7970 CF vs 7950 CF (A clock for clock comparison)

LtMatt · 8 Apr 2013 at 18:12

Rusty0611 said:
LOL yes the average of what they top out at just not the highest possible nor the average of what they do on stock volts or with a small adjustments or whatever sorcery they do in reviews these days .

Agree to disagree?

Rusty0611 · 8 Apr 2013 at 18:14

Fine by me, partner.

LtMatt · 8 Apr 2013 at 18:15

Might as well try and save the thread.

Tonester0011 · 9 Apr 2013 at 13:59

Average 7970 overclock: http://hwbot.org/hardware/videocard/radeon_hd_7970/
Average 7950 overclock: http://hwbot.org/hardware/videocard/radeon_hd_7950/

1210/1714 - 7970
1142/1648 - 7950

I'll gladly do some benches using the average clocks using a single 7970 and seeing the difference against an average clock of the 7950.

Those clocks do seem low for the 7950 though.

Rusty0611 · 9 Apr 2013 at 14:01

Yeah I thought about using HWBOT but the amount of users pushing the card to the limit on the 7970 is by definition going to be far higher as users stick this under exotic cooling.

Tonester0011 · 9 Apr 2013 at 14:11

Rusty0611 said:
Yeah I thought about using HWBOT but the amount of users pushing the card to the limit on the 7970 is by definition going to be far higher as users stick this under exotic cooling.

Seperate tables for water, air, cascade and LN2

The sample size is 10x smaller for the 7950s, that shouldn't matter too much as its an average. The average does seem low though!

The highest clocking 7950 is 1330/1746...using LN2!
We've had someone clock to over 1300 on air on this forum lol (yours did 1300 didn't it?)

http://hwbot.org/submission/2342315_dblooi_3dmark11___performance_radeon_hd_7950_14386_marks

TheRealDeal · 9 Apr 2013 at 14:13

Rusty0611 said:
Yeah I thought about using HWBOT but the amount of users pushing the card to the limit on the 7970 is by definition going to be far higher as users stick this under exotic cooling.

I would have thought most people on hwbot were pretty serious about there overclocking thus pushing out what they can from there cards. From the start of the 7 series release it was always claimed by many that the 7970 would clock higher on average compared to the 7950 and from all that i have seen it does appear that you have a better chance to clock higher on a 7970. It may not be factually proven but i have seen more results to prove it than to disprove it.

LtMatt · 9 Apr 2013 at 14:14

Well isn't that surprise? No not really.

Thanks for the links though Ton. :cool:

TheRealDeal · 9 Apr 2013 at 14:14

Tonester0011 said:
Seperate tables for water, air, cascade and LN2

The sample size is 10x smaller for the 7950s, that shouldn't matter too much as its an average. The average does seem low though!

The highest clocking 7950 is 1330/1746...using LN2!
We've had someone clock to over 1300 on air on this forum lol (yours did 1300 didn't it?)

http://hwbot.org/submission/2342315_dblooi_3dmark11___performance_radeon_hd_7950_14386_marks

Could this be down to not having the voltage on tap to push any further.

Tonester0011 · 9 Apr 2013 at 14:17

TheRealDeal said:
Could this be down to not having the voltage on tap to push any further.

Must be, 1300mv seems to be the limit.
That would explain why the average clocks using exotic cooling is so small in comparison to the 70s and why so few submissions with the 50s.

Rusty0611 · 9 Apr 2013 at 14:25

Tonester0011 said:
Seperate tables for water, air, cascade and LN2

The sample size is 10x smaller for the 7950s, that shouldn't matter too much as its an average. The average does seem low though!

The highest clocking 7950 is 1330/1746...using LN2!
We've had someone clock to over 1300 on air on this forum lol (yours did 1300 didn't it?)

http://hwbot.org/submission/2342315_dblooi_3dmark11___performance_radeon_hd_7950_14386_marks

Mmm. I remember discussing the sample before on the forum. The sample is 10x smaller as you say so not really satisfactory to take as ultimate proof.

Yeah I had a 1300/1750 on air (max I achieved). That was with 1.25V pumped through but the dodgy cooler prevented me from trying more. I was nearing 95c with that

.

TheRealDeal said:
I would have thought most people on hwbot were pretty serious about there overclocking thus pushing out what they can from there cards. From the start of the 7 series release it was always claimed by many that the 7970 would clock higher on average compared to the 7950 and from all that i have seen it does appear that you have a better chance to clock higher on a 7970. It may not be factually proven but i have seen more results to prove it than to disprove it.

