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I would like to put one ati card 7970 on a pc where there is already an hard disk and a cdrom. The pc is a pentium 4 3.2Ghz.
What is the minimun power PSU I have to buy?

Regards,
ilpirata79

A good 750w with single rail and at least 80+ rated, But in my opinion its not worth it on a P4, It will bottle neck performance and you will not get full use out of the GPU. But if you plan on upgrading the rest of the system at a later date then rock on.

EDIT - Some people say that 750w is too much, I have had alot of bad issues with running too close to rated so I always over power and it has yet to let me down. Just thought I would get that in before anyone else, You can go less, But in my experience not worth it.

I'm pushing the friendship but I'm running a Gigabyte HD7970 @ 720khash (LTC) with a Core 2 Duo 2.67GHz with a Thermaltake 500w psu  ;D

500 gold certified sounds fine to me

or a 550 silver or 600 bronze

if you dont have many other peripherals, (no fancy sound card or anything, eh?)

Agreed that 550-650 is enough.  Though a 750 will breath nice and easy.

For reference I used to have an antec 520 powering two of my overclocked 7970s running full throttle 24/7.  It handled it just fine.   I wouldn't plan to max out a psu for an extended period of time though.

The AMD web site says 500W or more, so theoretically any 500W PSU should work. However, this doesn't really work that well in practice.

A single 7970 should use close to 20A on a 12V rail, and so try and find one that can do at least that much. Translation: Buy a Single Rail PSU

This PSU (http://www.newegg.com/Product/Product.aspx?Item=17-171-038) is a 550W, but it has 2 rails that can only do 16A each. One rail will be for your system, and one rail for the GPU. 16A is not enough to power a GPU for more than 200W, which the 7970 is ~225-250W.

This PSU (http://www.newegg.com/Product/Product.aspx?Item=N82E16817494002) is only 500W, but it was 1 rail that can do 34A. That's plenty of juice for a 7970 to pull from, esp since the rest of your computer will be sitting idle most of the time.

What if I use a single 400W PSU only for the graphic card and attach the rest to a different PSU?
I have a spare PSU...

Wow, the second one is  really cheap! Does it have six connectors though?
Regards,
ilpirata79

PCI-Express Connector: 1 x 6-Pin, 1 x 6+2-Pin

That's enough for a 7970.

Just keep in mind the 7970 is a dual 8pin, so you'll need one of those molex adapters.  I'd just grab a quality psu that had a dual 8pin on it.

My testbed is a dual core athlon, hard drive, etc. It uses a 450 watt rosewill capstone with a kill-a-watt. with radeon 7970 20% powertune on OCCT:GPU:3D (this uses a LOT of gpu electricity), the entire rig pull about 330-380 watts at the wall. It's not uncommon for the GPU to approach 90C on auto fan while being burned in with occt (this is like furmark, but better)

Uhh, not it's not. 7970 and 7970GHz Edition are both a 6+8, which the PSU I linked has.

http://us.hardware.info/reviews/2847/2/amd-radeon-hd-7970-ghz-edition-review-radeon-hd-7970-ghz-edition

I guess it depends on the card, the Sapphire I have are all dual 8s

What about a PSU with 450W ?

What can happen if it is not sufficient?

Regards,
ilpirata79

If a psu is not sufficient the computer will randomly reboot when you start taxing the system, or in some cases not start up at all.

Could it burn from the ground up? I think so...

An underpowered PSU will not burn or destroy anything. However, a cheap nasty one, will. There's a difference.

I actually think a 450W one will work for a single 7970, but same as what I said before, it has to be a single rail, and it can't be from a cheap manufacturer. Only use trusted brands.

Edit: I would trust This PSU (http://www.newegg.com/Product/Product.aspx?Item=N82E16817182066) to power a 7970, even tho it's only a 450W. However, it's actually more expensive than the 500W I mentioned earlier, so idk why you'd want to do that.

Here's a corsair you could grab, on the middle of the page with rebate.

http://www.newegg.com/DailyDeal.aspx?name=DailyDeal&cm_sp=Dailydeal-_-adlink-_-06192013&Page=2

The PSU is this one... not even 450W

https://www.dropbox.com/s/wmkz3rz85tzrzxf/foto.JPG

Do you see the image?

Now I am mining. I am getting this kind of output:


