Gigabyte 7970 or 7950 Xfire

Voicon · 31 Mar 2013 at 17:41

Hi All

I am in the market for a new GFX card, Looking at the Gigabyte Windforce series either the 7970 or 2 X 7950 XFire my only concern with the 7950's is my PSU, on Gigabyte's website it says power requirement of 500W per card is that right?

I have a OCZ Fatal1ty 750W PSU.

Other system components are Gigabyte mobo, intel 3770 with Corsair H80, 16Gb Corsair Vengance, Vertex 4 SSD, 2 X Sata 6Gb 1Tb HDD's and a DVD writer

Monitor resolution is 5760 X 1080.

Cheers

Voicon · 31 Mar 2013 at 17:49

Also as you can see in my sig I do Folding@Home for the OcUK team so they will get a bit of a hammering

andybird123 · 31 Mar 2013 at 17:54

AMD have acknowledged there are big problems with crossfire delivering stutter and low effective FPS at the moment, driver update to improve things is due June / July time... so for now you might be better off with a single card rather than 2 if you have to have AMD cards

7970 and 7950 are on a par really when fully overclocked, either as a single card will mean turning down a lot of settings at that resolution

http://forums.overclockers.co.uk/showthread.php?t=18500294

tribz · 31 Mar 2013 at 18:00

Ive tried a pair of 7950's in CF last week and there's no doubt they were fast cards. Sadly in gaming they just didn't feel as smooth to me as my single 7970 so I've gone back to that for now.

There are plenty of people here though that are running them in CF without any problems so I think its probably suck it and see.

Re the power supply, they drew 500w at the plug whilst benching on my system below.

ICDP · 31 Mar 2013 at 18:23

Stay clear of the Gigabyte cards, they are now locked voltage. If you get 2x 7950s for CF you will be stuck with 2 cards that are 1.25v and will overheat.

I am using 7950s in CF and if I go over 1.1 volts I get excessive heat and that is with a gap between the cards.

Rusty0611 · 31 Mar 2013 at 18:31

ICDP said:
Stay clear of the Gigabyte cards, they are now locked voltage. If you get 2x 7950s for CF you will be stuck with 2 cards that are 1.25v and will overheat.

I am using 7950s in CF and if I go over 1.1 volts I get excessive heat and that is with a gap between the cards.

Poor airflow because I don't...

ICDP · 31 Mar 2013 at 19:45

Rusty0611 said:
Poor airflow because I don't...

I should have qualified that the 2x 7950s are running 1050/1550 1.031v. My case has plenty of airflow and the cards run at ~70c top ~60c bottom with a non-aggressive fan profile. I can get them both running 1175 with a more aggressive fan profile and 1.1v - 1.2v but I prefer quiet. If both were Gigabyte WF 7950s locked at 1.25v those temperatures would be much higher and run much louder.

7950s do not need 1.25v to run 1GHz

Rusty0611 · 31 Mar 2013 at 19:51

ICDP said:
I should gave qualified that the 2x 7950s are running 1050/1550 1.031v. My case has plenty of airflow and the cards run at ~70c top ~60c bottom with a non-aggressive fan profile. I can get them both t0 1175 with a more aggressive fan profile and 1.2v but I prefer quiet. If both were Gigabyte WF 7950s locked at 1.25v those temperatures would be much higher and run much louder.

7950s do not need 1.25v to run 1GHz

No you're right they don't but mine run can run at 1200 (my max OC which both cards can do) and I'm only pushing 70-73c. Default fan curve as well.

And my GB is locked to 1.25V.

24/7 clocks neither break 65c.

ICDP · 31 Mar 2013 at 20:06

The point isn't what they can run at using locked volts at 1.25, but that for the same clocks you could potentially use less volts.

tres_kun · 31 Mar 2013 at 20:21

500W power supply if you have one card
If you have a second one you should have 700W so
You are good to go
HD7970 has 190W Max power draw but it depends on card and that is max
Not real power draw

subbytna · 31 Mar 2013 at 20:28

Running two 7950s at stock speeds will eat any game he throws at it. No need to OC two 7950s...Just run them at stock speeds and enjoy your gaming

ICDP · 31 Mar 2013 at 20:48

subbytna said:
Running two 7950s at stock speeds will eat any game he throws at it. No need to OC two 7950s...Just run them at stock speeds and enjoy your gaming

The point isn't about overclocking it is about the simple fact that Gigabyte WF 7950s are now locked at 1.25v which is too high. By all means stay at stock speeds but he may as well get 7950s that are running 1.031v stock than 1.25v stock.

