Differences between 6950 and 6970

Hi there,

I was looking around for a comprehensive list of the (physical) differences of a 6950 and a 6970 (both reference designs).

Flashing a 6950 to 6970 is now a common sport. AMD is acting delayed, but will laser-cut the chips, that I'm pretty sure of.
So as anybody is flashing like crazy and shouts "Great! Now I have made myself a FULL 6970" I began to wonder - is a flashed 6950 *really* a 6970, or are there any differences left after the flash?


What I found so far are the following that distinct a 6950@6970 and a real 6970:


Power Connectors
(Source: can be seen with the eye)

The two cards have a different power-connector configuration.

6950: 2x 6 pin
6970: 1x 6 pin and 1x 8 pin

Open Questions:
- Is this a non-issue as these two extra are only ground lines?
- Does this create component stress??


Different PCBs
(Source: http://www.overclock.net/ati/893712-flashing-6950-6970-any-success-story.html)

- taken from above: different power connectors
- The 6950 PCB has some extra soldered resistors.
- The silver/blue caps are "E063..." for 6950 and "E059..." for 6970
- The large silverwhite block at the bottom left is "25CH10 X7" for the 6950 and "36CH10 A" for the 6970 (production date is in front, so these might either be different fabrication lines or actually different chips)
- other changes not visible in the small pictures

6950: http://www.xbitlabs.com/picture/?src=/images/video/radeon-hd6970-hd6950/29_695_pcbpw_big.jpg
6970: http://www.xbitlabs.com/picture/?src=/images/video/radeon-hd6970-hd6950/30_697_pcbpw_big.jpg

Open Questions:
- Effects with the different power demand of the 6970s BIOS higher clock speeds / power demand?
- Burnout due too high power consumption but smaller power delivery??
- Or are these related changes that simply come ftom the different power-connector configuration and have no otherwise effect?
- Do the "1.175V" of the 6970 BIOS translate to something completele different on a 6950 PCB? -> If so, maybe this fries the chips. If someone could measure this then we could recalculate what voltage on a 6970 BIOS has to be set to be within the power handling capabilities of a 6950 PCB


Different Memory Chips
(Source: http://www.xbitlabs.com/articles/video/display/radeon-hd6970-hd6950_4.html)

6950: H5GQ2H24MFR T2C chips which work at 1.5 volts voltage and 5000 MHz rated frequency
6970: H5GQ2H24MFR R0C chips (1.5 volts, 6000 MHz)

Open Questions:
- The 6950 chips might not be able to handle the higher clock rates that come with the 6970 BIOS (1375*4 = 5500 MHz)
- Damage due to higher voltage? (I heard the 6970 uses more juice on the RAMs, sadly I have no reference and no V-values)


Internal Device ID
(Source: RBE v1.27 released!)

Upon a BIOS flash the Device-ID remains intact, giving a flashed 6950@6970 card still the ID of a 6950.

6950: 0x1002 0x6719
6970: 0x1002 0x6718

Open Questions:
- Where is this information stored if not in the BIOS? Modifyable?
- Does this confuse drivers? tools?
- Drivers might detect a flashed 6950 and deny startup?


PowerTune Cap-Settings
(Sources:
for the caps: http://www.hardwarecanucks.com/foru...8899-amd-radeon-hd-6970-hd-6950-review-5.html
for not updating after BIOS flash: http://www.techpowerup.com/articles/overclocking/vidcard/159)

The PowerTune caps remain unchanged after a BIOS flash.

6950: cap at 200W usage
6970: cap at 250W usage

Open Questions:
- Where is this information stored if not in the BIOS? Modifyable?
- A flashed 6950 is still limited by its PowerTune settings, regardless of 6970 BIOS -- Maybe this is even a good thing?


So to anyone who thinks that he is unlocking a 6950 to a full 6970 - this (sadly) is simply not the case


Are there any more differences?
What are the impacts of flashing a 6970 BIOS on a 6950?
What about the open questions?


scooper

@jimmyz: actually i think they are pretty equal. I see only the 8->6 connector change and the field of resistors on the center/left. Both changed might actually be related.

@robal: thanks! I added the PowerTune differences. I already read the article but forgot about the PT

Edit: okay, I made out some more PCB differences, you as you pointed out:
- the silver/blue caps are "E063..." for 6950 and "E059..." for 6970
- the large silverwhite block at the bottom left is "25CH10 X7" for the 6950 and "36CH10 A" for the 6970 (production date is in front, so these might either be different fabrication lines or actually different chips)