Hello all again
I have good news.
I successfully modified
Zotac PCI-E NV ZT-60206-10L GT640 Synergy 2G 128bit DDR3 900/1600 DVI*2+mHDMI RTL
To NVIDIA GRID K1. It is working fine. passthough works too.
BUT Device ID mofidication posible only after bios modification. Bios modification is needed only for specific vendors.
upd:
myweb found resistor places for Asus GT640-1GD3-L, no bios modification is needed. pic attached to post.
Benchmark:
http://www.ozone3d.net/benchmarks/furmark_192_score.php?id=121229Also I tested NVIDIA Quadro K600. it works.
http://www.ozone3d.net/benchmarks/furmark_192_score.php?id=121226I not tested NVIDIA Quadro K2000 but i think it will work too.
About modification:
all resistors are soldered at back side.
http://www.techpowerup.com/reviews/Zotac/GeForce_GT_640/images/back_full.jpgDevice id
GT640 0FC1
GTX650 0FC6
GRID K1 0FF2
Quadro K600 0FFA
Quadro K2000 0FFE
Initial values are:
index | meaning | resistance |
1 | 3 byte C D | 25k |
2 | 3 byte F | none |
3 | 4 byte values 0-7 | 10k |
4 | 4 byte values 8-f | none |
device name | R1 | R2 | R3 | R4 |
GT 640 | 25k | none | 10k | none |
GTX 650 | 25k | none | 35k | none |
Quadro K600 | none | 40k | none | 15k |
GRID K1 | none | 40k | 15k | none |
K2000 | none | 40k | none | 35K |
And you should use unlocked bios. Unlocked bios removed from post due to it is a copyrighted work.
To unlock bios you need to change masks and update checksum.
0000000010: 08 E2 00 00 00 04 00 00 ? 02 10 10 82 FF C3 FF 2F
0000000020: 00 04 00 80
to
0000000010: 08 E2 00 00 00 04 00 00 ? 02 10 10 82 FF FF FF 7F
0000000020: 00 00 00 80
and update bios checksum.
It is not possible to change device id without bios modification for this card.
it is may not necessary to change bios if you using other vendor gt640 card (not Zotac).
To check "is your bios good for hard mode" you need to do next steps:
1. Create boot dos flash with nvflash.exe tool.
2. Save bios by nvflash --save yourgt640biosname.rom (name should be 8 symbols max long)
3. Create a bios backup.
4. Open bios in any hex editor and check bios values at
0000000010: ?? ?? ?? ?? ?? ?? ?? ?? | ?? ?? ?? ?? FF FF FF 7F; ?? - any value is good
0000000020: 00 00 00 80
if values are equal your bios is good and you don't need to change anything. else step 4.
4. Change values to be equal values from 4.
5. Update checksum. I do it by nibitor tool. just open bios rom and save it. It produces lot of warnings, but it is ok.
6. Upload bios back to card.
Now you can change values by resistors