8800GTS locked mem-controller, ideas and unsuccesful practice:)

[TiN_]

Memory controller of NVIDIA G80 is made from six 64-bit channels. This is also visible in model range of existing cards, 8800GTS, which have blocked 1 channel and have no 2 memory chips.Total bus width cutted from 384 to 320bits. 384-64=320 So one of memory channels is disabled on such cards. Which exact memchannel is disabled marked on GPU IHS top. Number after letter K in line “G80-100-K0-A2” is the key. Here you have image for reference. total 6 channels (from 0 to 5)



"Full" cards like 8800GTX\Ultra\Quadro working with all 6 channels, so their chips have no any letters “–Kx”. Most popular cards with disabled "0" channel, Lurking in the web show off some other rare variants, with G80-100-K1-A2, and G80-100-K3-A2 and G80-100-K5-A2. All these cards are 320bit 320MB versions.

So we get the question, is it possible to enable all memory controllers, buy soldering extra chips and flashing BIOS in home environment?

To get practice with this I've got dead (crappy GPU) Radeon X1900XT 512MB, which have 8 mem chips SAMSUNG K4J52324QC-BJ11. These IC's are mostly the same as used in mine 640MB GeForce 8800 GTS, difference is only in timings (1.1ns Radeon vs 1.2 8800GTS) and nominal voltage.



Soldering chips was made in a horror way, by electrical owen from ancient 196x's This metodic was twice tested by me earlier (here russian description with photos) for _SUCESSFUL_ replacing chips NVIDIA nForce4 SLI\Ultra on two motherboards DFI LanParty NF4.





Except memory chips, there also passive resistors and capacitors necessary for normal videocard operation, which was not placed with 2 memories. Soldering them was made by usual iron with sharp tip and binoculair microscope MBS-9. After all these things I've installed card into PC and turn power on. No artifacts, it is working! Ok, flashed original BIOS from Quadro FX 4600, which have total 768MB and 384-bit memory bus. But unfortunely, I've got just Quadro FX 4600 with 640MB and 320bit.

So don't try to add memory to your 8800GTS, G80 on these cards have fully blocked controller. TESTED by me

P.S. Of course, we can try to replace G80 chip from GTX card to GTS PCB, and AFAIK, this will render working GTS 768MB 324bit with even 128SP, but have no any working GTX-chips
P.P.S. sorry for watermarks on photo, I've used this material for russian online site in mine EVGA 8800GTS ACS3 card review.

TiN.

[nullface]

Hooah 5 stars from me
Had the same idea, but i dont have anything near the skills to do a mod like this or the tools

[ineedaname]

Wow I have no clue how u managed to solder that onto the board. Good job man!!!

Even thought it didn't work u still answered an important question.

[rbsmontemor]

Yeah good job. I have no ideia how you soldered that BGA chips

Rbs.

[RAW-Raptor22]

Could you add memory by changing the 32MB modules with 64MB or 129MB ones?

[TiN_]

Raptor22

It's possible, but cheaper to change 320MB to 640MB variant

[RAW-Raptor22]

Raptor22

It's possible, but cheaper to change 320MB to 640MB variant

Can you get high speed (2200MHz DDR?) 128MB modules? that would rock.

[TiN_]

As I sad, it will be less expensive just sell your current card and buy GTX one. Really cheaper than building custom GTS with 0.9ns memory.

[RAW-Raptor22]

As I sad, it will be less expensive just sell your current card and buy GTX one. Really cheaper than building custom GTS with 0.9ns memory.

Yeah, ur right.... too bad Im poor...

[wittekakker]

Like I though, not really worth the risk, though mod still rocks!
Nice skills (y)

[4Qman]

TiN_EOF you amaze me dude. Awesome work as usual.

[TiN_]

4Qman,thanks mate, nice to see you again

[hvtecgr]

Amazing tin!!Goooooood job!!! Is it possible to explaine some tips in english how to unsolder something like this???

[TiN_]

Thanks a lot, unsoldering is not a big deal. Just put card on some kind of heater with temperature range 220-250C, and wait for few mins. When solder melts - take off chip and you are done Soldering chips on PCB is much more complicated, especially used chips.

[hvtecgr]

Unsoldering sounds really easy!!!For soldering the chips you used hot air station???

[HamidFULL]

Nice but forget these thing and find a way to unlock our 8800 GTS stream processor to 112 or even higher

[TiN_]

No way to unlock, it's locked by hardware. Just replace GTS chip with GTX one

[HamidFULL]

No way to unlock, it's locked by hardware. Just replace GTS chip with GTX one

8800 GTS is Unlockable look here :
http://www.xtremesystems.org/forums/...d.php?t=164195

[TiN_]

HamidFULL

Really?? G92 GTS is a WAY different than GTS G80, and... answer to your question: Yes, 8800GTS 96/112sp can be EASILY unlocked... By NV tech engineer with enough right's and inside NV equipment. I'm sure it's done in few seconds with some kind of software+hardware.

[HamidFULL]

HamidFULL

Really?? G92 GTS is a WAY different than GTS G80, and... answer to your question: Yes, 8800GTS 96/112sp can be EASILY unlocked... By NV tech engineer with enough right's and inside NV equipment. I'm sure it's done in few seconds with some kind of software+hardware.

yes really really!

I hope that one can find a way and Damn Nvidia!

[TiN_]

Yes, the way is easy: find and hijack senior engineer from NV and make him to build programmer for you :-D

[wittekakker]

Probably hard-modded in the GPU package, not just something that can be done and undone through software. At least, that is what seem to be most obvious for me, might not be how it is in real life.