After reading a few articles and tests regarding the new IC Diamond 7 Carat Thermal Compound
), I had to try it out myself. I've been using AS5 for a long time, and until now, I guess I haven't really appreciated how easy AS5 is to work with. IC7 consistency, compared to the rather oily AS5, is more like working with model putty. It reminds me of the ShinEtsu I used years ago. The manufacturer’s instructions states that you should apply a thin coat of IC7 on the IHS, but that is easier said than done. It tends to peel off leaving holes in the coat as you apply it. The place I bought it from suggests you should heat up the syringe before using it, but problem is, as soon as you place it on the IHS it cools down again. So I also had to heat up the CPU/IHS (using a hot halogen lamp), and I'm guessing the IHS temp was around 45-50°C when I finally was successful applying it. The instructions also states you should allow the coat to cure for 10-15min before mounting the cooler, which is ok, but it increases the risk of dust particles sticking to the coat, just something to keep in mind.
I tested the compounds on a Q6600, running at 3.3GHz and 1.36Vcore, open case and water cooled (bowed ApogeeGT, Eheim 1048 and a heatercore with a single 120mm 1300rpm fan). I only tested full load (prime95 v25.3 SmallFFT test). Ambient room temp measured at radiator intake, and it was within 0.1°C between the two tests. CPU temps stabilize within 5min in this setup, so I only ran Prime for ~15min.
Not bad, a 2°C (3.6F) improvement on all 4 cores :) Too bad it's so hard to apply. Also the IC7 syringe, with the amount I used for this test, probably won't last for more than 2-3 mounts. Though I'm sure it depends on how good you are at applying the coat, as I made a bit of a mess. I'm probably going to restrict my IC7 usage to quad core CPU's, and more permanent builds, as this is too much work and also a bit more expensive than AS5.
I also wrote down the temps under FAH SMP, for those that are interested:
AS5, Core1/2/3/4: 58/54/48/51
IC7, Core 1/2/3/4: 55/52/47/49