a new modem, dunno how this could help if Speedtest already shows a 25Mbps speed with 30ms ping or so...
throughput has nothing to do with it in this case. its all about ping, jitter and packetloss, try do a pingtest.net
Test it on ethernet.
Sometimes there are interference with wifi.
Anyone else in the house? Maybe someone is torrenting?
Cable modem can differ in speed depending on neighborhood load. For example, evening (busy hours) will definitely be slower.
Distance to server definitely makes a huge difference.
there seems to be no other factor apart from distance to server.
option click the icon in the menu bar.Stick to nearby servers, since upgrading to a really good connection my ping maxes out at 9 on most games because I play on UK based servers. Once I start using mainland Europe or US servers it jumps up considerably.
Wireless interference.
Poor wifi reception. It's easy to check in Windows what speed your wifi connection is (just highlight the connection icon) but I'm not sure how you do that in OSX.
Bad connection.
Interference from phone lines (if so contact your ISP).
both your ping and jitter are high so its on your side things aren't working properly.
this is my results, the furthest away i can get from my router while not going outside.
Image
notice how your ping is almost twice that of mine, but more importantly your jitter is all over the place, basically jitter is variation in ping, and is a good indication of an unstable connection.
try connecting your mac directly to your modem and do the test again.
You are probably trying to access servers too far from you. For me:
US East coast servers can be as low as 20ms
US West coast > 100ms
EUrope: > 200MS