How do you get legit relay bandwidth ballpark figures?

Question

I'm using STEM.

I'm trying to create custom circuits based on relay information but I'm unable to get reliable relay information.

RouterStatusEntryV3.measured which appears to be the heuristic I want is only present in votes, don't know what good that does.

So I am trying to rely on: ServerDescriptor.observed_bandwidth

But I'm starting to think that the figures I get for it are easily manipulated, for example these are all the relays that scored about 30,000,000 for observed_bandwidth:

(u'redjohn', 49539919)
(u'3cce3a91f6a625', 35733555)
(u'ReflexZincIodide', 30074192)
(u'splitDNA', 61044132)
(u'spfTOR1e1', 33526216)
(u'bierchengaming', 41275593)
(u'aurora', 42918130)
(u'redjohn1', 46646602)
(u'darkit', 51785012)
(u'kingara', 39454901)
(u'AviatoChortler', 31605961)
(u'PrivacyRepublic0001', 35796370)
(u'PrivacyRepublic', 37152280)
(u'PrivacyRepublic0002', 32340142)
(u'torfoo', 31626087)
(u'mendes', 38276617)
(u'ivpn', 39880632)
(u'impastato', 33078832)
(u'blurgh', 32762505)
(u'shifidi', 32420401)
(u'BeSeeingYou', 37975858)
(u'chulak', 41998005)
(u'SGGSUK1', 49636671)
(u'dorrisdeebrown', 32150565)
(u'IPredator', 37708096)
(u'quadhead', 34545546)
(u'ReflexZincOleate', 30948496)
(u'SGGSUK4', 31549249)
(u'SECxFreeBSD64', 30841913)
(u'esbek1', 32608555)
(u'TorLand1', 50596734)
(u'becks', 51748076)
(u'orion', 39549063)
(u'destiny', 56923898)
(u'xshells', 34367620)
(u'Lule', 37474592)

As best as I can tell, some of those are lies. According to TorStatus, the following are lies: splitDNA, aurora, [stopped checking].

I don't know what can I trust? I want to be able to form circuits through very well traveled nodes. But it seems like the consensus contains untrusted information? What should I do?

Answer 1

Tor automatically builds the fastest circuits possible for you by attempting to see how much bandwidth is available for each node. It doesn't rely on the client supplied Bandwidth value but actually tries to test the node by building various circuits and timing the requests. Sometimes those tests are inconclusive, never get run, or just come up with bad information so you can't rely on that specifically.

This talks about how bandwidth is checked and used. https://gitweb.torproject.org/torspec.git/tree/path-spec.txt#n92

It should be noted that the Tor path-spec should be used and not your custom speed-based one if you value anonymity. But I assume you've decided that's not a priority.