update and general advice for people considering buying /overclocking their 290's....
for the best benchmarking scores you'll find cards using Hynix instead of elpida gddr5 reach on average 300mhz higher when oc'd...
after much speculation by the bitmining community, 290's carrying Hynix gddr5 have also been proved to have better timings allowing them to do more work per clock cycle.
due to Hynix having a fire at their factory most AMD reference cards used elpida. as is the case with one of my cards possibly both.
benching with the stock cooler sees the 290gpu being throttled as the temps spiral to 90+degrees. there is also a bubbling effect of the paint in hot areas on the back side of the card...
so adding water cooling not only stops this completely but it also shows in games as everything seems to run much more fluid than it did before...
lastly Sapphire have recently released a new 290 tri-X oc. they use the amd reference card and as such the bios should be compatible with other early reference 290's.
im using the asus bios atm but I will experiment and run valley using both.
the NZXTx41 aio water cooling is by no means the same standard as the corsair varients imo.
the first thing I noticed was that both fans made irritating noises and the water block even made a weird sound... so I would advise buying the G10 bracket/VRM sinks/corsair aio watercooling.
the sounds have settled down now but the finished result is not what I expected. these are my first impressions from a retail sample. if things improve I will edit this post.
heres a few pics of the water cooling being fitted to one of my cards... im still working on clocks...
http://img.techpowerup.org/141008/20141007_100532.jpg
http://img.techpowerup.org/141008/20141007_113625.jpg
http://img.techpowerup.org/141008/20141007_115917.jpg
http://img.techpowerup.org/141008/20141007_141013.jpg
initial run
3360 290x at 1150mhz gpu/1295mhz mem up from 3197 max single card score...
and again single
290x@1180/1312 and still going...
290x@1190/1264 1point away from the next position up on the leaderboard...
290x@1200/1264 10mhz on core yielded an extra 17points.