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ProfileJoseph Stateson
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Message 69024 - Posted: 12 Sep 2019, 20:10:46 UTC

Trying to figure if my 850 seasonic 80+ gold is close to capacity as I want to add additional boards to the miner.

Read the following at WiKi:
The 80 Plus Gold rating meas that the PSU is rated for at least 87% efficiency at 20% load, 90% at 50% load, and 87% at 100% load


I have four S9000 type boards and the wall wattage shows only 710 watts mining for "milkyway". Since TDP of S9000 is 225 watts there is no possibility of having to plan for 225 watts each.

If the unit puts out exactly 850 watts then dividing by .87 gives 977 wall watts exactly.

The rise from 710 to 977 is 267 watts and %87 of that is 232 so I should be able to add up to 223 watts.

Making things difficult is the label showing the following that add to about 955 watts which goes over the 850 rating

3.3/5: 100w
12v: 840w
-12v 3.6w
+5v 12.5

i7-4790S is 65watts
Two sticks memory 15+15 watts?
tb85 mining mombo ?
ssd ?
misc fans, usb, etc ?

I am thinking that even if I don't know the mombo and other misc wattage, that "spare 232" watts should be a good number?
There are 7 Pcie 6+2 connectors available.
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ProfileKeith Myers
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Message 69025 - Posted: 13 Sep 2019, 1:17:41 UTC

90% at 50% load


Notice this spec? That is where you should operate a power supply. If you have a 977W load, you should run at least a 1200-1300W power supply. I would feel more comfortable with a 1600W power supply. For my 1000W loads, that is what I run.
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ProfileJoseph Stateson
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Message 69026 - Posted: 13 Sep 2019, 3:34:11 UTC - in response to Message 69025.  
Last modified: 13 Sep 2019, 3:46:22 UTC

90% at 50% load


Notice this spec? That is where you should operate a power supply. If you have a 977W load, you should run at least a 1200-1300W power supply. I would feel more comfortable with a 1600W power supply. For my 1000W loads, that is what I run.


Did not want to buy a bigger one else you are correct.

Just added an HD7950

Already have three s9000 and one s9100. All but one on risers using TB85 mining board.

Strange, the names have all changed but OpenCL is working fine, running 5 WUs per board.
Only the hd7950 is identified correctly
6			9/12/2019 10:20:04 PM	OpenCL: AMD/ATI GPU 0: AMD FirePro W8000 (driver version 1912.5 (VM), device version OpenCL 1.2 AMD-APP (1912.5), 6144MB, 6144MB available, 3226 GFLOPS peak)	
7			9/12/2019 10:20:04 PM	OpenCL: AMD/ATI GPU 1: ATI FirePro V (FireGL V) Graphics Adapter (driver version 1912.5 (VM), device version OpenCL 2.0 AMD-APP (1912.5), 12288MB, 12288MB available, 4608 GFLOPS peak)	
8			9/12/2019 10:20:04 PM	OpenCL: AMD/ATI GPU 2: AMD FirePro W8000 (driver version 1912.5 (VM), device version OpenCL 1.2 AMD-APP (1912.5), 6144MB, 6144MB available, 3226 GFLOPS peak)	
9			9/12/2019 10:20:04 PM	OpenCL: AMD/ATI GPU 3: AMD FirePro W8000 (driver version 1912.5 (VM), device version OpenCL 1.2 AMD-APP (1912.5), 6144MB, 6144MB available, 3226 GFLOPS peak)	
10			9/12/2019 10:20:04 PM	OpenCL: AMD/ATI GPU 4: AMD Radeon HD 7900 Series (driver version 1912.5 (VM), device version OpenCL 1.2 AMD-APP (1912.5), 3072MB, 3072MB available, 3686 GFLOPS peak)	


Before I added the hd7950 win10 thought they were all ATI FirePro V, even gpu-z got fooled. However, milkyway identified them correctl (Hawaii & Tahiti)

My wall outlet watt meter shows 910 watts. The seasonic focus output is rated at 850 so I think that is ok as when I multiple .87 times 910 I get 791 watts which is under the 850 limit. That assume 87% efficiency. We had a storm recently and temps dropped else I would not be running this. I stopped all SETI after that WOW event.
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Message boards : Number crunching : Figuring out power supply limits

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