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Topic: Dual PSU combine different PSUs (Read 665 times)

hero member
Activity: 966
Merit: 506
October 03, 2017, 11:57:09 AM
#10
No one is clicking a link here on the forum. Generally, too much output is not a problem on a PSU and the brand is meaningless, other than some are better than others. It is kind of like asking if you can use a 20 foot van to move your box of crayons. Yes, it should be fine, but make sure that you check and double check everything, as it always true with rig building.
sr. member
Activity: 336
Merit: 253
Gone phishing...
September 21, 2017, 09:27:02 PM
#9
You do not "need" to purchase an add2PSU or a 24-pin "splitter" (does not function as most would expect a splitter to) cable.

Many EVGA PSUs come with a "power-on self tester", which is essentially a dummy plug that simulates the PSU's connection to the motherboard, telling the PSU to be "on". If yours do not, then you can take a paper clip and short the green pin to any black ground. (Unfortunately, many PSUs today have uniformly-colored cables, so you might need to find a pinout diagram and do some careful counting.)

With the paper clip trick, ensure that the secondary PSU (the one NOT used for powering the motherboard) is forced on prior to booting.


Additionally, know that you are still responsible for ensuring that the load is balanced safely between your two PSUs, with neither pushed too close to the maximum rating. Using more than two PSUs adds additional considerations about distributing the load. (It'd be even worse if one of your PSUs had more than one 12V rail, but thankfully yours shouldn't.)
sr. member
Activity: 784
Merit: 282
September 21, 2017, 07:00:29 PM
#8
It is always better to use a single PSU for power efficiency and retail price savings. Just get one with high enough wattage to support your GPU power draw.

To answer your question directly, yes different power supplies will work together regardless of brand or wattage. What you need to make them both work is ADD2PSU: a product that allows you to activate both power supplies with the system. Or you could use the "paperclip technique" to activate both PSUs. Just google search them results are at the top.
full member
Activity: 219
Merit: 100
September 21, 2017, 06:15:39 PM
#7
Just use a server PSU that's always powered on for the PCI-e power connectors on the VGA cards, standard PSU for the rest. Cheap, efficient, has never failed me yet.
full member
Activity: 210
Merit: 100
September 21, 2017, 05:32:42 PM
#6
yeah i understand, but the problem is that if you have like for example 8 gpus and you need 2x 8pin vga cable for each, you will need 16 cables.
Which is ok when i consider 2x 1600 psus. BUT there is no way of having all gpus on 1 psu. and the rest on the second one.
i

You can run some of the gpu's to one and fill up the other PSU.. I have everything connected to one PSU (mobo, risers, sata, etc.) and an additional 2 GPUs, and then the remainder GPU's (VGA 8+6) connectors connected to the other GPU.. The EVGA power supplies comes with a little plastic black tester, I just hook that up to the 2nd PSU and then turn it on using the On/Off switch in the back seconds to booting up the mobo and it works like a charm.
member
Activity: 1092
Merit: 67
September 21, 2017, 05:29:05 PM
#5
lower rated psus normally do not have a single 12v rail. this will cause you problems when trying to use them for mining
newbie
Activity: 42
Merit: 0
September 21, 2017, 02:48:00 PM
#4
yeah i understand, but the problem is that if you have like for example 8 gpus and you need 2x 8pin vga cable for each, you will need 16 cables.
Which is ok when i consider 2x 1600 psus. BUT there is no way of having all gpus on 1 psu. and the rest on the second one.
i
sr. member
Activity: 861
Merit: 281
September 21, 2017, 01:17:50 PM
#3
You can definitely use the cable that you have mentioned. It'll work just fine to connect your PSUs in one system. Just for future, you'll be better off if you consider same rating and same company PSU for dual PSU set-ups. It's better that way.
As philejmath said:
Quote
All risers, cpu, mobo, sata on one PSU and all the GPUs on the second PSU.
Is the best way for dual PSU configuration.
newbie
Activity: 17
Merit: 0
September 21, 2017, 11:57:43 AM
#2
I have a 750W Corsair and a 1000W EVGA in one rig, combined with this http://www.add2psu.com/

Haven't had any problems yet.

I thought the same about the riser and GPU but what ended up working for me is:

All risers, cpu, mobo, sata on one PSU and all the GPUs on the second PSU.  If I didn't do it this way the cards in the risers connected to the second PSU would not be recognized.

-phil
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