flashing a 6950 with 1GB using the 6970 with 2GB BIOS

cicada

full member

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Quote from: AlexWaters on August 01, 2011, 08:24:59 PM

Anyone else try this with the Sapphire 1gb 6950 without bios switch?

I've done it with an XFX 1GB 6950 - it allowed me to flash properly but didn't have any luck unlocking shaders. From what I've read the Sapphires should allow flashing the BIOS the same way, but it's a gamble whether or not you'll get lucky and unlock shaders..

I just used a circuit-writer pen to mod a second card:

Allowed me to flash the card with no problem again, but no unlocked shaders on this one either.

I'm not certain if I'm going to bother modding my other two cards, the heatsinks only came off these two so I could re-do the thermal paste.

[edit]

fancy smartphone camera makes an amazing magnifying glass Wink

This is also removable with a cotton swab and a bit of acetone.

AlexWaters

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Twitter:@watersNYC

Anyone else try this with the Sapphire 1gb 6950 without bios switch? I have two - and had the same error when I tried flashing in DOS. I don't want to risk bricking my cards again if it's impossible to unlock the shaders - even with an accepted flash.

Asher, do your successfully flashed cards now show the 1536 shader count?

Big Time Coin

sr. member

Activity: 332

Merit: 250

I was thinking about trying this mod, but no one seems to have success with it yet besides you asher. And you only got it to work on 2 out of 5 cards? What kind of results did you get with it?

asher2

newbie

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I'm glad to see people getting use out of the mod!

As an above posted mentioned, solid core wire is much better to use. I didn't happen to have any handy at the time. You can get it from ethernet cable (not all) or breadboard jumper cable. Those are the easiest places to find it.

Jack of Diamonds

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Quote from: ehmdjii on July 19, 2011, 03:03:26 PM

so after all i did manage to use this physical mod to flash my sapphire 1gb.
i used winflash and i said flash was ok!

unfortunately i still only see 1408 shaders instead of 1536 Sad

That's because the worst binned 6970's become 6950's.
I.e. the last shader units are of very poor quality and are physically burned off from the GPU die with a laser.

Some 6950 GPUs are fully functional 6970's, artificially binned as 6950's to meet market demand.

Whether you get one of these units is just a pure luck of the draw. Just about all of the 2GB versions can be unlocked & AMD even included a BIOS switch for that purpose

GPUs in the 1GB versions are mostly the poorest yields at TSMC that are not fit to be full 1536 shader GPUs but not weak enough to be fully discarded/downgraded into 6870 GPUs with even more shaders cut off
if you do a hard mod by soldering & get lucky with a relatively good chip it might work, but with a much lower success rate than the 2GB ones

For you to see the full 1536 shaders, they need to be there physically, if not you will only see 1408 even after a successful flash

haploid23

legendary

Activity: 812

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i just got a brand new powercolor 6950 1gb, good thing is that it's flashable with no hardware mod, but i couldn't unlock the shaders. oh well, it's 1gb version so i didn't really expect shaders to unlock. i just wanted it to be flashable without hardware mod, which it was

ehmdjii

sr. member

Activity: 351

Merit: 250

so after all i did manage to use this physical mod to flash my sapphire 1gb.
i used winflash and i said flash was ok!

unfortunately i still only see 1408 shaders instead of 1536 Sad

cicada

full member

Activity: 196

Merit: 100

Quote from: onis_uk on July 18, 2011, 01:16:57 PM

i did this mod a few weeks ago on my 2gb Sapphire hd6950... it allowed me to flash with a modded bios
from my original bios (modded with rbe) but after a reboot the card still had only stock shaders Shocked

(

most rubbish..... when people say they are "laser cut" are they referring to the gpu die its self ?!

It's hit or miss whether or not the shaders will be available on any given card, even two cards in the same model/revision.

Nobody knows for certain how the shader cores are disabled on these cards, the people insisting 'laser cut' are talking out their ass or parroting someone else who was talking out their ass Wink

When you see 'laser cut' you can assume this to simply mean 'disabled in hardware' until someone can confirm.

It's also possible the disabled shader cores are simply non-functional on many of these cards, bottom-binned so to speak.

onis_uk

full member

Activity: 131

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i did this mod a few weeks ago on my 2gb Sapphire hd6950... it allowed me to flash with a modded bios
from my original bios (modded with rbe) but after a reboot the card still had only stock shaders Shocked

(

most rubbish..... when people say they are "laser cut" are they referring to the gpu die its self ?!

cicada

full member

Activity: 196

Merit: 100

Used the 'bubblegum' mod on one of my XFX 1GB 6590 ZDNC, worked like a charm but it's a big PITA to get placement right!

