I know that Micro$oft went back to the 1st gen GPU heatsink for the Jasper Kronos for some reason. I heard multiple rumors like the 2nd gen heatsink wasn't needed any more, it was a cost saving measurement, and the one that kinda freaks me out, but I don't really believe... It caused uneven cooling which resulted in the E74. I personally thought that the heat pipe worked quite well. Since I installed an 80mm case fan into my 512mb Jasper, I figure that if I up/downgraded to a 2nd gen GPU Heatsink I would get the most efficient cooling with the 80mm fan if it was blowing on the extended pipe heatsink... I have a ton of the old 2nd gens laying around but I'd like other people's opinions first before I do it. So what do you think?

Both of the first reasons are true. The Jasper GPU does not need the 2nd gen heatsink, and as an added benefit, it saves microsoft money. Jaspers being the most reliable 360s to date, I'd say you would be wasting your time replacing that heatsink, but it won't hurt anything so have at it. While you're at it, you can put a first gen CPU heatsink on there instead of the 2nd gen because the first gen has more efficient cooling (switched to 2nd gen when they reduced the power consumption of the CPU in falcon models because they didn't need as much cooling and aluminum is cheaper than copper).

So in summation, you'll get the best cooling from the same heatsinks that were shipped with Zephyr Xboxs.

CPU: 1st gen>2nd gen
GPU: 2nd gen>1st gen
Jasper>All

EDIT: Also, adding extra fans will just mess with the airflow of the fans that are there. If you want better airflow, modify the stock fans to run at 12 volts (not that you even need to do this with a jasper either lol)

I never thought about the 1st gen CPU heatsink being more efficient (have a lot of those laying around too), it actually makes sense, the way I have my system setup to pull cool air from the front over the GPU from the cut out memory card slots Which is now a vent, and I actually originally installed the 80mm fan because it was the right price and it looked cool, but I'm on a mission to keep my 360 at near room temp all the time, so any way to cool it more is good for me, ive had the foiltape mod on it since i started modding it. I'm even planning on making plexiglass airflow shrouds to improve the flow even more. I'm going to RGH this one when the BB DemoN comes out, so I want it to stay cold. I have 5 Jaspers for a reason, I love them and I'll never go to a slim and they are sooo simple to mod! So I think I might just do all of that and see what happens.

Ahh great! That cut out of the memory ports is probably the best air flow mod out of ANY that I have seen. Props for having the sense to do that and not just throw a fan on the side like all the other kids out there.

Yeah I actually think the Slim failure rate is higher than the Jaspers. I wish I had a jasper. Maybe I'll try to pick one up soon. I haven't seen one up close in a while. I miss them.

The second gen jaspers are the ones that are patched with the SMC exploit.

I own one and I have till this day, got no problems.

It so quiet that im sitting next to it and i sometimes forgot to turn it off lol.

I installed the zephyr heatsinks and made a center divider in the fan shroud with a piece from an extra shroud, hot glue and J-B Kwik... After redoing the foil tape mod there is Twice the air flow on the CPU side with the case fan and now I just wish I could get more flow on the GPU side. I might re think the grill on the face plate and go for a less restrictive mesh... But I dunno yet... I runs super ice cold now!