I ran some frame by frame tests of the mana usage and I was sort of surprised at what I found.

So the way the mana costs are paid for CoB is you pay an initial casting cost a few frames after casting the spell, followed by channel tick cost 2 frames later (always.) And the casting cost was 221, not 220 (always unless you used a SOJ, see below.) After these initial costs, you begin to pay the channel cost in fixed intervals.

The channel tick cost is 33. How often it ticks is based on attack speed. At 1 APS, you pay the channel cost every 30 frames, so twice per second, at 1.49 APS, you pay it every 20 frames, so 3 times per second, at 1.99 APS, you pay it every 15 frames, so 4 times per second.

1 APS, 66 channel cost per second, (2 ticks) 1.49 APS, 99 channel cost per second, (3 ticks) 1.99 APS, 132 channel cost per second, (4 ticks) So when you are forced to recast COB, you don't pay the casting cost, then a second later start paying the channel cost, you are hit with 221+33 = 254 (ouch.) Even releasing the skill as fast as possible, I still paid the first channel tick cost. So accidentally casting CoB is really expensive (Force Move is your friend here.)

Even worse, I found the reduction from SOJ was not as good as you would think it was. A SOJ reduced the casting cost and the tick cost by the same amount. But this amount was not what is listed on the ring.

A -9 SOJ reduced the initial cost by 2 and each tick cost by 2. So at 1 APS, it ticks 2 times per second, so you saved 4 mana per second (you would pay 62 instead of 66.) And the initial cost was 219 instead of 221. At 2 APS, you pay the tick cost 4 times per second, so you get -8 per second (almost the full -9.) I don't know anyone who runs CoB at 2 APS, though.

Similiarly a -5 SOJ reduced the cost by 1 and the tick cost by 1. These numbers are rounded though.

The real numbers went like this (ran over 10 tests)

-4 - reduction of 1 per tick -5 - reduction of 1.2 per tick -6 - reduction of 1.4 per tick -7 - reduction of 1.7 per tick -8 - reduction of 1.9 per tick -9 - reduction of 2.2 per tick -10 - reduction of 2.4 per tick

Works exactly as advertised

Initial cost = 287

Cost per tick = 43

Works exactly as advertised

Initial cost = 188

Cost per tick = 28

So the way the mana costs are paid for CoB is you pay an initial casting cost a few frames after casting the spell, followed by channel tick cost 2 frames later (always.) And the casting cost was 221, not 220 (always unless you used a SOJ, see below.) After these initial costs, you begin to pay the channel cost in fixed intervals.

The channel tick cost is 33. How often it ticks is based on attack speed. At 1 APS, you pay the channel cost every 30 frames, so twice per second, at 1.49 APS, you pay it every 20 frames, so 3 times per second, at 1.99 APS, you pay it every 15 frames, so 4 times per second.

**APS Costs**:Even worse, I found the reduction from SOJ was not as good as you would think it was. A SOJ reduced the casting cost and the tick cost by the same amount. But this amount was not what is listed on the ring.

A -9 SOJ reduced the initial cost by 2 and each tick cost by 2. So at 1 APS, it ticks 2 times per second, so you saved 4 mana per second (you would pay 62 instead of 66.) And the initial cost was 219 instead of 221. At 2 APS, you pay the tick cost 4 times per second, so you get -8 per second (almost the full -9.) I don't know anyone who runs CoB at 2 APS, though.

Similiarly a -5 SOJ reduced the cost by 1 and the tick cost by 1. These numbers are rounded though.

The real numbers went like this (ran over 10 tests)

**SOJ Reduction per tick****So it appears as though you need at least 2 APS to get the full reduction you think you are getting with a SOJ**(and you are still getting hosed on the initial casting cost reduction.)**Pierce the Veil**Works exactly as advertised

Initial cost = 287

Cost per tick = 43

**Blood Ritual**Works exactly as advertised

Initial cost = 188

Cost per tick = 28

Edited by GunnersDream#1109 on 8/3/2013 6:29 PM PDT