AS5 on 2500m GPU --> Higher Temps?!

In short: My e1705 with a quadro 2500m is idling at temperatures at least 10 degrees celsius higher than it was before: 70 degrees with slow fans compared to ~60 with slow fans (I had fans kick in at 65 to bring it back to 60). There have been no hardware/software changes to the system.

So I read the guides about applying AS5 to your GPU and I thought I'd try to get better temps. I cleaned off all the old compound from both the GPU and the heat spreader, and placed about a pea-sized piece on the GPU (see attachment). It wasn't the most perfect blob of AS5, but volume-wise I think it was pretty close, and ideally it would be smoothed out when I tightened the screws on the heat spreader. I stuck to a "less is more approach" having heard that all I needed to do was fill the minor imperfections of the contact surfaces.

So what gives?

I did notice the copious amounts of thermal compound that I had to scrape off to clean the surfaces. My theory is that the thermal compound filled the gap between the GPU and the surrounding black square structure (visibile in attachment), and helped conduct heat laterally away from the GPU, instead of just through its face. The copper face on the heat spreader is much larger than the GPU, which tells me that more lateral heat spreading is needed.

Also, I was wondering if anyone has experience undervolting at idle for the GPU. I might not have a chance to fix this right away and I want to do everything I can. I added speculative voltages to the attachment, because .06V increments would make sense to fill the gap between 1 and 1.24.

Any thoughts? Thanks in advance.

Thanks for the response. I'll have to take it apart this weekend to see how the paste distributed itself.

In the meantime, does anyone have experience with undervolting GPUs? I was hoping I could go below 1V for the 2D clocks, but those options are not (at least directly) available.

I'm a little red in the face at having messed around with this stuff because, from what I can tell right now, I've killed the thing. I used the "half a grain of rice" that the manufacturer recommends, and I spread it nicely with a credit card. Booted up to 100 degrees C on the desktop! I quickly shut down and disassembled the card to put on a more substantial layer (I think the surfaces are rough enough to warrant it) and now the laptop won't even POST (stays on for about half a second). I removed the video card and it appears to boot fine (not that it does me any good).

I'm not sure that I fried it, as I know these cards have built-in safeties. I think I may have shorted it, because I discovered some thermal paste on the PCB outside of the GPU area. I've already bought a replacement off ebay, I'm just wondering if there's any hope for the card I've got.

One thing's for sure: I'm never going to mess around with that stuff again. To begin with, the stock GPU paste is some kind of adhesive, as opposed to AS5, which will never harden. I wasn't doing an apples-to-apples mod, and I think that may have been the source of my problems.