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Discussion Starter #1
can anybody tell me what the difference is between these to card. I keep reading about "how" to unlock it but not much on why and what the benefit(besides the obvious financial aspect)
 

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A 6950 is almost the exact same card as a 6970. The have the same PCB so they share all the same circuitry.

But AMD needed to differentiate the cards so they simply disabled some shader units and lowered the clocks for 6950. Luckily these changes were made to the bios so with a 6970 (or a modded 6950 one) bios you get back all the functionality of a 6970 but for cheaper.
 

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Discussion Starter #3
Quote:
Originally Posted by sexybastard;13100271
A 6950 is almost the exact same card as a 6970. The have the same PCB so there share all the same circuitry.

But AMD needed to differiante the cards so they simply disabled some shader units and lowered the clocks. But these changes were made to the bios so with a different bios you get back all the functionality of a 6970 for much cheaper.
so you're saying, that as far as the hardware configurations goes, there are no differences, only that some of the shaders were disabled?

guess I'm going with two 6950s then
 

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Short simple answer: A 6950 unlocked is no different from a normal 6970.
 

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Quote:


Originally Posted by InterestedThirdParty
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so you're saying, that as far as the hardware configurations goes, there are no differences, only that some of the shaders were disabled?

guess I'm going with two 6950s then

Hardware: A 6970 has a 6/8 pin whereas a 6950 has a 6/6 pin connector.
 

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Quote:


Originally Posted by InterestedThirdParty
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so you're saying, that as far as the hardware configurations goes, there are no differences, only that some of the shaders were disabled?

guess I'm going with two 6950s then

Yep.

All reference cards can be unlocked. Most non reference cannot.

Actually the one difference in the the hardware is that the 6970 comes with an 8pin + 6pin while the 6950 has 2 x 6pin. But this is not a big deal since the extra two wires on an 8pin are ground so they don't really add any extra power.

Get two reference 6950's and unlock them. You will thank your wallet.
 

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I believe the RAM IC's on the 6970's are more capable/higher voltage than those on the 6950's.

Hence the plethora of people unable to hit 6970 memory clocks on their unlocked 6950's.
 

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Quote:
Originally Posted by kidwolf909;13100384
I believe the RAM IC's on the 6970's are more capable/higher voltage than those on the 6950's.

Hence the plethora of people unable to hit 6970 memory clocks on their unlocked 6950's.
I'm fine with this - increasing the ram past 1350 does literally nothing for my framerates and almost nothing for benchmarks (which I have later realised is to do with ECC
smile.gif
)

You're right, though. And I believe the 6970 ram runs at tighter timings as well.
 

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Also, 1GB 6950's cannot be unlocked. Different Arcitechture.

It's like the 5850 and 5870 though. You could overclock the 50 to the speed of a 70 but the 70 would always win because it had 1600 Streamed CPU's on the actual PCB/GPU chip and it's little brother had only 1440 of them.

But..the 6950 2GB Ref is the bang same as the 6970. It is a 6970 with a different bios flashed. That's all!
 

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A few people a while back where having problems when flashing a 6970 BIOS to the 6950, the VRAM on the 6970 runs at tighter timmings, there are some BIOSes about that just unlock the shaders, no noticeable difference than a 6970 even though the VRAM will be running a tiny bit slower. After the unlock you have to OC to 6970 speeds I believe.
 

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Quote:
Originally Posted by BradleyW;13100473
But..the 6950 2GB Ref is the bang same as the 6970. It is a 6970 with a different bios flashed. That's all!
This is technically incorrect.

The 6950 has what appears to be a cluster of resistors which are absent on the 6970 (see this picture). I also believe it uses physically different ram chips.
 

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Almost no 6950 will run faster than 1375mhz without error correcting. Most benchmarks like 3dmark11 aren't affected by the error correcting, so many people wrongly assume their card runs fine as their score increases.

I've found Heaven with tessellation disabled is the best way to determine error correction. However, when you get to a certain speed, you will begin to gain fps due to the raw power compensating for error correction.
For example (figures are not accurate and just for illustration):
1375mhz - 45fps
1400mhz - 43fps
1425mhz - 44fps
1450mhz - 45fps
1500mhz - 46fps
 

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Per my understanding, RAM timing and rated frequency is different as well on the 6970. If I am to guess, overclocking head room is more on the 6970.
 

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Quote:
Originally Posted by whybother;13100552
Almost no 6950 will run faster than 1375mhz without error correcting. Most benchmarks like 3dmark11 aren't affected by the error correcting, so many people wrongly assume their card runs fine as their score increases.

I've found Heaven with tessellation disabled is the bet way to determine error correction. However, when you get to a certain speed, you will begin to gain fps due to the raw power compensating for error correction.
For example (figures are not accurate and just for illustration):
1375mhz - 45fps
1400mhz - 43fps
1425mhz - 44fps
1450mhz - 45fps
1500mhz - 46fps
+rep to you. This is EXACTLY what I observed when I was benchmarking with Heaven 2.5 (with tesselation normal though. I could comfortably go past 1400, but observer lower/no change in performance. So, dropped it down to 1350 (see sig rig) and was the sweet spot for me.
 

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There are marginal differences such as for example the higher Memory Bandwidth of the 6970 or tighter Memory timings.
Those marginal differences do however not impose a difference in performance between the 6950 and the 6970.
You can imagine a 6950 to basically be a downclocked 6970 with very slight changes in the interior.
An overall look of the differences here:
new.png


Also it is clearly shown by a techpowerup review that a 6950 which has been Shader unlocked to 1536 shader units + overclocked to the stock speeds of a 6970 performs equally to normal Stock 6970:)

Untitled.jpg
 

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Quote:
Originally Posted by fluxlite;13100550
This is technically incorrect.

The 6970 has what appears to be a cluster of resistors which are absent on the 6950 (see this picture). I also believe it uses physically different ram chips.
Except for the resistors and a change in where power is directed to, i believe the memory chips may also be just a better batch, high class of the same class if you get what i mean. Also, people who get lower fps with overclocked Vram, i've noticed this on many ati cards i've had in the past.
 

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I wouldn't take any Heaven results too seriously.
Game benchmarks show that heavy tessellation works Radeons and bogs down thier overall performance.

As far as the two GPU's, I would pay the extra and get the 6970, but thats just me.
Not all 6950's unlock, flash and overclock so well and even when they do your still missing out on some power/agility the 6970 has, and even then your only at stock 6970 power which is not impressive.

If trying to save money the 6950 is a great choice though.
 
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