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

[ehmdjii]

I'm going to write up a guide soon.

now that would be very cool! thx in advance!

[computerparts]

I'm going to write up a guide soon.

now that would be very cool! thx in advance!

The odds of getting a 1gb card that will unlock shaders when flashed is like winning the lottery. Even if you can flash it from modding it, it doesn't guarantee that you will be able to unlock the shaders. Most of the 1gb cards out there have the shaders laser cut (this is often referred to as hard locked) so they can't be unlocked no matter what you do.

[ovoskeuiks]

I have soldered a wire onto the BIOS chip to enable flashing and have flashed with a RBE modified BIOS. it has however made no difference to the performance of my sapphire 1G HD 6950 as I believe the extra shaders have been disabled when the chip was made.

[asher2]

Asher’s chewing gum 6950 mod.

What is this?

This is a hardware mod that allows you to flash your 6950 BIOS. 6950s can be thought of as coming in 3 flavours; those with a BIOS switch, those without a BIOS switch that allow flashing, and those without a BIOS switch that don’t allow flashing. This guide is for the last group. Always try just flashing first to see if it works. I STRONGLY recommend using atiflash for this, not winflash. This is because you may cause problems if you try with winflash and fail, but atiflash will generally just deny the flash and leave the card unchanged. This happened to me.

If you don’t know how to back up your BIOS and make a modified version, go find that out first!

So, whats the mod all about?

This mod is simply shorting some pins on an IC that allows you to flash your BIOS. This mod is temporary – you can remove it once you have successfully flashed your BIOS. I am going to go into detail for every step for those that are nervous about doing it. You can skip towards the end if you know what you’re doing.

What do I need?

Your 6950, a screwdriver, a small piece of wire, and some chewing gum.

Chewing Gum?

The credit for this mod goes to SlaveOnDope here. When I tried this mod, I had a lot of trouble looping the wire through the legs of the IC and stopping them touching the adjoining legs. Admittedly, it was in the wee hours of the morning and I was very tired. I came up with an easier method that gets the job done quickly and allows you to remove the mod easily even after you have replaced your cooler on your card.

Here is how it’s done...

This was done with a Sapphire series 6950. The procedure will be the same for all cards as far as I know.


http://img41.imageshack.us/img41/4293/dscn2656o.jpg
Here’s what the Sapphire card looks like, get a nice soft work surface to prevent damage.

http://img845.imageshack.us/img845/9822/dscn2657h.jpg
Unplug the fan.

http://img691.imageshack.us/img691/5749/dscn2658y.jpg
Flip the card over and remove the 4 cooler screws.

http://img39.imageshack.us/img39/4061/dscn2659mz.jpg
Separate the cooler from the GPU and locate the IC as indicated.

http://img811.imageshack.us/img811/3618/dscn2661j.jpg
These are the two pins that will be bridged across.

http://img18.imageshack.us/img18/9257/dscn2667a.jpg
Notice two things in this image. The first is that a tiny ball of chewing gum has been put on top of the IC – this is where the name ‘chewing gum mod’ comes from. Also notice that there is a small piece of wire below the card. This is about 1cm long with the plastic removed from each end and the ends bent at right angles. This is what we are going to use to bridge the legs of the IC.

http://img585.imageshack.us/img585/1033/dscn2654p.jpg
Stick the wire to the gum so that the bent ends touch the legs of the IC. It may take a tiny bit of fiddling to make sure the wire is in contact on both sides. I used tweezers as I was too clumsy with my hands.

http://img87.imageshack.us/img87/9081/dscn2676h.jpg
Put the cooler back on and flash your BIOS! Remember to plug the fan back in! You can see here that the mod is visible when the cooler is on. When you are done, just pull the mod off with tweezers or whatever without needing to remove the cooler again.

Good luck, have fun!

[dinzy]

How do these cards fail when you try to flash them unmodded?

I have an HIS card that will not flash and I am wondering if I can use a similar trick to unlock it

[GorgonSed]

Very interesting guide, thanks for posting!

[asher2]

How do these cards fail when you try to flash them unmodded?

I have an HIS card that will not flash and I am wondering if I can use a similar trick to unlock it

They fail differently depending on how I try to flash. With atiflash theres just an error message. When I tried winflash my PC locked up.

If you are flashing fine and the shaders are just not unlocked, then thats bad luck. If you are having an error with the flashing itself, then this trick will overcome it.

[SgtSpike]

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?

[asher2]

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.

[film2240]

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.

[pengram]

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

[asher2]

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.

[asher2]

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.

[italeffect]

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

[SgtSpike]

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.

[asher2]

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.

[Big Time Coin]

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.

[haploid23]

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

[cicada]

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

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

[onis_uk]

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 (

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