6970 vs 6950 at the same clocks

[Skurge]

http://www.xbitlabs.com/articles/video/display/radeon-hd6970-hd6950.html

The extra shaders in the 6970 seem to be doing nothing. A bottleneck somewhere or unoptimized drivers?

 

[Smartazz]

If I recall correctly, something similar happened with the HD5870 and 5850 so I think it's probably unoptimized drivers.

 

[Skurge]

Could also be why the 6950 is so close to the 5870.

 

[AtenRa]

The shader difference between 6950 vs 6970 is 2 SIMDs as in 5850 vs 5870 but with the Vec-4 is only 2 x 64 = 128 shaders vs 2 x 80 = 160 shaders in Vec-5, so at the same clocks 6950 should be close to 95-97% of the 6970, same as 5850 vs 5870.

 

[Lonyo]

The shader difference between 6950 vs 6970 is 2 SIMDs as in 5850 vs 5870 but with the Vec-4 is only 2 x 64 = 128 shaders vs 2 x 80 = 160 shaders in Vec-5, so at the same clocks 6950 should be close to 95-97% of the 6970, same as 5850 vs 5870.

Close, yes, but an 870MHz core (5880MHz RAM) HD6950 is faster than an 880MHz HD6970 (5500MHz RAM) in some situations, and pretty much 99% in most others.

That means it's quite possibly RAM/bandwidth limited in my book, not necessarily core limited.
Marginally slower clock and less shaders with faster RAM is faster than more cores and higher core clock but slower RAM.

 

[MrK6]

Close, yes, but an 870MHz core (5880MHz RAM) HD6950 is faster than an 880MHz HD6970 (5500MHz RAM) in some situations, and pretty much 99% in most others.

That means it's quite possibly RAM/bandwidth limited in my book, not necessarily core limited.
Marginally slower clock and less shaders with faster RAM is faster than more cores and higher core clock but slower RAM.

Probably within the margin of error TBH, although there are a few instances where it doesn't seem like it is. In those cases, I would guess there are other portions of the chip that are overclocked too and allow some synergistic action to go on.

Thanks for posting Skurge - once again Xbit delivers :thumbsup:. This seems like a dead repeat of the 5850/5870, although AMD is only asking for a much more reasonable $70 for the faster part this time. Still, it seems everything is about clock speed again. One of the most surprising things I saw from the review was the power draw on the 6970 - 60W higher than the overclocked 6950? Seems like the 6950 is a no-brainer here. The only thing that remains to be seen is overclocking ability. A 5850 @ 1050MHz is a 45% overclock. That is one hell of an engineering accomplishment to trump. Still, I'd like to see 6950's do the same, maybe even 1.1GHz.

Has anyone seen such feats? I've been looking for user reviews of 6950's on water, but so far have come up with nothing.

 

[Triggaaar]

Has anyone seen such feats? I've been looking for user reviews of 6950's on water, but so far have come up with nothing.

What, with locked voltage?

 

[notty22]

In another forum, a user had checked the specs of the memory modules used in the 6950/70. The 70 uses slightly different spec d memory part. rated at 1.6 v vs 1.5.
So the bios probably is tuned to give it a hair more voltage, I'm guessing thats part of where the extra power is being used.

 

[MrK6]

What, with locked voltage?

No hard mods? Did software voltage control turn enthusiasts into a bunch of Sallies?

In another forum, a user had checked the specs of the memory modules used in the 6950/70. The 70 uses slightly different spec d memory part. rated at 1.6 v vs 1.5.
So the bios probably is tuned to give it a hair more voltage, I'm guessing thats part of where the extra power is being used.

Especially with 2GB @ 1.6V, yikes. Bring on GDDR6 :awe:.

 

[Lonyo]

Well the AT review said that board partners would probably be coming out with custom designs which were unlocked in CCC, so it wouldn't be entirely necessary to hardmod. At the moment it seems all locked down for now. Might as well wait until partners come out with some custom elements since AMD seem pretty friendly with these cards towards overclockers.

