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

[LtMatt]

Oh yeah we can't be accurate to the dot (don't think anyone or me has actually said this) but what we can do is do all we can to minimise chances for differences. I don't think anybody is even saying, "5% end". What is being said is that the 5% figure looks to be more accurate than the 10% figure based on actual evidence.

What I will say is that I haven't seen an actual gap of anything close to 10% (discounting Metro as the benchmark is dodgy) but that I still have an open mind if anybody has a game to benchmark to test. Not to say it wasn't 10% back in the day (or even 15-20%) but that's not relevant in today's terms in the same way we don't use 14 month old comparisons of the 7950/7970 against the 670/680.

Tommy's argument fails because it assumes that for that review to still hold true today (which is what he's saying), driver improvements across the 7000 series of cards have produced universal increases in performance across the range which we know is not true.

As we're talking such small differences the problem with a non standard benchmark (e.g. BF3) is that it can open up a difference that isn't there or close up a difference which is actually there.

At clock for clock the difference is generally going to be around 5% which certain examples lower and higher than that. 10% is looking unlikely ill agree at the moment.

Going off topic slightly but one thing to consider i think when recommending a 7950 over a 7970 to someone is that generally the 7970 will overclock further. The core maybe only slightly more (not to mention most 7950's have 7950's pcb's not 7970 pcb's which will oc better) but the memory will go considerably higher on the 7970 as it uses higher spec memory. This point should always be noted in my opinion as you can add a good amount more performance by increasing the bandwidth. I would speculate a guess at 5-10%. I don't have figures to back this up, but this is maybe something i can get my teeth into at some point and actually do some real world testing of the difference between 1375 and 1875 memory speed. Its all fine and well to say if you buy a 7950 you'll get within 5% of the 7970 and you will providing you can clock match but that is not often possible, unless you clock your 7970 conservatively.

 

[Diagro]

At clock for clock the difference is generally going to be around 5% which certain examples lower and higher than that. 10% is looking unlikely ill agree at the moment.

Going off topic slightly but one thing to consider i think when recommending a 7950 over a 7970 to someone is that generally the 7970 will overclock further. The core maybe only slightly more (not to mention most 7950's have 7950's pcb's not 7970 pcb's which will oc better) but the memory will go considerably higher on the 7970 as it uses higher spec memory. This point should always be noted in my opinion as you can add a good amount more performance by increasing the bandwidth. I would speculate a guess at 5-10%. I don't have figures to back this up, but this is maybe something i can get my teeth into at some point. Its all fine and well to say if you buy a 7950 you'll get within 5% of the 7970 and you will providing you can clock match but that is not often possible.

+1

thew 7970 will most of the time overclock much more.. Increasing the Gap

 

[Rusty0611]

Well I've yet to see one more than 1% higher than 5%!

A good 7950 goes the same kind of distance as a good 7970. The key word here is 'good' because a stinking 7970 is just as bad as a stinking 7950 (Tonester's second card). My good 7950 which I sent back due to the MSI problem did 1300/1750 but was limited by temperatures. If I took the cooler off and stuck an Accelero on it I'm sure I'd be around your clock speeds. My current Gigabyte one does 1275/1700 on 13.1 drivers.... At the end of the day, the silicon lottery overrides any debate as to which will overclock further and while connected, it is a touch tangential to a clock for clock comparison.

A 7950 PCB does indeed have worse memory chips, but we're talking the difference between ~1600 MHz and ~1800 MHz which isn't much in performance terms in games. Highlighted games because I've seen myself that a memory OC scales quite nicely in benchmarks.

thew 7970 will most of the time overclock much more.. Increasing the Gap

This is a clock for clock comparison thread but you haven't provided any proof that that is the case anyway.

Can give you the UD5H? Lol.
I'll be on X79 hopefully by the end of this week so 1155 spare till I sell (sold the CPU)

I'll still have to sit through the BIOS recovery screen, plug in the hard drive. update BIOS, restore settings as soon as I unplug a 7950 . I've done it so many times from when I was faffing around with the 680s and 7950s together that the pain of it is too much to bear.