No that's your own take on the matter. It's always been the case on here that they roughly top out at the same point just recently now the clock for clock difference has been quantified there's been some purchase justification wheeled out when really the enthusiast doesn't need to justify one's purchase... they got the best card.

LtMatt said:
Well isn't that surprise? No not really.

Thanks for the links though Ton.

As above, with one sample so small compared to one so large you can't draw any meaningful conclusion. If you're going to draw conclusions, you need sample sizes the same otherwise the conclusions aren't acceptable.

TheRealDeal · 9 Apr 2013 at 14:30

Rusty0611 said:
Mmm. I remember discussing the sample before on the forum. The sample is 10x smaller as you say so not really satisfactory to take as ultimate proof.

Yeah I had a 1300/1750 on air (max I achieved). That was with 1.25V pumped through but the dodgy cooler prevented me from trying more. I was nearing 95c with that .

No that's your own take on the matter. It's always been the case on here that they roughly top out at the same point just recently now the clock for clock difference has been quantified there's been some purchase justification wheeled out when really the enthusiast doesn't need to justify one's purchase... they got the best card.

As above, with one sample so small compared to one so large you can't draw any meaningful conclusion. If you're going to draw conclusions, you need sample sizes the same otherwise the conclusions aren't acceptable.

Its not my take on it at all. I have never used either card so i have no take on it. I do read a lot though and there are many who say this. It was banded about a lot especially at release and soon after.

tommybhoy · 9 Apr 2013 at 14:32

TheRealDeal said:
From the start of the 7 series release it was always claimed by many that the 7970 would clock higher on average compared to the 7950 and from all that i have seen it does appear that you have a better chance to clock higher on a 7970. It may not be factually proven but i have seen more results to prove it than to disprove it.

+1

Given the amount of both I've had(7), the 7970 keeps going where the 50's top out especially the vram.

Rusty0611 · 9 Apr 2013 at 14:37

TheRealDeal said:
Its not my take on it at all. I have never used either card so i have no take on it. I do read a lot though and there are many who say this. It was banded about a lot especially at release and soon after.

LOL well of course it is your take on it because as you say there is no proof either way...

The problem with using HWBOT as a representative average is:

a) sample sizes
b) the average overclock on air for the 7950 is quite low and then shoots up on water when in fact at 1142 MHz you're nowhere near being temperature limited anyway so why would moving to water suddenly increase your average overclock

Ah, I hear you say, people put the better chips under water and push... I agree but again, without the number of samples increased to smooth out the averages, we're guessing by using these results.

Anyway, waffling slightly the basic answer is the sample sizes are vastly different so you can't use this as definitive.

ICDP · 9 Apr 2013 at 14:41

tommybhoy said:
+1

Given the amount of both I've had(7), the 7970 keeps going where the 50's top out especially the vram.

Strangely my experience differs in that out of 6x 7970s and 3x 7950s I have tested the best overclocker was a 7950 that did 1230/1700. On average 7970s and 7950s have all overclocked to around 1170/1600. I have never had a 7970 that would go beyond 1200 core stable for gaming and that includes a Matrix Platinum.

My own testing shows no perference for the 7970 to have better OC potential than a 7950.

TheRealDeal · 9 Apr 2013 at 14:42

Rusty0611 said:
LOL well of course it is your take on it because as you say there is no proof either way...

The problem with using HWBOT as a representative average is:

a) sample sizes
b) the average overclock on air for the 7950 is quite low and then shoots up on water when in fact at 1142 MHz you're nowhere near being temperature limited anyway so why would moving to water suddenly increase your average overclock

Ah, I hear you say, people put the better chips under water and push... I agree but again, without the number of samples increased to smooth out the averages, we're guessing by using these results.

Anyway, waffling slightly the basic answer is the sample sizes are vastly different so you can't use this as definitive.

It might be a smaller sample size on the 7950 but its still a good amount of 7950's and with a bigger sample size the average oc could go down not up. Is the sample size big enough, i can't answer that but it supports whats already been said since release. From all the reading i have done there are many more people reaching over 1300mhz on a 7970 than there is on 7950's. Has there been more 7970's sold than 7950's? which i doubt is the case. I have seen some people with 7950's over 1300mhz but its been very rare compared to the amount of 7970's even on this forum.

