Asus does not warrant uninterrupted or error-free operation of this product. Any technical or other support provided for the product under warranty, such as assistance via telephone with “how-to” questions and those regarding product setup and information will be provided without warranties of any kind. The warranty only covers failures or malfunctions occurred during the warranty period and in normal use conditions, as well as for any material or workmanship defect. The warranty will not apply if:
a: the product has been tampered, repaired and/or modified by non-authorized personnel;
By removing the heatsink the product has been tampered with and therefore it falls under that category. The warranty is void unless you have been authorized to work on it by Asus.
If you would like further information call Asus customer service. 1 (877) 339-2787
as long as you dont damage your card from a waterblock, there is no problem with removing the heatsink
That's the conclusion I've came to. Some of the members on OC.net have said Asus doesn't have a problem with it being how adding a water block is actually extending the life of the product. BUT the warranty explanation is written in a way that it's left to their discretion and reasonably so... I guess inevitably, it lies upon the person who receives the product and what type of day they are having.
as long as the card is not damaged due to the fact that you screwed up with the waterblock installation or that you have water damage, asus wont really care.
also note, i dont really see a point of putting a waterblock on a 670. it wont overclock any better to begin with due to the voltage limit and the carditself doesnt kick a lot of heat
Voltage can be modified. I did it on my previous 680 TOP's (which a fellow Toms member has one that runs stable 1328/7010MHz) and I've done it with my now current Gigabyte 780 WF3 (Gigabyte by default locks the voltage to 1.182v). The mod allows 1.215v which is plenty for 1200MHz most of the time even with cards with ASIC sub 70%.
For some reason the 670's do have a history of running hotter than the 680 and are notorious for throttling.