IMO
Speed = free base amphetamine/amphetamine sulfate
Rock, ice = Methylamphetamine HCl
Now, theres smokable Methylamphetamine HCl in its powder form, this just means
a) Its been crushed
b) It hasn't gone thru a proper recrystallisation after conversion from freebase to HCl.
Talking pure ice and relatively pure smokey...There is alot more impurities(not cut) in the smokable meth due to the recrystallization process to make proper shards pushes the impurities out and leaves it at the bottom of the dish. The proper shards will grow near perfect after a few rXtilizations...
You can give a whacker(IV user) 2 points .2 of a gram of PURE ACETONE WASHED Ice, they'll love it, rush + hurl for a few minutes and it'll have fuckn legs!
You can give a whacker 2 points of smokable meth, it can give them anything (depends on certain solvents left in it n shit), but some IV users prefer smokey vs ICE due to little impurities carried thru from the reaction (i.e. they love iodomethamphetamine !!

) Them two points might give em a much bigger rush, and longer rush than ice will.
Best rocks i've smoked was recrystallized shit from side of an ounce bag(i dont give a fuck, i dont do it anymore ne way) 4-5 points all up recrystallized in a cup.
Anyway, fuck the shit. Been off it for 4 months now and I was the biggest ice-hero here on AusDD.
Tis not worth it, unless you sell it and dont use it, get sluts + money, what more could ya want?
But yeah, don't use it. Ya just can't think clearly at all..