There is less heat to dissipate if the volts are lower. Less heat = cooler and quieter, no matter what core clock they are run at.

Rusty0611 · 31 Mar 2013 at 21:07

ICDP said:
The point isn't what they can run at using locked volts at 1.25, but that for the same clocks you could potentially use less volts.

No the point is more that it doesn't necessarily translate into unacceptable temperatures.

ICDP · 31 Mar 2013 at 21:24

Four Heaven 4.0 runs on a VTX3D 7950 X-Edition - 90% ASIC. 1.256 run done 1st, then 1.175 and finally 1.031. The core and VRAM clocks remained at stock without any overclock.

880/1250 (stock clocks)
Custom
1.031v
70c - 41% fan speed.

1.175v
82c - 60% fan speed.

1.256v
90c - 65% fan speed.
At this setting the card actually started throttling to 501MHz because the card was overheating so much.

Finally I did another Heaven 4.0 run with the following overclock.
1050/1550
Custom
1.031v
74c - 47% fan speed.

So barely any different than at the sock clocks. It is the voltage that makes the largest difference to heat, not the core clock.

Rusty0611 · 31 Mar 2013 at 21:26

Yes and you must have poor airflow then and/or a bad GPU cooler because my temperatues (at 1.25V on both) don't get nowhere near that. I'm not really too interested in debating the nuances of what yours do and what mine do, the point is that a 1.25V high lock doesn't necessarily translate to high temperatures.

ICDP · 31 Mar 2013 at 21:33

Rusty0611 said:
Yes and you must have poor airflow then and/or a bad GPU cooler because my temperatues (at 1.25V on both) don't get nowhere near that. I'm not really too interested in debating the nuances of what yours do and what mine do, the point is that a 1.25V high lock doesn't necessarily translate to high temperatures.

Oh dear, you are now at the point where you are arguing for the sake of it. Anyone who thinks that higher volts, which means more current does not ALWAYS 100% GUARANTEED = HIGHER HEAT is wrong, period. Yet again instead of saying a simple you are correct, it always better to go for a lower voltage card and leaving it at that, you chime in with a "you have poor airflow".

Let me post the point that proves that my airflow is fine once again. "the 2x 7950s are running 1050/1550 1.031v. My case has plenty of airflow and the cards run at ~70c top ~60c bottom with a non-aggressive fan profile".

Rusty0611 · 31 Mar 2013 at 21:36

ICDP said:
Oh dear, you are now at the point where you are arguing for the sake of it. Anyone who thinks that higher volts, which means more current does not ALWAYS 100% GUARANTEED = HIGHER HEAT is wrong, period.

LOL what?

I'm not saying it doesn't equal more heat, I'm saying it doesn't necessarily equal unacceptable temperatures. I'm confused you don't understand.

Look again for you:

Rusty0611 said:
No the point is more that it doesn't necessarily translate into unacceptable temperatures.

ICDP said:
Yet again instead of saying a simple you are correct, it always better to go for a lower voltage card and leaving it at that, you chime in with a "you have poor airflow".

Well you must do if your cards at stock are the same as mine at 1.25V

Voicon · 31 Mar 2013 at 21:42

Thanks all.

I don't think I will overclock if I get the 2 X 7950's although I suppose there is a chance a a later date, I tend to upgrade hardware every 1-2 years anyway.

Would I be better off getting the HIS or MSI Boost cards instead to allow for future overclocking?

ICDP · 31 Mar 2013 at 21:48

Rusty0611 said:
LOL what?

I'm not saying it doesn't equal more heat, I'm saying it doesn't necessarily equal unacceptable temperatures. I'm confused you don't understand.

Fair enough I did say it would reach unacceptable temperatures, sorry about that I should have worded that better. This doesn't change the fact that it is much better to have card that allows voltage control than one that ruins 1.25v locked.

Rusty0611 said:
Well you must do if your cards at stock are the same as mine at 1.25V

Yet again I am having to re-quote myself.

"the 2x 7950s are running 1050/1550 1.031v. My case has plenty of airflow and the cards run at ~70c top ~60c bottom with a non-aggressive fan profile".

So I have specifically set both of my cards to run lower fan speeds than stock because I prefer a quiet fan profile. If they were to run stock fan speeds they would run even cooler.

Rusty0611 · 31 Mar 2013 at 21:59

I didn't say you said that, I just said it wouldn't necessarily translate to high temps having 1.25V...

Jeez isn't this difficult

.