 

[LtMatt]

Well I've yet to see one more than 1% higher than 5%!

A good 7950 goes the same kind of distance as a good 7970. The key word here is 'good' because a stinking 7970 is just as bad as a stinking 7950 (Tonester's second card). My good 7950 which I sent back due to the MSI problem did 1300/1750 but was limited by temperatures. If I took the cooler off and stuck an Accelero on it I'm sure I'd be around your clock speeds. My current Gigabyte one does 1275/1700 on 13.1 drivers.... At the end of the day, the silicon lottery overrides any debate as to which will overclock further and while connected, it is a touch tangential to a clock for clock comparison.

Yes you will get some 7950's that can match, the majority won't be able to for the reasons i've already mentioned. You will get more good 7970's than 7950's. A cooler running temp won't help memory speeds either, only core.

 

[Rusty0611]

Yes you will get some 7950's that can match, the majority won't be able to for the reasons i've already mentioned. You will get more good 7970's than 7950's. A cooler running temp won't help memory speeds either, only core.

People say this but without any evidence to hand. I know there isn't anything. It's become common knowledge without ever being proven. A selective forum sample isn't evidence either.

I've had 4 7950s - 2 were temperature limited at 1250 & 1300/1750 by the dodgy MSI cooler, 1 does 1275/1700, the other does 1200/1650. My point is not that it means all 7950s will fall within this range, it's pointing out it's just impossible to make general statements like that without a large sample of evidence.

p.s. that was just the max clock speeds I ran.... zero memory artifacts but I didn't go further because I didn't have time to test for stability as they both went back to OcUK. I saw nothing to suggest that they wouldn't have gone another 50-100 MHz. Also let's be honest, your 7970 is far from the norm as well .

The point is all this talk of "majority" and "most" is without any kind of statistical analysis. I'm not expecting you to go away and do it p) I'm basically saying it's not a proven fact and there's no evidence to suggest that is the case. What I agree on is that generally the 7970 memory will do another 200 MHz or so compared to vanilla 7950 models. What I disagree on is that this makes enough difference in performance to realistically consider a 7970 over a 7950.

 

[tommybhoy]

I have used 5 7950's and 2 7970's and the 50's don't come close to the vram clocks the 70 can achieve for the reasons outlined above-they have better chips on the vram in general, of course it's still down to the lottery but the 70's vram carries on when the 50's hits a brick wall and it can make the difference in high AA scenarios like BF3.

lol you said my results were invalid on something else just because they were from Autumn 2012 or whevever, now a 14 month comparison holds true today because Tommybhoy says so. Logic failure. I didn't take into account your results because what do you want me to do with them? You were 40% slower than Matt's 7970 at the same clock speed in Tomb Raider which can't purely be down to PCI 3.0 8x.

Don't take my words and use them out of context to suit a different discussion Rusty, poor very poor indeed:

Your findings last August or so=outdated and were from the best you could get to challenge the 2Gb limit=BF3, but this is the middle of March and like I said then and I'm saying now, it wasn't enough.

BF3 has been surpassed by vram requirements

I already said earlier-with your results you posted above, the most demanding title is BF3, that has been superseded in regards to vram.

The only term implied talking about your results being outdated were in relation to a vram/bus discussion.

Since this discussion is entirely different-performance difference across the board, older titles are valid, hence the point about performance gains through newer drivers possibly being static in non important titles.

So don't mince my words for effect/leverage, call it what you like.

Well when you're trying to nit pick and basically save face over the 5/10% debate (for reasons I won't pretend to understand) then yes, it is just you. These results are just... as they are for today's games on today's drivers. The difference may have been more/less back in February 2012 (lmao) but that is just irrelevant now.

The point is you're basing off an old article which doesn't represent today's performance due to driver changes. I'm not saying performance boosts are one way (you don't really think that do you?), I'm just saying it isn't representative of today's differences. You can't pick and choose old articles as and when you please and discount "old" analysis the next.

