For Edinburgh, their miserable run of consecutive RaboDirect PRO12 defeats in 2012 extended to 12 as Michael Bradley's men continue to flounder in the league despite reaching the Heineken Cup quarter-finals.
Edinburgh drew first blood and after five minutes Sep Visser finished off a fine, flowing Gunners' move to cross for his first RaboDirect PRO12 try of the season.
Phil Godman missed the conversion and Ulster's South African out-half Pienaar had the chance to reduce the arrears to two just two minutes later but he was wayward from the tee.
But the Ravenhill faithful didn't have to wait long for something to cheer about and on nine minutes, D'Arcy's fine break opened up the Edinburgh defence and he found Pienaar, who in turn fed Marshall to score.
Pienaar was on target with the conversion and Ulster, with the wind in their sails, struck again on 15 minutes with flying winger Terblanche going over in the corner.
Ulster led 14-5 after Pienaar's fine conversion and while Edinburgh tried to hit back through Tim Visser, the hosts furthered their advantage before the break, this time the impressive D'Arcy finished off a patient move.
Pienaar, who was dictating proceedings for Ulster, added the extras but Edinburgh grabbed a lifeline just on the half-time whistle when Godman notched his second penalty of the night after some ill-discipline from Ulster.
And Edinburgh seized that initiative immediately after the break and forced another penalty on 41 minutes, but after a lengthy pause in play due to a serious-looking injury to flanker Mike McComish, Ulster's superiority at the scrum forced a penalty try and secured the bonus point - the imperious Pienaar again slotting the conversion.
And the South African demonstrated his versatility by switching to scrum-half with Humphreys entering the fray for the last 27 minutes, before setting up try number five for Cochrane.
Pienaar took a quick tap just five metres out from the Edinburgh try line and spread the play wide for Cochrane to cruise over for his second Ulster score.
In the closing stages, Ulster, with the bonus point win already secured, began enjoying themselves and in a eye-catching move, orchestrated by Paddy Wallace, Cochrane was denied a second by some desperate Edinburgh defending.
Tim Visser grabbed his 12th try of the season to seal some consolation for Edinburgh but Humphreys' late breakaway try ensured the Ulster fans went home with smiles on their faces.
Victory leaves Brian McLaughlin's men hot on the heels of Glasgow, who now hold fourth place ahead of Ulster by just a point following their victory over Ospreys.
|Ulster Rugby Score Card|
|Edinburgh Rugby Score Card|