[SOLVED] Can i use 4pin cpu connector on 8pin mono

John Malik

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Dec 18, 2020
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Hello everyone. I want to buy asrock b350m pro4 mobo with ryzen 3 1200. That mobo requires 8pin for cpu but i only have 4pin. Can i use 4pin becouse ryzen 3 1200 is only consuming 65w? I think maybe these 8pins are planned for much stroger cpus with higer tdp
 
Solution
That should be fine. It's not best practice but unless you're OC'ing or intend to use a more powerful CPU, 4-pin power in an 8-pin slot for that CPU ought to be enough.

OrlyP

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Aug 20, 2020
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That should be fine. It's not best practice but unless you're OC'ing or intend to use a more powerful CPU, 4-pin power in an 8-pin slot for that CPU ought to be enough.
 
Solution

DSzymborski

Curmudgeon Pursuivant
Moderator
What exact PSU are we talking about here? If the PSU is either low-wattage enough or low-quality enough to only have a single four-pin CPU connector in this day and age, I'd be extremely skeptical about pairing it with a GPU that can draw nearly 175W.
 

DSzymborski

Curmudgeon Pursuivant
Moderator
Is this your power supply? If so, I wouldn't count on being the owner of a GTX 970 for very long.

Untitled.png


If so, this is a fake 650W power supply. It's a low-quality 400W (at best) with no protections and designed for PCs that have been obsolete for 20 years. You see this (and similar) literal garbage occasionally foisted on unsuspecting users in SE Europe.
 
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Karadjgne

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That's not a 650w psu, or anything close. Anything with a 4pin EPS is under @ 400w at best. As a comparison, my 520w Seasonic M12-II had 8pin eps, 6pin pcie, 6+2pin pcie and a solid 480w 12v output on 40A rail. The Zeus unit has 2x rails rated at 24A, for a combined amperage of @ 40A. (if it's lucky, which it almost certainly isn't.

View: https://m.youtube.com/watch?v=f6snWfd1v7M


This is the same classification psu as yours, look at rated wattage vs failing wattage.

GTX970 can use @ 170w, regardless of actual listed TDP. Puts your pc in the 320w-340w range maxed out, with gaming loads closer to 250w-260w.

In a nutshell, keep a fire extinguisher handy, that's how bad the store ripped you off, selling something represented as decent because it's '650w'.
 
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OP, throw that PSU lookalike out of the window and get proper PSU instead. Any Tier C PSU with power output 500+W will suffice. This thing you have now is cheap group regulated low wattage PSU for office computers with integrated GPU. I doubt that it even can support 400W properly. Do not use it if you want to avoid magic smoke smell in your room and probably fried motherboard and GPU with that.
 

John Malik

Commendable
Dec 18, 2020
43
3
1,545
OP, throw that PSU lookalike out of the window and get proper PSU instead. Any Tier C PSU with power output 500+W will suffice. This thing you have now is cheap group regulated low wattage PSU for office computers with integrated GPU. I doubt that it even can support 400W properly. Do not use it if you want to avoid magic smoke smell in your room and probably fried motherboard and GPU with that.
I will order a new psu today. I am planning on something like lc power lc6550 v2.2. It's 80 plus bronze super silent edition.
 

Karadjgne

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And almost the same psu as you have now, with a different paint job.

Think about it, it's telling you it's super silent edition. Does that mean all the other LC Power units sound like freight trains?

The 80+ is participation (hopefully) in a 3rd party outfit (called 80+) who tests the units efficiency. That's all. It's a certification, not even a standard. Normally it means you've got better 'guts' inside, with better components and circuitry, but not always. You can still use the cheapest, most miserable resistors, diodes, coils and caps and get decent efficiency, but they die in months.

So don't rely on flashy names, rgb, or other gimmicks, the better psus don't need to advertise that stuff.
 
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I will order a new psu today. I am planning on something like lc power lc6550 v2.2. It's 80 plus bronze super silent edition.
Now you will replace the PSU which certainly will blow up during gaming with GTX 970 to Tier D PSU made for PCs with iGPU. It maybe will be sufficient, but maybe will brownout in game with spontaneous reboot. At least it is less possible that your desired PSU will blow up :)
Maybe look into this list


and check if you can have some 500..550W PSU from Tier C.
 