 

[MrK6]

Well the AT review said that board partners would probably be coming out with custom designs which were unlocked in CCC, so it wouldn't be entirely necessary to hardmod. At the moment it seems all locked down for now. Might as well wait until partners come out with some custom elements since AMD seem pretty friendly with these cards towards overclockers.

I was just commenting to see if anyone had gotten antsy and gone for the hard mod (I checked XS, found nothing ). It wasn't long ago that high-res board shots and a hardmod would already be ready prior to NDA lifting

 

[Dracolich1970]

This is a great 560 review from probably one of the best testers outthere.

Power Consumption and temperatures

http://www.hardwarecanucks.com/foru...-nvidia-geforce-gtx-560-ti-1gb-review-18.html

Overclocking results(which includes 6950@855, and GTX 560@991.

http://www.hardwarecanucks.com/foru...-nvidia-geforce-gtx-560-ti-1gb-review-19.html

I am a ATI guy and have been for years, but for once I am leaning towards a Nvidia card. I am still contemplating between a 6950 for unlock or a GTX 560 Gainward Phantom 2 gb. I want a nice cooler, and thought about the MSI Twin Frozer(though can't be unlocked, which negates that part).

Any suggestion might help out.(The little price difference in my country will not have any major significance.). What matters is: Silent, at least at the level of my 4870x2 in performance, and somewhat cheap if I decide to SLI or Crossfire down the line.

I have a 26" monitor, and play at 1920x1200. The MSI 6950, GTX 560 phantom and a 6970 cost about the same. I am not too keen on stock coolers, if you know what I mean by that.

 

[thilanliyan]

Has anyone seen such feats? I've been looking for user reviews of 6950's on water, but so far have come up with nothing.

I can hit 1GHz at 1.25v on water. Max is 1.3v in Afterburner....but I'm not sure I wanna push much higher than that. I'm not playing anything that requires more than stock really.

 

[badb0y]

I can hit 1GHz at 1.25v on water. Max is 1.3v in Afterburner....but I'm not sure I wanna push much higher than that. I'm not playing anything that requires more than stock really.

I also hit 1000 core but I think I overshot and used 1.3. Just to make it clear I used the RBE to mod my voltage and don't want to go through all the trouble to move it down a notch.

 

[thilanliyan]

^I don't wanna flash the BIOS because I think some manufacturers will void the warranty if you do. That's also the reason I didn't unlock my 6950, along with not needing the minimal gain from the shaders.

 

[badb0y]

^I don't wanna flash the BIOS because I think some manufacturers will void the warranty if you do. That's also the reason I didn't unlock my 6950, along with not needing the minimal gain from the shaders.

Lol I am unlocked and overvolted like a boss

Whats your max temp on water cooling? My max thus far has been 56 Celsius on my Shaman.

 

[Aikouka]

I tried flashing the 6970 BIOS onto the 6950, but it's pretty damned unstable, which isn't terribly surprising. I had a few driver crashes as well as much higher thermals... I'm talking 72C (6950) vs 85C ("6970"). I eventually dropped the GPU clock down to 840 (halfway between the 6950 and 6970 clocks), but the memory was stuck at the inflated rate.

The ATi drivers are still kind of buggy though. I'm noticing some pretty consistent problems in WoW where the game starts to "bog down" after awhile. As an example, when I use an AoE (multi-target) move, the game will freeze for a small period of time... the more things that are hit, the longer it freezes. I hit about 20 mobs with one move and the game froze for around 3 seconds :\.

Chances are I should be OC'ing my processor if anything... I at least have a good aftermarket cooler on that .

 

[cusideabelincoln]

The shader difference between 6950 vs 6970 is 2 SIMDs as in 5850 vs 5870 but with the Vec-4 is only 2 x 64 = 128 shaders vs 2 x 80 = 160 shaders in Vec-5, so at the same clocks 6950 should be close to 95-97% of the 6970, same as 5850 vs 5870.

Their 6950 has a 380 MHz memory speed advantage. That's 188 vs 176 GBps - a 7% advantage in memory bandwidth. Meanwhile the 6970 should have roughly a (theoretical?) 10% advantage in procesing power, comparing 880 vs 870 MHz. The memory bandwidth could help make up for the lower processing power - plus the fact many things, like ROPs and tessellation engine, are the same between the chips. Most tests show the 6950 OC just a hair behind the 6970, so it doesn't seem too out of place. Actually I think there is a trend: The 6950 appears to catch up (and in a few titles beat) the 6970 as the resolution increases. At lower resolutions the 6970 is faster. So it appears a higher resolution is more stringent on the memory bandwidth - a pretty common fact.

