It goes without saying that Discipline priests will use one of their
major glyph spots for the Power Word: Shield glyph as the spell is a
cornerstone of our build. And as Flash Heal triggers Grace,
Inspiration, Rapture and Renewed Hope, it's a safe bet for major glyph
spot number 2.
Based on the recommendations at Violaceous Mana, I took the Prayer of
Healing glyph as my third one. However, having read some discussions
over at Matticus's blog and on the PlusHeal.com forum, I wondered if
I'd chosen incorrectly. Some Disc Priests were recommending the Holy
Nova glyph instead, and so with a few hours left before I can escape
work, I thought I'd do some math to see if I should re-glyph.
(Warning: I suck at math. Hard. Core. Which makes theorycrafting probably pretty darn futile on my part.)
HOLY NOVA
Heals: At level 80, Holy Nova heals group members within 10 yards for
713-827. Holy Nova benefits from 30.35% of your spellpower, so with
1700 spellpower (Khæli's current level) and with the Twin Disciplines talent, it'll heal each nearby party member for roughly 1260-1410.
Mana Cost: Holy Nova costs 25% of base mana, which translates into 965 at level 80. With Mental Agility, this is reduced to around 870 mana.
+/-: It's instant cast, and therefore benefits from Twin Disciplines
and Mental Agility. It deals damage (398-462 base damage to all
enemies within ten yards). It does not trigger Inspiration. The ten
yard radius requires party members to be near me to benefit.
Glyphed: Healing is increased by 40%, while damage is decreased by
40%. This increases the heal to around 1047-1215 per group — around
1562-1730 at 1700 spellpower.
PRAYER OF HEALING
Heals: At level 80, Prayer of Healing heals group members within 30
yards for 2091-2209. This spell benefits from 80.68% of spellpower, so
with 1700 spellpower, it'll heal party members for roughly 3462-3580.
Mana Cost: Prayer of Healing costs a hefty 48% of base mana, which at level 80 is 1854.
+/-: 3 second cast time. This spell does trigger Inspiration. The
thirty yard radius allows for more distance between healer and tank
(and encounter).
Glyphed: Heals an additional 20% of original heal over six seconds.
At 1700 spellpower, this would add a HoT of 692-716 to the heal.
Total Amount Healed:
Glyphed Holy Nova: 1562-1730
Glyphed Prayer of Healing: 4154-4296
Heal Per Second (Total Heal Divided by Cast Time — or by 1.5 in the case of Holy Nova):
Glyphed Holy Nova: 1041-1153
Glyphed Prayer of Healing: 1384-1432
Heal Per Mana:
Glyphed Holy Nova: 1.82-1.98
Glyphed Prayer of Healing: 2.24-2.31
For group healing then, Glyphed Prayer of Healing wins on all accounts,
even (and somewhat surprisingly I guess since I've always considered it
to be such a mana-heavy spell) in terms of HPM. That it heals for
more, for less mana per heal, at a larger radius confirms Violaceous
Mana's assessment that PoH is the way to go for the third Disc glyph.
(It's not like I really doubted her in the first place, just for the
record.)