I was watching this video and he mentioned shredders not using pentatonics often.
Yet tbh, that’s my go to shred scale, Likely from my time spent in it and my affinity for marty friedman style down up down picking.
What would you guys class as a true shred scale? As in an easy and good sounding scale to play fast?
That’s a strange thing to say.
Honestly? The chromatic scale.
Certainly Eric Johnson, Joe Bonamassa, and Zakk Wylde shred pentatonic scales all the time.
I think what they must mean is that the classic shred scale shapes are 3-note-per-string patterns. All the scale stuff on Intense Rock is 3 NPS, loads of Joe Satriani’s legato ideas, Malmsteen, Vai, Petrucci. Many people find two note per string picking is surprisingly awkward by comparison.
Though that’s not really a scale and can sound bad unless you know how to use it.
I guess the question I’m asking is in most shred solos, what is the main scale used?
I know yngwie malmsteen is known for the harmonic minor. But that’s about all I know.
That basic shred sound in most 80’s metal, what is it?
There’s nothing out there that this doesn’t apply to.
This is twos and threes and fours.
This is the same stuff but without the processing.
If you want the easiest fast scale its the major scale.
Ask Paul Gilbert about 3 NPS and Pentatonic scales 
A ----------6-7-10–
E 5-8-10------------
Then repeat from D-7 and so on.
Includes a little stretching but it is in fact what the OP was asking for.
Note that the A-6 above is the blue note. Strictly pentatonic notes in that 3-nps pattern would be as below, which includes the 3rd degree twice (on separate strings):
A ----------5-7-10–
E 5-8-10------------
Or you can include a shift to get a 3nps pattern of straight minor pentatonic with the root at the beginning and the end:
A ----------7-10-12–
E 5-8-10------------
I think one of Frank Gambale’s books or videos also breaks down sweep/economy patterns for the pentatonic scale.
Edit: And looking back at Gilbert’s Intense Rock II, he does blazing fast pentatonic licks incorporating strategic hammerons and pulloffs in two-note-per-string shapes. Gilbert himself has said over the years that he doesn’t do as much strict alternate picking as people think he does. It was actually kind of funny listening to Intense Rock II again, because in my head I strongly associate some of the fast pentatonic licks with Zakk Wylde.
As far as pentatonics in a “shred” context, I always come back to Rusty Cooley’s “Seven Deadly Sins” lesson from Chops From Hell, way back at the dawn of the internet:
http://www.chopsfromhell.com/columns/guest_cooley_7ds1.html
ll the way at the bottom, “Wrath.” C Major Pentatonic, four notes per string. The stretches are a bit nuts, but holy hell does it sound mind-bending at full tempo.
Pentatonics, Dorian and Mixolydian Modes, Chromatics, Arpeggios - This gives you pretty much everything EvH did (and all his copycats).
Add the Harmonic Minor and Phrygian - Then you get Randy Rhoads and Yngwie,
Gambale, Vai, and Satriani use some of the Melodic Minor modes, Lydian Dominant and things like that.
Honestly, there is no 1 scale that you play it and it sounds like 80’s metal. Lead playing in any genre is more about playing chord tones with passing tones over changes.
Complete with Realplayer video clips! 
[Clicks link and opens a new tab]
[Starts watching video] “Hmmm, ok those stretches are pretty wild but at least he’s going slow through this and doesn’t seem to speed it up toooeedla;sfj;lkas;skfdg;lksfdga…”
[Calmly closes browser tab and goes to quietly sit for a while]
Honestly, I was worried people might not even HAVE Realplayer anymore - on my laptop, I couldn’t open them, myself!
Yeah, that was pretty much my first reaction too, back in like 1999 or 2000 when I first saw this. Cooley is a whole different breed, and I’m pretty sure his fretting hand isn’t human.
Honestly, Chops From Hell was a pretty awesome resource back in the day. Them and… Cloud9 records? Shred9? Something like that… Lots of underground shred musicians, lots of articles and interviews, and LOTS of lessons, with some pretty cutting-edge content for its day. A lot of it was beyond my ability back then but I learned a lot from the site nonetheless.
EDIT - nope, still can’t do the “Wrath” lick stretches cleanly. 