Most important for a power supply is the 12V rail. For stability purposes, having a single beefy 12V rail is better than multiple, weaker 12V rails.
And depending how high you clock it, a single Radeon 7970 draws anywhere from 200-250W. For overclocking the gpu's, I would recommend using MSI Afterburner (works even if you don't have an MSI card). Also, the reference Radeon 7970 (single fan shrouded) are vastly inferior to the custom cooling solutions (eg MSI Frozr, Sapphire OC Edition) if you're talking about noise levels and overclocking potential.
Topic: Four 7970's crossfired in windows (Read 943 times)
Make sure you have a beefy PSU for you rig as my rig pulls 620w from the wall with just 2 cards; idles at 100.
Keep in mind that because of constant power draw that mining requires that a good quality lower wattage power supply (e.g. 850W) is much better than a so so one that's much high (e.g. 1,000W).
For 4 7970 I think a good quality 1100W+ power supply is required.
Each card will draw 210 watts, so that's 840 watts on graphics cards alone. You should probably budget for at least another 200 watts for the rest, so 1.1kw sounds about right.
Make sure you have a beefy PSU for you rig as my rig pulls 620w from the wall with just 2 cards; idles at 100.
Keep in mind that because of constant power draw that mining requires that a good quality lower wattage power supply (e.g. 850W) is much better than a so so one that's much high (e.g. 1,000W).
For 4 7970 I think a good quality 1100W+ power supply is required.
I have 2 7970's running in this machine right now. I have the crossfire bridge connected, but crossfire disabled. Using cgminer and running at 1150/1000 for 685 on each card.
Make sure you have a beefy PSU for you rig as my rig pulls 620w from the wall with just 2 cards; idles at 100.
Make sure you have a beefy PSU for you rig as my rig pulls 620w from the wall with just 2 cards; idles at 100.
Try cgminer as an alternative to Guiminer. It's not that much more complicated to setup and as a side benefit it handles all the GPUs together instead of as separate workers with Guiminer. Cgminer can also control fan speed/gpu& mem clock speed/voltage without using any other software. It also appears to give ~3% better hash throughput.
I plan on overclocking all of em too. Bring the memory bus down and up the core clock, increase the voltage. That's what you wanna do right? Of course be safe, but that is the method to get the most; correct??
Indeed I did. I paid 370 for each card. Got them off of tigerdirect.com via slickdeals.net
I really don't mind loud. I'm a bachelor and loudness has never really been an issue with me. I live in an apartment and my computer is about six feet away from the air conditioner. Helps keep it cool. I'll set in trixx to have a set fan speed. One that isn't too loud with four cards but at the same time keeps them cool.
Might need to make sure you will have proper cooling, especially if they are going all on the same mobo. Mine are in an open environment so are not that bad, but I have a fan on my 5970 cause that thing will get LOUD otherwise.
I was planning on running 4 in mine, but I feel best that I just run 3. Even with coolers on them the middles ones just couldn't get enough airflow.
Did you pick up those Visiontek ones for uber cheap? I thought about buying 1 or 2 of those but I don't dig reference coolers anymore so opted out. :-/
When you game, if you game, just enable crossfire when you game. With those cards, you don't even really need to crossfire unless you are running eyefinity.
I was planning on running 4 in mine, but I feel best that I just run 3. Even with coolers on them the middles ones just couldn't get enough airflow.
Did you pick up those Visiontek ones for uber cheap? I thought about buying 1 or 2 of those but I don't dig reference coolers anymore so opted out. :-/
When you game, if you game, just enable crossfire when you game. With those cards, you don't even really need to crossfire unless you are running eyefinity.
Indeed I did. I paid 370 for each card. Got them off of tigerdirect.com via slickdeals.net
I really don't mind loud. I'm a bachelor and loudness has never really been an issue with me. I live in an apartment and my computer is about six feet away from the air conditioner. Helps keep it cool. I'll set in trixx to have a set fan speed. One that isn't too loud with four cards but at the same time keeps them cool.
Thank you all so much! That was so very helpful! 
You can have the crossfire cable physically installed, but it's recommended that you just turn crossfire off in the ATI control panel.
There's no need, but since you asked 
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Might need to make sure you will have proper cooling, especially if they are going all on the same mobo. Mine are in an open environment so are not that bad, but I have a fan on my 5970 cause that thing will get LOUD otherwise.
I was planning on running 4 in mine, but I feel best that I just run 3. Even with coolers on them the middles ones just couldn't get enough airflow.
Did you pick up those Visiontek ones for uber cheap? I thought about buying 1 or 2 of those but I don't dig reference coolers anymore so opted out. :-/
When you game, if you game, just enable crossfire when you game. With those cards, you don't even really need to crossfire unless you are running eyefinity.
I was planning on running 4 in mine, but I feel best that I just run 3. Even with coolers on them the middles ones just couldn't get enough airflow.
Did you pick up those Visiontek ones for uber cheap? I thought about buying 1 or 2 of those but I don't dig reference coolers anymore so opted out. :-/
When you game, if you game, just enable crossfire when you game. With those cards, you don't even really need to crossfire unless you are running eyefinity.
Btw, what's your bitcoin address. If it works without any additional configs then I'll donate to you. Thanks man!
So would this work? I run guiminer and run four individual opencl miners and I'm golden? Sorry guys. I really need this help.
Yup. That should do it.
So would this work? I run guiminer and run four individual opencl miners and I'm golden? Sorry guys. I really need this help.
I believe it's advised that you don't run them in Crossfire at all. Instead, run them independently and run multiple mining instances, one for each card. Of course, not using Crossfire means you'll have no benefit from the additional cards when it comes to gaming (if that's a concern).
What do I have to do to prepare for the four 7970's I'm going to put in my new mining machine. It'll be running windows and I want the best performance. I tried to do it on my friends machine and it wouldn't work right because it had the crossfire bridge on. How do you use all four cards in windows 7?
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