I've seen a few posts suggesting people post their temp results when silencing the v1.0 xbox, so here goes.
all i do is run xbmc so can't post on games. all temps after running a movie for an hour or so, ambient temp about 18C
original temps: cpu 46C (115F) GPU 36C (97F) - original noise - like a screaming jet airplane next to your tv
temps after the mods (below): cpu 54C (129F), gpu 44C (111F) - these temps are with fan at 20%.
after mod noise - like a feather gently settling on a pond. well ok a bit more than that but SO QUIET i had to look to see the fan was turning. its still quiet at 100% (but i haven't done temps at that)
so it got hotter and much quieter. now from what i've read these temps are still ok - i've read 60C/150F about max - any views on this? and xmbc will increase my fan % when summer arives. So am i sweet? i hope so.
the mod: based of the various tutorials (read them all before you decide how to attached your fan)
- replaced the v1.0 gpu hs and fan with a v1.1 hs without fan off an old board
- removed ms pink goo on gpu and cpu hs (used acetone based nail polish remover followed by 100% isopropyl alcohol) and replaced with arctic silver 5
- replaced cpu fan with 80mm silenx ipx-54-14 fan (34cfm, 14dba). i plugged this fan into the motherboard connector so it is controlled by xbmc. ie i did not do the 12v fan mod (tho if i were a gamer i likely would add a switch) its a low speed fan (1700rpm max) so the 20% setting may not shift much air.
the only tricky bit was after grinding the slot in the hdd tray i had to grind a bit out of the leg of the dvd-rom tray that sits next to the fan... at first i didn't, but noticed the tray leg pushed the fan over and distorted the shape so that the fan blades touched the fan sides. i think the silenx fan is quiet bulky. with the various fan bits ground off it slotted well into the existing case clips for the old fan. one tutorial suggests you cut these case clips off - i'd suggest you see if they can hold your new fan first as it worked for me. i used cable ties at the top with some thin duct tape to reduce vibration with the metal case. cut the metal fan grill out and expanded the back air slots...
I am very pleased and now love silenx fans. if you've got a v1.0 with xbmc i recommend it