yea, because its already cold, and you now introduced heat into your chiller. thus the raising of temps. What you now have is increased capacity though. Let your chiller run for a while before you turn it on. Let it pull down as cold as it will go, then pump for about 30 seconds so all the warm liquid in the lines is displaced with cold. Then let the chiller run until it brings it down to that same temp. Turn pump on, and then computer. It will give you a head start on heating up the water. for a few minutes you will have colder liquid then the chiller can produce while the computer is on...
unless your video cards are not sub zero prepped... then don't let your chiller get that cold. you should get it warmer. Let me know when your ready to play with the big dawg & get it colder