[2013-06-19 17:20:41] Started cgminer 3.2.1                    
 [2013-06-19 17:20:41] ADL found less devices than opencl!                    
 [2013-06-19 17:20:41] There is possibly more than one display attached to a GPU                    
 [2013-06-19 17:20:41] Use the gpu map feature to reliably map OpenCL to ADL                    
 [2013-06-19 17:20:41] WARNING: Number of OpenCL and ADL devices did not match!                    
 [2013-06-19 17:20:41] Hardware monitoring may NOT match up with devices!                    
 [2013-06-19 17:20:41] Probing for an alive pool                    
 [2013-06-19 17:20:46] Disabling extra threads due to dynamic mode.                    
 [2013-06-19 17:20:46] Tune dynamic intensity with --gpu-dyninterval                    
 [2013-06-19 17:20:46] Network diff set to 19.3M                    
 [2013-06-19 17:20:47] Thread 1 being disabled                    
 [2013-06-19 17:20:47] Accepted 89b09b1f Diff 1/1 GPU 0                    
 [2013-06-19 17:20:47] Accepted bf4c5bca Diff 1/1 GPU 0                    
 [2013-06-19 17:20:51] Accepted e9393ace Diff 1/1 GPU 0                    
 [2013-06-19 17:21:03] Accepted 120d6aa9 Diff 14/1 GPU 0                    
 [2013-06-19 17:21:12] Accepted 6d427b75 Diff 2/1 GPU 0                    
 [2013-06-19 17:21:14] Accepted 2b3a7eaf Diff 5/1 GPU 0                    
 [2013-06-19 17:21:19] Accepted 16a57197 Diff 11/1 GPU 0                    
 [2013-06-19 17:21:28] Accepted cffb12ca Diff 1/1 GPU 0                    
 [2013-06-19 17:21:35] Accepted 33fe23c3 Diff 4/1 GPU 0                    
 [2013-06-19 17:21:42] Accepted 3ef7e995 Diff 4/1 GPU 0                    
(5s):514.9M (avg):515.9Mh/s | A:10  R:0  HW:0  U:10.0/m  WU:10.0/m          
 [2013-06-19 17:21:48] Accepted 9d5a32b8 Diff 1/1 GPU 0                    
 [2013-06-19 17:21:56] Accepted 8508d7e3 Diff 1/1 GPU 0                    
 [2013-06-19 17:22:00] Accepted 0c5e8bc3 Diff 20/1 GPU 0                    
 [2013-06-19 17:22:11] Accepted 16e65470 Diff 11/1 GPU 0                    
 [2013-06-19 17:22:28] Accepted 4be54530 Diff 3/1 GPU 0                    
 [2013-06-19 17:22:34] Accepted 8c55d389 Diff 1/1 GPU 0                    
 [2013-06-19 17:23:19] Accepted 76f45afe Diff 2/1 GPU 0                    
 [2013-06-19 17:23:28] Stratum from pool 0 requested work restart                    
 [2013-06-19 17:23:30] Accepted f3cbf634 Diff 1/1 GPU 0                    


Can the PSU continue in your opinion?

Regards,
ilpirata79  

go on ebay and buy a used hx750 for £50-60 and you will be ok for 2 7970s standard or 3 7950s

Let me add some more details:

the CPU is mostly idle.

THe psu delivers hot air for sure... but it's not very noisy.

The GPU is quite hot. Am I sure that it will not burn?

Finally, I noticed that the pool site shows less mega hashes for my worker... now around 447.

Regards,
ilpirata79

Corsair is good brand. I would trust that to run a 7970 with no issues.

BTW, I tried googling pics for that CX500, and it turns out they're Really, Really Nice! (http://www.moto-verso.co.uk/wp-content/uploads/2012/11/277856_391667714230310_1935612013_o.jpg).

I will maybe buy a new one, but for the moment I can only use that one, which is:

Q-tec  400W big fan...

I have posted a photo. can you see it?

Regards,
ilpirata79

Yep, I can see the pic just fine.

That 400W PSU can only handle 18A on the 12V line, and that's shared with your system (MB/CPU/RAM/HDD/etc). Your PSU is giving it all its got to power you GPU, so no wonder the PSU is hot. It's not really designed to run max out like that.

Your PSU should not have any effect on your GPU temps, unless you PSU is dumping it's hot air inside the case, which I doubt. What are your GPU temps, anyways?

I assume by only running just over 500MH/s that you're not overclocking at all. That's good, for this PSU.

I would strongly recommend upgrading. That Corsair CX500 for $30 looks about as good a deal as any. If you're going to mine on a $350 GPU, you can spend 1/10th of that to make sure you're not going to damage it in any way.  ;) :D ;D 8)

I am not overclocking (--auto-fan --temp-target 75 --thread-concurrency 8192 -g 2 -I 13 -w 256) and I get 557Mh/s.

Here's the temperature. I set a target of 75°, so it's a bit strange:

Default Adapter - AMD Radeon HD 7900 Series
                  Sensor 0: Temperature - 77.00 C

I will upgrade for sure if I find that Corsair. In the meantime do you think I can go to sleep without risking burning the house? :))

Regards and thanks,
ilpirata79

very nice indeed :D

If I really want to get something very little noisy,
what about this one:

http://www.ebay.it/itm/Corsair-Builder-Series-CMPSU-750CX-750W-/181068972536?pt=Alimentatori_per_PC_e_Server&hash=item2a288d41f8&_uhb=1#ht_2461wt_1165
?

Regards,
ilpirata79

hx 750 are only slightly louder but are cheaper

They are less cheap... http://www.ebay.it/itm/CORSAIR-Alimentatore-Corsair-PC-HX750-80PLUS-Gold-CP-9020031-EU-/400479964989?pt=Altro_Informatica&hash=item5d3e774f3d&_uhb=1

im in the uk lol one sold lastnight for £35+£4.99 p&P

This is the exact same power supply I use for testing and burning in  power hungry cards such as 5970 and 7970. I recommend it as well for the purpose of running a single 7970. For what it's worth, I run two 5970 on one of my 450 watt capstones, but undervolted while overclocked. No burning smell, very little heat, no random reboots, nothing. Rock solid.

Sure... http://www.ebay.co.uk/sch/i.html?_odkw=hx+750&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.Xhx+750+corsair&_nkw=hx+750+corsair&_sacat=0

regards,
ilpirata79

it was bidding lol  if i see another one going that cheap i will post it up for you

The PC I was running the 400W psu is not responding anymore...
I even tried to run it while overclocking the graphic card (hd 7970, 1100Mhz core, 1350Mhz memory).

Just to be prepared to the worse: have I ruined the graphic card? Its fan is spinning though.

The hard disk does not turn on at all...

Could it be that I've just ruined the PSU?

Regards,
ilpirata79

I will start and try to extract the hard disk and see if it works...

regards,
ilpirata79

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139028

this will work fine. it is 600w, bronze certified, and single rail. with the promo code and rebate included, it is only $37.99. corsair being a reputable company is a plus.