для энвена 2.1сек, если исходить из трешхолда в 30%
За что купил, за то и продаю. Инфа отсюда:
http://www.icy-veins.com/wow/assassination-rogue-pve-dps-rotation-cooldowns-abilities5.2. Envenom and Energy Pooling
Envenom Icon Envenom is your hardest hitting ability. It also gives you a temporary buff that increases your chance to apply your Poison by 30% for 1 second plus an additional second per Combo Point used.
The buff that Envenom Icon Envenom gives you acts like a DoT, in the sense that when you refresh it, whatever duration was left on the buff (up to a limit of 30% of the original duration) is added to the new one. In the case of a 5-Combo Point Envenom,
it means that if you refresh the buff when it has 1.8 second or less remaining, you will not lose any uptime. So, you simply need to always delay Envenom so that you cast it when the previous buff has dropped or has less than 1.8 second left. Doing so has two beneficial consequences.
You get a higher uptime on your Envenom Icon Envenom buff.
While you wait for your previous buff of Envenom Icon Envenom to drop or have less than 1.8 second left, your Energy will pool, and you will be able to perform more casts of Mutilate Icon Mutilate and Dispatch Icon Dispatch after re-applying your Envenom Icon Envenom buff. This will results in more poison applications and thus more damage.
Note that the Envenom Icon Envenom buff is applied on you before Envenom deals its damage, therefore Envenom will always benefit from its own buff, even if it is parried or dodged.
Refreshing the Envenom Icon Envenom buff before it has 1.8 second left is not always a DPS loss. Capping Energy is a much higher DPS loss than clipping Envenom, so if your Energy is about to cap, you should cast Envenom even if the previous Envenom buff is still active. This happens mostly when you benefit from haste buffs such as Bloodlust Icon Bloodlust, Heroism Icon Heroism, or Time Warp Icon Time Warp, trinket procs or set bonuses.
Pooling Energy is also useful in other situations than Envenom Icon Envenom management, for example when you expect a damage increase (trinket procs, cooldowns, encounter-specific buff, etc.). The idea is that pooling Energy is not a magical DPS gain by itself. It allows you to slightly adjust the timing of your abilities so that you fit more attacks during periods of increased damage (provided you can properly identify when such periods are going to come).