Need Help on Deciding on a 4 7950 Cards

[bitbyebit]

Hello:  I am going to buy 4 7950's but cannot decide.  Can you guys give your opinion?

Qualities that I am looking for in a card:

1) Can be voltage changed.
2) Can overclock/underclock
3) Have a good reputation.
4) Can perform 600-700 (or more if somehow possible)

What 7950 would you suggest that would do this?

I keep reading and seeing that the Sapphires are great, but then I see this Gigabyte card and it makes me think twice.  I want to have the option to change the voltage.

These are the 3 cards I have been looking at:
GIGABYTE GV-R795WF3-3GD (Can't change voltage unless it's reprogrammed)
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125414

SAPPHIRE Vapor-X 100352VXSR Radeon HD 7950 3GB 384-bit
http://www.newegg.com/Product/Product.aspx?Item=N82E16814202003

Sapphire Radeon HD 7950 3GB DDR5
http://www.amazon.com/gp/product/B00BXVFM3K/ref=ox_sc_act_title_3?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

I'm working on my first rig. Thanks.

[1714881828]

1714881828

[1714881828]

1714881828

[1714881828]

1714881828

[crazyates]

It's really a toss up between that Gigabyte 7950, and the Sapphire 4L ones: http://www.newegg.com/Product/Product.aspx?Item=N82E16814202030

I've heard nothing but amazing things from both.

The Gigabyte ones are voltage locked, at 1.25V, but there is a way around this. There is an older version of the BIOS (F43) for the card that runs at 1.09V, and does a lot for keeping the power down and cooling the cards.

I can't remember if the 4L ones are voltage unlocked, but the reference fan is a lot better for managing your airflow if you have a lot of cards.

[nwoolls]

I have the Sapphire Radeon HD 7950 from Amazon. The voltage is unlocked and stock is 1.08. I am able to get about 610 Mh/s with the voltage upped to 1.09, the core at 1190, the memory at 200 and the fan at 75%. The 2 GPU's I have going right now sit at 58 - 60C without risers.

[bitbyebit]

I have the Sapphire Radeon HD 7950 from Amazon. The voltage is unlocked and stock is 1.08. I am able to get about 610 Mh/s with the voltage upped to 1.09, the core at 1190, the memory at 200 and the fan at 75%. The 2 GPU's I have going right now sit at 58 - 60C without risers.

Thanks nwools.  I appreciate you chiming in and giving me this info.  Do you mean the Sapphire in my link?  I'm leaning to the Sapphire but the Gigabyte looks so good as well.

[nwoolls]

Thanks nwools.  I appreciate you chiming in and giving me this info.  Do you mean the Sapphire in my link?  I'm leaning to the Sapphire but the Gigabyte looks so good as well.

Yup I have exactly those from Amazon. They seem to work well. If I try to go higher than 1190 I'll start to get occasional HW errors and anything over 1205 would give me a sick GPU in cgminer.

Also Amazon refunded me some $ when the hardware I bought went down in price on their site a couple weeks after I ordered. They will also replace a card with next-day delivery and pre-paid postage if there's anything wrong with it. Pretty nice experience overall, and happy with the performance.

[superfastkyle]

This is only if you get a good asic quality. He obviously has an over 75% card. You probably won't get this good of a card. Some sapphire reference run at much higher volts/temps. One of the ones I got uses over 250 watts to hit about 575 mhash. On the other hand I have some vapor-x cards as well. Even bad asic quality ones run low wattage but they may max out at about 550 mhash or so. Personally I like the vapor x more but they do have a higher price

I have the Sapphire Radeon HD 7950 from Amazon. The voltage is unlocked and stock is 1.08. I am able to get about 610 Mh/s with the voltage upped to 1.09, the core at 1190, the memory at 200 and the fan at 75%. The 2 GPU's I have going right now sit at 58 - 60C without risers.

[az12]

I can recommend the Gigabyte ones although the voltage is locked as mentioned above the f43 Bios drops the voltage to 1.09 (Although the HDMI port wont work with this firmware). Mine run cool and get about 600Mh/s each. Two draw about 580 watts on my machine when paired with a sempron 145.

[bitbyebit]

That Giagabyte sure looks like it would keep cool with those three fans.

[miningdude]

Hello:  I am going to buy 4 7950's but cannot decide.  Can you guys give your opinion?

I'm working on my first rig. Thanks.

I love the Sapphires. They are easy to undervolte/overclock, run relatively cool (if on PCI-e risers), and get 600+ in my experience. Either the twin fan or the reference design single fan units work well. I got the twin fan units back when they were around $280 / ea. I wrote about building my first mining rig here: http://www.coinminingrigs.com/my-first-mining-rig/ and have written additional step-by-step build guides using the most cost effective parts available.