There's no nitpicking/face saving(obviously your looking along those lines though) but stating that driver improvements are on a game by game basis unless AMD release driver notes stating along the lines of-10-20% driver improvement across the whole board of titles supported in their drivers.

There was an issue somewhere with Matt's/my comparison that's why it was removed quickly, my CrossFire results don't have any x8 problems for comparison.

But in future please don't misquote me as it tends to put users down the wrong track as what happened in another thread that the quote was taken out of context again LEAVING FALSE ACCUSATIONS aimed at myself.

 

[LtMatt]

People say this but without any evidence to hand. I know there isn't anything. It's become common knowledge without ever being proven. A selective forum sample isn't evidence either.

I've had 4 7950s - 2 were temperature limited at 1250 & 1300/1750 by the dodgy MSI cooler, 1 does 1275/1700, the other does 1200/1650. My point is not that it doesn't mean all 7950s will fall within this range, it's pointing out it's just impossible to make general statements like that without a large sample of evidence.

p.s. that was just the max clock speeds I ran.... zero memory artifacts but I didn't go further because I didn't have time to test for stability as they both went back to OcUK. I saw nothing to suggest that they wouldn't have gone another 50-100 MHz. Also let's be honest, your 7970 is far from the norm as well .

The point is all this talk of "majority" and "most" is without any kind of statistical analysis. I'm not expecting you to go away and do it p) I'm basically saying it's not a proven fact and there's no evidence to suggest that is the case. What I agree on is that generally the 7970 memory will do another 200 MHz or so compared to vanilla 7950 models. What I disagree on is that this makes enough difference in performance to realistically consider a 7970 over a 7950.

You have to consider that the 7970's have a better pcb which aids overclocking. 7970's are able to deliver more power as most 7950's only have 2x6 pin power connections where as all 7970 have 8+6 pin. The 7970 also has extra shaders, compute units and the higher clocking memory. The 7970 will also have a higher TDP limit as well which will definitely be a factor when large overclocks are applied. You trigger the OCP limit, your card shuts off and is dead until you restart. It will take some effort to trigger the limt but it is possible ive done it myself and if my limit was 50-75 Watt less than it is now id trigger it a lot easier. Its probably also safe to assume that in percentage terms the 7970 will clock higher on the core as its stock clocks are higher.

How much of a difference this all makes is indeed a great debate and one neither of us can really answer. But i think these are things to be considered in light of saying get a 7950 as its only a few percent slower than a 7970. Then again people probably don't think or get anal about all those points like me but hey im thorough.

 

[Tonester0011]

You have to consider that the 7970's have a better pcb which aids overclocking. 7970's are able to deliver more power as most 7950's only have 2x6 pin power connections where as all 7970 have 8+6 pin. The 7970 also has extra shaders, compute units and the higher clocking memory. The 7970 will also have a higher TDP limit as well which will definitely be a factor when large overclocks are applied. You trigger the OCP limit, your card shuts off and is dead until you restart. It will take some effort to trigger the limt but it is possible ive done it myself and if my limit was 50-75 Watt less than it is now id trigger it a lot easier. Its probably also safe to assume that in percentage terms the 7970 will clock higher on the core as its stock clocks are higher.

How much of a difference this all makes is indeed a great debate and one neither of us can really answer. But i think these are things to be considered in light of saying get a 7950 as its only a few percent slower than a 7950.

I've never reached the TDP limit, i've thrown 1381mv through the card...memory voltage as well. Before my second card died both at the same time

 

[LtMatt]

I've never reached the TDP limit, i've thrown 1381mv through the card...memory voltage as well. Before my second card died both at the same time

Its possible and not something you really want to be doing. Powertune will try and protect your card by down clocking but if you push it hard enough and get 300 Watt or higher then its possible. The limit might well be higher than that.

Also quite possible your card dies shortly after as you found out.

