After my XFX 8800GTX died , i changed it with one from BFG . XFX had black PCB , while BFG has green PCB . First thing i noticed was that the black and green 8800gtx have different memory.
The black one has GDDR3 from samsung ... Part number is : K4J52324Q

http://www.samsung.com/Products/Semi...dr3_060524.pdf

Samsung is rated at 1.8V and as you can read in Samsung's page , it goes up to 1Ghz


Picture taken from here : http://www.overclockers.co.nz/ocnz/r...tsn8800gtx0307

Now ... regarding the green 8800gtx .... It has GDDR3 from Hynix . The part number is : HY5RS123235FP

http://www.hynix.com/datasheet/eng/g...&SUB_RAM=512Mb

This ram is rated at 2.2V and 1Ghz speed .

http://www.xtremesystems.org/forums/...d.php?t=134267



... You can imagine my face when i tried to vmod the card and i was reading 2.2Vddr with the trimmer to it's max resistance ... Now i know the reason !!


I don't know which memory is better , but i would feel more comfortable with the samsung and 1.8V stock ... Maybe it gives you more overclocking headroom cause you can get it up to 2.0V+ without issues ... Dunno ...
I have also seen some very good memory overclocks with the green PCB , like this one : http://www.overclock.net/attachments...g?d=1172448743
http://www.overclock.net/nvidia/1362...thread-21.html


What's your experience and thoughts ??