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

[ICDP]

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.

On release the 7970 had a stock voltage of 1.175v, the 7950 stock voltage was ~1.031-1.091v. So the 7950 would not reach the same clocks due to less headroom with lower stock voltage. It wasn't until we had the ability to increase volts manually that the true potential of 7950 overclocking could be harnessed.

Even now a new 7970 will be generally running higher stock volts than a new 7950. Unless you have both running the same voltages you will find the 7970 overclocks higher and come to an invalid conclussion. The myth that the 7970 overclocks higher was based on this often overlooked fact. Undervolt a 7970 to 1.031v and see how high it clocks.

 

[tommybhoy]

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.

My words are more along the line of vram clocking, it keeps going where the 50's can't cope, they simply can't hit the same vram clocks in general.

The MSI 7970 OC I had keeps going with added voltage on the vram, 50's memory correction starts quicker down the clocks even with extra voltage.

It wasn't just my OC sample, Matt's, Petey's, scotty's iirc, all achieved crazy vram clocks.

It's been said vram clocking doesn't make much difference, but BF3 absolutely loves high vram clocks to name but one title of benefit from vram clocking.

 

[ICDP]

My words are more along the line of vram clocking, it keeps going where the 50's can't cope, they simply can't hit the same vram clocks in general.

The MSI 7970 OC I had keeps going with added voltage on the vram, 50's memory correction starts quicker down the clocks even with extra voltage.

It wasn't just my OC sample, Matt's, Petey's, scotty's iirc, all achieved crazy vram clocks.

It's been said vram clocking doesn't make much difference, but BF3 absolutely loves high vram clocks to name but one title of benefit from vram clocking.

None of that changes the fact that my own experience shows the 7950 reaching higher overclocks on VRAM than any of my 7970s. This does not make my experience a fact, it just shows we shouldn't generalise based on a small sample. Yes the 7970 PCB has better VRAM than a 7950 PCB and "may" reach higher OC but that is not a guarantee and certainly not worth the £100+ premium you pay for a 7970.

 

[Rusty0611]

It's been said vram clocking doesn't make much difference, but BF3 absolutely loves high vram clocks to name but one title of benefit from vram clocking.

I'm going to run a test at 1500/1300 memory clock speeds to see what difference it makes in the same games as benched above later on. Not convinced it makes a massive difference and I've not seen much evidence of games scaling all that brilliantly with a memory overclock.

 

[tommybhoy]

None of that changes the fact that my own experience shows the 7950 reaching higher overclocks on VRAM than any of my 7970s. This does not make my experience a fact, it just shows we shouldn't generalise based on a small sample. Yes the 7970 PCB has better VRAM than a 7950 PCB and "may" reach higher OC but that is not a guarantee and certainly not worth the £100+ premium you pay for a 7970.

No oc is a guarantee, simply stating, imo, from what I've saw, the 70's in general clock higher on the vram, I'm 100% with you though that the 70 isn't worth the premium for playing games.

 

[breadturbo]

Here's a little into the burner then

What do you all make of this 'ASIC quality' business?

Mine both say 66.5% lol, but easily hit 1250 with only 1.2v

 

[tommybhoy]

I rate it, but others don't, give me a low Asic over a high Asic any day of the week.

 

[LtMatt]

Here's a little into the burner then

What do you all make of this 'ASIC quality' business?

Mine both say 66.5% lol, but easily hit 1250 with only 1.2v

Low asic is generally better. It all comes down to the silicon lottery but with low asic you can add more voltage and will run cooler with more voltage added. High asic requires less voltage at stock so may run cooler, but the card won't like lots of extra voltage and will run considerably hotter than a low asic card once you start adding a lot of voltage.

 

[ICDP]

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

Apologies for my idiocy