Sill voltage will add to the TDP of course but it all depends on the clocks and fps you're producing. Massive overclocks without a fps limit on a demanding benchmark producing silly high fps is a sure fire way to get there. Keeping the card cool also keep the TDP down.

I think the TDP for a 7970 is 250W and a 7950 is, 200W maybe. Power tune will allow you an extra 20% TDP on each card.

EDIT

Powertune is hardcoded into either the drivers or the card, im not sure which. There is no way to get around it as far as i know.

 

[Rusty0611]

I have used 5 7950's and 2 7970's and the 50's don't come close to the vram clocks the 70 can achieve for the reasons outlined above-they have better chips on the vram in general, of course it's still down to the lottery but the 70's vram carries on when the 50's hits a brick wall and it can make the difference in high AA scenarios like BF3.

I don't believe the extra amount the 7970s clock to on the memory really account for much game performance.

Don't take my words and use them out of context to suit a different discussion Rusty, poor very poor indeed:

If you say so. But that IS what you said. Keep on twisting.

The only term implied talking about your results being outdated were in relation to a vram/bus discussion.

Since this discussion is entirely different-performance difference across the board, older titles are valid, hence the point about performance gains through newer drivers possibly being static in non important titles.

So don't mince my words for effect/leverage, call it what you like.

As I said, when it suits....

There's no nitpicking/face saving(obviously your looking along those lines though) but stating that driver improvements are on a game by game basis unless AMD release driver notes stating along the lines of-10-20% driver improvement across the whole board of titles supported in their drivers.

"Tommy's argument fails because it assumes that for that review to still hold true today (which is what he's saying), driver improvements across the 7000 series of cards have produced universal increases in performance across the range which we know is not true."

There was an issue somewhere with Matt's/my comparison that's why it was removed quickly, my CrossFire results don't have any x8 problems for comparison.

But in future please don't misquote me as it tends to put users down the wrong track as what happened in another thread that the quote was taken out of context again LEAVING FALSE ACCUSATIONS aimed at myself.

False accusations?!

I'm not going to tarnish the thread anymore because it's been turned south enough, yet again by the nitpicking, doubling back, twisting, turning..... so as the OP, I ask unless you've got anything to contribute to the topic at hand (clock vs clock 7950/7970 comparisons) please exit the thread. Nobody reading this has got any interest in it and to be honest, neither have I. What's been said has been said but anything more and I'll RTM or ask a mod to remove it to keep the thread on track. Thanks for your understanding.

You have to consider that the 7970's have a better pcb which aids overclocking. 7970's are able to deliver more power as most 7950's only have 2x6 pin power connections where as all 7970 have 8+6 pin. The 7970 also has extra shaders, compute units and the higher clocking memory. The 7970 will also have a higher TDP limit as well which will definitely be a factor when large overclocks are applied. You trigger the OCP limit, your card shuts off and is dead until you restart. It will take some effort to trigger the limt but it is possible ive done it myself and if my limit was 50-75 Watt less than it is now id trigger it a lot easier. How much of a difference this all makes is indeed a great debate and one neither of us can really answer. But i think these are things to be considered in light of saying get a 7950 as its only a few percent slower than a 7970. Then again people probably don't think or get anal about all those points like me but hey im thorough.

All well and good Matt, but how does that relate to what a card can really achieve at maximum in reality. I get the theory but silicon lottery still overrides all of those points to an extent.

Its probably also safe to assume that in percentage terms the 7970 will clock higher on the core as its stock clocks are higher.

Nope. I know what you're getting at but in reality I don't think it's true nor can I think of any technical reason as to why that would be the case.

 

[LtMatt]

All well and good Matt, but how does that relate to what a card can really achieve at maximum in reality. I get the theory but silicon lottery still overrides all of those points to an extent.

I'd rather buy a silicone lottery ticket from the 7970 pool than the 7950 pool. Wouldn't you?

