Decided to try some old gpu benching. Got 6600LE DDR3 for one benchmarking fun contest. And I'll try to max out everything from it, every single MHz
First of all, we need to get rid of weak DC-DC power convertor on card itself.
I had already few 4850 and 3850 Radeon's laying around here, so we already have where to get good power convertor :-D. New power convertor based on PWM controller uPI uP6201, supports two phase operation, output voltage from .6 to 2.5V, with rated current 60А. There is quad transistors per phase and doubled inductors to distribute power more effictively. More simple memory DC-DC based on uP6101, single phase with Vout from .8 to 80% of Vin (+12V here).
I don't need everything except power convertors on 4850's PCB, so cutted rest . Had some hard days trying to power convertor only from PCI-E, and made some hardware changes to it's control schematics.
At last got first output normal level voltages, 1.1V and 2.02V for mem. Tested current capability with piece of wire. Wire was burned away from currents >60A .
Well ok, let's move ahead.
First card to mount our power module - 7900GS with dead GPU convertor. Not sure if all card is still alive, but ohm checks of GPU and mem reported that they like alive (1 ohm and 27 ohm).
Tuned convertor to get 1.55V gpu output, and 2.25V for memory
Hook it up all together:
Wow, really hardcore ghetto look....final check before launch. Little afraid..
But it won't work. All power level's are ok, XTAL generates 27MHz, but card isn't working, not detected by PC.
Ok, nothing burns, connecting everything to 6600LE.
30min testing everything...not working....1 hour....not working.....all voltages are ok....1.5hours....Woah,, works...
Now it's working ok, installed Win7 with 6600LE + 4850 Power :-D
To be continue.
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Extremely impressive modding there! I hope there was at least something wrong with the HD4850 before you butchered it, but in any case, great going, can't wait to see results.
thats some impressive reverse engineering. now the question is what kind of performance are you going to get?
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Thats an awesome mod I could never hope to ever even attempt something like that.
6600 FTW. 6600GT was my first real graphics card after my GF2 MX.
Similar experience here
6600 regular (DDR2 lol) was my first nvidia card and the second that could somewhat handle some games.
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Assembling rig now, I have still 3 hardware mods to show :-P
Quote:
Originally Posted by slim142
Similar experience here
6600 regular (DDR2 lol) was my first nvidia card and the second that could somewhat handle some games.
Yeah, thats cool. I was parting out my neighbor's OLD computer and found this video card like nothing I have ever seen before, I popped the heatsink off and it was a Riva TNT2 64.
Old-school hardcore overclocking
. Had some hard days trying to power convertor only from PCI-E, and made some hardware changes to it's control schematics. 
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