 

[thilanliyan]

Lol I am unlocked and overvolted like a boss

Whats your max temp on water cooling? My max thus far has been 56 Celsius on my Shaman.

I've only really gamed a lot on 1.2v at 950MHz and that gets up to about 50C. That is also with my CPU in the same loop and a cramped case and low speed fans. I care more about silence than ultimate performance so those temps are fine for me.

 

[-Slacker-]

I am a ATI guy and have been for years,

So for your first post you dug up an old ati thread discussing a negative issue with the cards, to advertize products from the opposite camp.

Why don't I believe you?

 

[Dracolich1970]

So for your first post you dug up an old ati thread discussing a negative issue with the cards, to advertize products from the opposite camp.

Why don't I believe you?

Not that I care about what you believe or not, but lack of reading comprehension, I can't let go by.

I am still not sure what card to choose. Two of the cards in the pool are Ati, as mentioned.

 

[brencat]

I've only really gamed a lot on 1.2v at 950MHz and that gets up to about 50C. That is also with my CPU in the same loop and a cramped case and low speed fans. I care more about silence than ultimate performance so those temps are fine for me.

thilan, I've noticed in other threads you did not flash the bios on your 6950. I have a 2gb HIS 6950 on the way and I'm torn about whether to unlock the shaders. I am definitely NOT flashing the 6970 bios onto it though.

I'd like to up the core speed but I've read in other threads about the card being limited to ~ 840 core / 1325 mem. How did you get yours to 900+ and around that limit? Note I will only be using 1 monitor @ 1920 x 1200 native.

Thx.

 

[Elfear]

thilan, I've noticed in other threads you did not flash the bios on your 6950. I have a 2gb HIS 6950 on the way and I'm torn about whether to unlock the shaders. I am definitely NOT flashing the 6970 bios onto it though.

I'd like to up the core speed but I've read in other threads about the card being limited to ~ 840 core / 1325 mem. How did you get yours to 900+ and around that limit? Note I will only be using 1 monitor @ 1920 x 1200 native.

Thx.

MSI Afterburner I'd guess. Unlocks voltage and clocks and has pretty good hardware monitoring.

 

[brencat]

MSI Afterburner I'd guess. Unlocks voltage and clocks and has pretty good hardware monitoring.

Yes, I'd like to use Afterburner if possible -- I think I have to edit the config file to enable unofficial overclocking to go past the 840mhz core limit. But I was still under the impression that the card's voltage is locked down from increases.

If I'm mistaken, please tell me the tools I will need to pass 840 core /1325 mem. I'm even willing to leave the mem at 1325...but would certainly like to try 880 or higher on the core.

Sorry, been an nvidia guy for over 5 years.

 

[thilanliyan]

thilan, I've noticed in other threads you did not flash the bios on your 6950. I have a 2gb HIS 6950 on the way and I'm torn about whether to unlock the shaders. I am definitely NOT flashing the 6970 bios onto it though.

I'd like to up the core speed but I've read in other threads about the card being limited to ~ 840 core / 1325 mem. How did you get yours to 900+ and around that limit? Note I will only be using 1 monitor @ 1920 x 1200 native.

Thx.

Take a look at this:
http://www.overclock.net/ati/909086-6950-shaders-unlocked-vs-full-unlocked.html

Unlocking the shaders does not give you a whole lot of performance. What I will probably do is somewhere down the line (if I keep this card for a while) maybe in a year I will unlock the shaders but right now I don't need to. Maybe by then there will be a bigger performance difference between the 6950 and 6970 at the same clocks, in which case it would be beneficial to unlock it.

I use Afterburner for OCing and that is how you get voltage control and around the 840MHz limit. Voltage control was unlocked from the start for me but I think that is because I had the stock BIOS on my card. If you flash the card I think there is a workaround you have to do.