It still comes down to a lottery but lets just say your odds go up a bit for the reasons mentioned. Otherwise we'd see more 7950's above 7970's in the benchmark threads/game benchmarks. As it stands there are very few.

My point is that all these factors add up to more performance which in my opinion is another point to be considered.

Clock for clock the difference is not that big. But these other factors can add to that difference and that is what never gets mentioned or talked about. Its just too easily assumed that the 7950 is 5% or less slower and there are no other advantages to owning a 7970 over a 7950.

Nope. I know what you're getting at but in reality I don't think it's true nor can I think of any technical reason as to why that would be the case.

I don't know any technical reason either. I've a good mind to ask Thracks.

Lets think about this sensibly though if 7950's had better cores than 7970's why are they in 7950's and not 7970's which are AMD's current flag ship cards?

I think they are probably identical but the reasons ive mentioned means that the 7970 core will on average go further than the 7950 core.

 

[Rusty0611]

I'd rather buy a silicone lottery ticket from the 7970 pool than the 7950 pool. Wouldn't you?

It still comes down to a lottery but lets just say your odds go up a bit for the reasons mentioned. Otherwise we'd see more 7950's above 7970's in the benchmark threads/game benchmarks. As it stands there are very few.

Clock for clock the difference is not that big. But these other factors can add to that difference and that is what never gets mentioned or talked about.

The 7950 pool because I've seen no evidence to say that you're more likely to get a good 7970 over a good 7950 and we can see the clock for clock difference sits on or below 5% and they're cheaper. If you're comparing custom cooled vs custom cooled quite a difference as well in price. Not to say my way is the only way of looking at it but that is my POV.

My point is that all these factors add up to more performance which in my opinion is another point to be considered.

No they add up for the potential for more performance which is not the same as what you're saying. The things you've said don't automatically mean more performance.

I don't know any technical reason either. I've a good mind to ask Thracks.

Lets think about this sensibly though if 7950's had better cores than 7970's why are they in 7950's and not 7970's which are AMD's current flag ship cards?

I think they are probably identical but the reasons ive mentioned means that the 7970 core will on average go further than the 7950 core.

Impossible to answer without knowing what their internal benchmarking is for whether it becomes a 7950 or 7970. Still not seeing any evidence to suggest that the 7970s go further on a representative sample .

Edit: to clarify my position, I'm not saying that what you're saying is necessarily incorrect, I'm just keeping an open mind as I haven't seen anything comprehensive enough to really believe it.

 

[LtMatt]

The 7950 pool because I've seen no evidence to say that you're more likely to get a good 7970 over a good 7950 and we can see the clock for clock difference sits on or below 5% and they're cheaper. If you're comparing custom cooled vs custom cooled quite a difference as well in price. Not to say my way is the only way of looking at it but that is my POV.

This is a lottery though, price doesn't come into it. Clock for clock difference is 5% for arguments sake. The majority of 7950's will not match 7970 at maximum overclocks. If this was the case we'd see more of it here in the many game and benchmark threads.

How does the evidence that the 7970 has faster memory not come into it your decision on which one to get?

How many 7970's reach 1300 core? Not loads but quite a few here. How many 7950's reach 1300 core? Much less. There's something in that. Assuming the cores are identical those other factors that you dismiss obviously do make a difference.

No they add up for the potential for more performance which is not the same as what you're saying. The things you've said don't automatically mean more performance.

They are factors to be considered though and the faster memory will mean more performance as will the extra shaders and compute units. At the same clocks these seem to mean an extra 5%. With the extra clock speeds you will likely get from the core and memory i reckon you could be looking at another 5% maybe more.

 

[Rusty0611]

This is a lottery though, price doesn't come into it. Clock for clock difference is 5% for arguments sake. The majority of 7950's will not match 7970 at maximum overclocks. If this was the case we'd see more of it here in the many game and benchmark threads.

You can't say majority without taking a statistical sample lol. You don't have the evidence to make those claims.

How does the evidence that the 7970 has faster memory not come into it your decision on which one to get?

