My cooling appears to be limited by how quickly my radiator can dissipate heat. The Fujipoly at 0.5mm thick is plenty to have proper die contact with my CLC water block. For the sake of comparison, I did try using TIM+shim+TIM, but it made no appreciable difference for me in idle or load temps. For reference, the shim was an EK 7970 copper shim and the TIM was Arctic MX-2, properly applied.
Cooling aside, I will concede that for
pathological loads (read: Furmark) a higher power limit can be of benefit. I experimentally determined that a power limit of 50% (or actually, even 40%, YMMV) will prevent throttling versus a power limit of 20%. However, I would caution the average user who doesn't have proper cooling of GPU and VRMs against doing this, as even with my overkill VRM cooling (heatsinks + 120mm Scythe fan @ 90%) I was hitting 79C on the VRMs under Furmark as opposed to staying under 60C.
50% and 40% were within margin of error of each other, with no observable throttling in Furmark or in GPU-Z.
50%:
40%:
30% and 20% were hitting power limits and thus being throttled back.
30%:
20%:
Given my previous Heaven benchmark results showing negligible differences between 50% and 20% power limits and displaying no evidence of throttling in GPU-Z, I still wouldn't use 50% power limits for gaming without extreme cooling. For pathological use cases like Furmark or extreme benchmarking, it seems to eliminate another variable and can be used with proper cooling.
Dude... saying 'well it stays cool when I use X' is not evidence for X > Y. Also, MX-2 is not a modern nor high end paste. I mean you realize it's a 6 year old paste right, that wasn't even top of the line when it came out?
That's exactly like saying "Well I think the 7770 is way better than the R9 290x, because I tested it against the GeForce 8800!" There is no logic there at all. Sorry dude, but no one uses Fujipoly on there graphics cards or CPUs for a reason. You don't even use fujipoly on your CPU, because it's borderline retarded.
It's a thermal adhesive, it's an awesome tool when you need a
thicker adhesive for when you need to non-conductive, non-staining, non-permanently attach something to something else when a large gap is present and cannot be fixed by other means in a cheap way.
This is why fujipoly thermal pads are mostly used by companies to attach RAM and VRAM heatsinks. Enthusiast Users like us typically don't use them because spending $1 for a shim is really not a big deal, but it is a big deal to a company mass producing something, or for things that aren't performance utilized, like laptops for office usage.
Try using the shim again with a
modern paste, and you'll see your dramatic difference in temps. Not some outdated paste. You realize that they're on to
mx-4 now right? And mx-4 came out so long ago, it's considered a crap paste nowadays too.
There is seriously no difference between modern pastes. But there is a
huge difference between a modern paste, and some garbage that came out almost a decade ago. Gee, people will make fun of someone for using a 6xxx or Sandy Bridge or Phenom I, but have no problem applying stuff that's older than DDR2 on their most critical components! That's just insane!
Try some PK-3, Gelid, HeGrease, NH-T1, I mean there's a ton of great pastes. Or really, just get yourself some CLU which is dramatically better than the best ceramiques like PK-3.
Of course you aren't going to see a temp change from MX-2 vs Fujipoly. Try some PK-3 or HeGrease, and you'll see a massive difference (5C). Use some Coollaboratory Liquid Ultra, and the temp difference won't just be massive by thermal paste standards - it'll be massive by heatsink standards.
50% Power limit really is much more headroom than necessary, 7950s top out around 330, or ~30% power limit, in high intensity usage (which, sure, most users never do, but you still do it even if it's just a nanosecond in a game, a nanosecond that will be important, and not just because of murphys law). However, temperatures dramatically affect power consumption, as well as many other factors, so I'd really leave at least 35% power limit.
And having 30-50% power limit over 20% isn't going to be a massive performance boost, sure. But... why would you have your card throttle at all? Having any lower power limit is just kinda... dumb. You don't put a power limit on your CPU. Every modern board lets you set a power limit on your CPU, why don't you set a 20% power limit on your CPU? Because it's just be stupid, just set it to 100000% or whatever the max is or way above what it'd ever hit, and never worry about it.
However, I would caution the average user who doesn't have proper cooling of GPU and VRMs against doing this, as even with my overkill VRM cooling (heatsinks + 120mm Scythe fan @ 90%) I was hitting 79C on the VRMs under Furmark as opposed to staying under 60C.
79C is really not bad for VRM, unless they are crappy quality. I'd really only say 80-90C+ is where it's starting to get hot, and I'd only worry if you hear VRM whine or 110C+ on digital VRMs on non-budget components.
Of course, with raising the power limit, just like with anything, make sure you keep your temps in check. Even at stock speeds and with 0% power limit, 7950s can easily overheat.