X800Pro VIVO pipelines unlocking still works?

Yes, use atitool or atitraytool to even have control about which temperatures and which fan speed.
Install a "silent' cooler (like zalman or ArcticCooling) and even benefit more...

Yes, you only might see some improvements when you tinker with memory timing.. but that is VERY dangerous (the XT-PE might have a bit more aggressive timings than the XT.)

 

Uhm, a note: after you flash to enable that extry quad your GPU will run hotter at the same speed. Just flashing the quad enabled and not changing your card's clockspeed will still result in your GPU running hotter....it's just got more going on now.

I used to crank up my stock cooler's fan using a third party app to help compensate for it.

Not a biggy, but make sure you realize that after flashing a pro to an XT that you are dealing with a different card. Also as Neliz points out different bios' have different levels of aggression on their memory timing, you have to do your homework and some experimentation to find out which will work best with your particular card.

 

I had one of the latest X800 Pro VIVO's and no matter what I did, I could not get the extra quad unlocked. I have heard that many of the latest cards are very had to transform into full 4 quad products.

 

Did you check it properly? 1.6ns on both sides of the board? if that was not the case upon purchase, it's a sure bet that the card won't be flashable