Rusty0611 · 9 Apr 2013 at 14:44

ICDP said:
Strangely my experience differs in that out of 6x 7970s and 3x 7950s I have tested the best overclocker was a 7950 that did 1230/1700. On average 7970s and 7950s have all overclocked to around 1170/1600. I have never had a 7970 that would go beyond 1200 core stable for gaming and that includes a Matrix Platinum.

My own testing shows no perference for the 7970 to have better OC potential than a 7950.

You can find a lot of similar people having experienced the same. And you can also find a lot of people having experienced the opposite.

Personally I think it just isn't right to say definitively that the 7970 clocks further than the 7950 based on anecdotal evidence and therefore should be factored into the decision of purchasing.

TheRealDeal said:
It might be a smaller sample size on the 7950 but its still a good amount of 7950's and with a bigger sample size the average oc could go down not up. Is the sample size big enough, i can't answer that but it supports whats already been said since release. From all the reading i have done there are many more people reaching over 1300mhz on a 7970 than there is on 7950's. Has there been more 7970's sold than 7950's? which i doubt is the case. I have seen some people with 7950's over 1300mhz but its been very rare compared to the amount of 7970's even on this forum.

It doesn't matter if you've got a "good" amount of 7950s, the size of the sample is vastly different therefore....

What's been said since release is just anecdotal evidence and if we're talking in the realms of chance/probability of overclocking to x clock speed it doesn't hold any weight. As is the rest of what you're saying.

TheRealDeal · 9 Apr 2013 at 14:55

Rusty0611 said:
You can find a lot of similar people having experienced the same. And you can also find a lot of people having experienced the opposite.

Personally I think it just isn't right to say definitively that the 7970 clocks further than the 7950 based on anecdotal evidence and therefore should be factored into the decision of purchasing.

It doesn't matter if you've got a "good" amount of 7950s, the size of the sample is vastly different therefore....

What's been said since release is just anecdotal evidence and if we're talking in the realms of chance/probability of overclocking to x clock speed it doesn't hold any weight.

There is more evidence in support of the 7970 clocking better compared to the 7950. We can never prove this 100% but even you have to admit theres more evidence in support than there is against. I myself love facts but sometimes you just have to look at the evidence in hand and make an informed decision.

ICDP · 9 Apr 2013 at 15:00

Rusty0611 said:
You can find a lot of similar people having experienced the same. And you can also find a lot of people having experienced the opposite.

Personally I think it just isn't right to say definitively that the 7970 clocks further than the 7950 based on anecdotal evidence and therefore should be factored into the decision of purchasing.

It doesn't matter if you've got a "good" amount of 7950s, the size of the sample is vastly different therefore....

What's been said since release is just anecdotal evidence and if we're talking in the realms of chance/probability of overclocking to x clock speed it doesn't hold any weight. As is the rest of what you're saying.

I think you just replied without reading. :confused:

My post basically states that I feel based on my own experience, it is a myth that a 7970 core will overclock higher than a 7950 core.

Rusty0611 · 9 Apr 2013 at 15:03

TheRealDeal said:
There is more evidence in support of the 7970 clocking better compared to the 7950. We can never prove this 100% but even you have to admit theres more evidence in support than there is against. I myself love facts but sometimes you just have to look at the evidence in hand and make an informed decision.

If by evidence you mean stories of what people have achieved then, yes, there's more. But what about all the people who haven't posted what clocks they've got, either way... what about people like me who had good 7950s (3 out of 4) and didn't post them on HWBOT?

My point is not that the people who say that the 7970 overclocks further than the 7950 are necessarily wrong... it's more that the evidence people are using to back up this claim is purely anecdotal and any technical reasonings put forward does not satisfy the hypothesis :cool:

.

You can spend more on a 7970, get ~5% more performance clock for clock, and hope that you get a decent clocker. Or you can get a 7950, get ~5% less performance clock for clock and hope you get a decent clocker. Hoping for a decent clocker is common throughout and then if you move from that and start saying: "well your chances of getting a good clocker with a 7970 is higher".... you'll get people like me saying, OK, where's your statistical analysis?

Where I think you do have a higher chance of overclocking further would be with the Lightnings/Matrix Plats...

ICDP said:
I think you just replied without reading.

My post basically states that I feel based on my own experience, it is a myth that a 7970 core will overclock higher than a 7950 core.

No I think that is you friend. I was agreeing with you.