I don't believe it makes that much difference in performance in games going from your average 7950 memory OC to your average 7970 memory OC.

How many 7970's reach 1300 core? Not loads but quite a few here. How many 7950's reach 1300 core? Much less. There's something in that. Assuming the cores are identical those other factors that you dismiss obviously do make a difference.

They are factors to be considered though and the faster memory will mean more performance as will the extra shaders and compute units. At the same clocks these seem to mean an extra 5%. With the extra clock speeds you will likely get from the core and memory i reckon you could be looking at another 5% maybe more.

Again statistics about more and less without evidence. Can't do that mate.

The rest is all on the assumption that they do clock faster on average. Still not seeing any evidence that they do. Mate you're not going to convince me based on a few samples from here where people have Accelero's and water blocks on them lol. The 7970 is the top end card and as such is likely to net the enthusiasts who benchmark more and push the cards more.

You're also mixing up maximum clocks a card can achieve and average clocks. I have no doubt what will top out higher of the two but I thought we were talking averages and now we're talking selective samples based on golden cards .

If we take a pretty decent overclock of 1250 on the core then what proportion of 7970s can do that speed vs what proportion of 7950s (voltage unlocked models)? I don't know but from my own mini sample I didn't see anything to change my mind that your chances of getting a card which can be pushed to this level is quite high with the 7950s. I don't know about the 7970s as I've not owned anyway but I don't see any reason for it be higher and I've seen no proof that is the case.

Also if we're talking games, then I struggle to believe that many people run their 7900 series cards at 1300+ 24/7 .

 

[LtMatt]

You can't say majority without taking a statistical sample lol. You don't have the evidence to make those claims.

The evidence im using is from looking at benchmark reviews of 7970/7950's around the internet when the cards were released and looking at the many game result benchmarks and benchmarks threads in this section and at overclock.net.

7970's just clock higher than 7950's generally and thats what all those results show. I expect 680's will on average clock higher than most 670's as it was just designed to be faster.

If you can show me im wrong please do, but i know you can't so i guess we'll just have to agree to disagree.

I'd rather have a 7970 you'd rather have a 7950, strangely.

 

[Rusty0611]

I get that Matt but how sure are you that a) the cooling set up is the same and b) the competence of the person using the card is the same?

You might be right but you just can't make claims of majority, more and less without a large sample. Having a gander at a few benchies on the net doesn't count.

I paid £230 for my 7950. You've paid, what £300 + £50 for a cooler and yours while gaming performs (including the extra clocks) probably around 7-8% faster. Not worth an extra £120 to me personally but I can see why some would want to. If they were the same price then of course I'd prefer a 7970. But then if everything was the same price I'd want a Titan

 

[LtMatt]

I get that Matt but how sure are you that a) the cooling set up is the same and b) the competence of the person using the card is the same?

You might be right but you just can't make claims of majority, more and less without a large sample. Having a gander at a few benchies on the net doesn't count.

I paid £230 for my 7950. You've paid, what £300 + £50 for a cooler and yours while gaming performs (including the extra clocks) probably around 7-8% faster. Not worth an extra £120 to me personally but I can see why some would want to. If they were the same price then of course I'd prefer a 7970. But then if everything was the same price I'd want a Titan

Cooling setup will vary but it won't on reference cards and that is where all the early official reviews confirm, the 7970 clocks higher on average.

I paid £299 but sold the games so ended paying about £250 from memory. For an extra £20 id take the msi 7970 oc over any 7950 card.

Before i bought the accelero for £40 my card could do 1250/1875 benching and 1225/1823 game stable.

 

[Rusty0611]

Cooling setup will vary but it won't on reference cards and that is where all the early official reviews confirm, the 7970 clocks higher on average.

In reviews they don't push cards to the utter limit.......

 

[LtMatt]

In reviews they don't push cards to the utter limit.......

But we were talking about averages as you reminded me a few posts back.

 

[Rusty0611]

But we were talking about averages as you reminded me a few posts back.

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 .