Instead of bubblegum, I used a chunk of window sealant putty and a bit of solid-core ethernet wire, works the same and you don't have to chew on it first Wink

Shaders didn't unlock but the flash took with no problem at all.

I'm going to pick up one of these circuit-write pens instead for the other 3 cards: http://www.radioshack.com/product/index.jsp?productId=3964901

haploid23

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Quote from: Big Time Coin on July 15, 2011, 03:04:25 AM

Wow asher, you've got some balls to do that to your card! How did you figure out those pins needed to be shorted? How are you going to reverse it to take advantage of warranty without them being able to tell you did it? Shaders unlock gives you about 40 more Mhash, but I don't know that it's worth voiding the warranty like that. Kudos.

he can just put the wire and gum back and reflash

Big Time Coin

sr. member

Activity: 332

Merit: 250

Wow asher, you've got some balls to do that to your card! How did you figure out those pins needed to be shorted? How are you going to reverse it to take advantage of warranty without them being able to tell you did it? Shaders unlock gives you about 40 more Mhash, but I don't know that it's worth voiding the warranty like that. Kudos.

asher2

newbie

Activity: 40

Merit: 0

Quote from: italeffect on July 07, 2011, 01:14:32 AM

Has anyone else had success with this? I've tried two 1GB 6950's and not been able to make it work... (using the hardware mod detailed above)

Sapphire 6950's purchased last week

Not been able to make it work meaning what? If the flash wasn't work, then you're doing something wrong. If the flash works but the shaders aren't unlocked, then you are out of luck.

SgtSpike

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Activity: 1400

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I found out that the Sapphires I tried to flash were unflashable. I haven't tried the physical mod that asher2 posted, but that takes some guts. I just settled for an overclock that netted about 350MH/s per card.

italeffect

sr. member

Activity: 255

Merit: 250

Has anyone else had success with this? I've tried two 1GB 6950's and not been able to make it work... (using the hardware mod detailed above)

Sapphire 6950's purchased last week

asher2

newbie

Activity: 40

Merit: 0

Quote from: pengram on June 29, 2011, 11:13:35 AM

i've heard 1GB versions can't be unlocked hmm

Well, that is false :p

I'm not saying all of them can, but many of them certainly can.

asher2

newbie

Activity: 40

Merit: 0

Quote from: film2240 on June 29, 2011, 09:37:29 AM

Quote from: BrianH on June 23, 2011, 04:12:44 AM

If you want modding/overclocking options, ask on an overclocking forum (i.e. EOCF).

A 2GB card likely will have different memory timings, memory, size, etc. programmed into the bios that all could bork your card. Your 1GB card is not capable of running these settings at default.

I think this poster is right on this one.Flashing a BIOS on hardware that's not made for it will have nothing buit problems anyway. The only feasible way I see is to export a BIOS copy with RBE,(and then make sure to have 2 copies,1 stock and 1 modded copy-with shaders unlock),then unlock shaders in that program then flash it back,the success rate is higher than flashing a different hardware's BIOS on though,as you're simply flashing the same hardware's BIO except with the extra shaders unlocked,therefore boosting performance and crunching power for mining BTC.

I hope this helps.

I agree. Use a modified version of the BIOS on your card, not the BIOS from another card.

pengram

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i've heard 1GB versions can't be unlocked hmm

film2240

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Freelance videographer

Quote from: BrianH on June 23, 2011, 04:12:44 AM

If you want modding/overclocking options, ask on an overclocking forum (i.e. EOCF).

A 2GB card likely will have different memory timings, memory, size, etc. programmed into the bios that all could bork your card. Your 1GB card is not capable of running these settings at default.

I think this poster is right on this one.Flashing a BIOS on hardware that's not made for it will have nothing buit problems anyway. The only feasible way I see is to export a BIOS copy with RBE,(and then make sure to have 2 copies,1 stock and 1 modded copy-with shaders unlock),then unlock shaders in that program then flash it back,the success rate is higher than flashing a different hardware's BIOS on though,as you're simply flashing the same hardware's BIO except with the extra shaders unlocked,therefore boosting performance and crunching power for mining BTC.

I hope this helps.

asher2

newbie

Activity: 40

Merit: 0

Quote from: SgtSpike on June 28, 2011, 11:51:38 AM

I have a 6950 that can't flash... it says "cannot erase rom" when I try to flash it using winflash. So this mod would fix that issue?

Yup.

Topic: flashing a 6950 with 1GB using the 6970 with 2GB BIOS (Read 18890 times)