John Malik

Commendable
Dec 18, 2020
43
3
1,545
And almost the same psu as you have now, with a different paint job.

Think about it, it's telling you it's super silent edition. Does that mean all the other LC Power units sound like freight trains?

The 80+ is participation (hopefully) in a 3rd party outfit (called 80+) who tests the units efficiency. That's all. It's a certification, not even a standard. Normally it means you've got better 'guts' inside, with better components and circuitry, but not always. You can still use the cheapest, most miserable resistors, diodes, coils and caps and get decent efficiency, but they die in months.

So don't rely on flashy names, rgb, or other gimmicks, the better psus don't need to advertise that stuff.
Okay thanks for the help! I searched on the internet and will order Gembird GMB-600-PRO 600w 80 plus bronze with active PFC and OVP / UVP / OPP / SCP. I also has 2x 6pin connectors for graphics, so i think it will be enough to handle gtx 970.
 

John Malik

Commendable
Dec 18, 2020
43
3
1,545
That's not a 650w psu, or anything close. Anything with a 4pin EPS is under @ 400w at best. As a comparison, my 520w Seasonic M12-II had 8pin eps, 6pin pcie, 6+2pin pcie and a solid 480w 12v output on 40A rail. The Zeus unit has 2x rails rated at 24A, for a combined amperage of @ 40A. (if it's lucky, which it almost certainly isn't.

View: https://m.youtube.com/watch?v=f6snWfd1v7M


This is the same classification psu as yours, look at rated wattage vs failing wattage.

GTX970 can use @ 170w, regardless of actual listed TDP. Puts your pc in the 320w-340w range maxed out, with gaming loads closer to 250w-260w.

In a nutshell, keep a fire extinguisher handy, that's how bad the store ripped you off, selling something represented as decent because it's '650w'.
Don't be rude. Store didn't ripped me off i bough this computer with plans to change psu, cpu and other components.
 

Karadjgne

Titan
Ambassador
Oh, I wasn't trying to be rude. Almost all ppl who get a pc that has a psu like yours are suckered into buying them, because they don't know what the difference is. It's a store tactic used worldwide, for a lot of things, sell the biggest hunk of junk they can for a decent price, sometimes they'll even throw in a discount to sweeten the deal. You buy a $60 psu that cost them $8. They don't like to sell even a $120 really good psu because it cost them $80 in the first place. Lower profit margin, higher overhead.

650w psu for a 65w cpu and a 70w gpu and a whole pc that only runs 150-200w at most. But it's got a 650w psu! That's great! Bigger is better! For an extra $18, we'll upgrade you to a 700w psu!

And ppl fall for that, all day long.
 
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Karadjgne

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Noooo lol. It usually lasts for 3 days ± past the store warranty period 🤣.

Then you get, "ok we fix for $120, but upgrade to 850w model!" that puts the pc Well beyond any crappy psus load tolerances. Of course it's another $10 unit with 4 independent rails rated at 12/12/14/16 amps and has a single pcie 6pin and a floppy dongle, non modular, and uses adapters to convert the molex into Sata power. But it's 850w!

Gembird GMB-600-PRO 600w.
Nominal 35A, (really? that's just over 430w continuous) and peak (that's what it'll handle a spike upto) of 48A, which is 576w....

They tell you straight up not to run continuous loads of more than @ 430w, or it'll roast, but if you do hit it hard, make it really short and it'll put out upto 576w.

A GOOD 600w (there aren't really any in atx firm factor) will put out just about 600w continuous and not blink. I understand budgets (raised 4 kids and support mother-in-law) and understand availability (India markets are not exactly brilliant) but serious advice, stop shopping in the lowest catagory, you won't find anything but wasted money that's too hard to get in the first place.

Even a Corsair VS 550w, CX 550w, CXM 550w would be about a half dozen steps upgrade in quality, far more dependable, and have proven protective circuitry that'll handle your pc just fine.
 
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John Malik

Commendable
Dec 18, 2020
43
3
1,545
Noooo lol. It usually lasts for 3 days ± past the store warranty period 🤣.

Then you get, "ok we fix for $120, but upgrade to 850w model!" that puts the pc Well beyond any crappy psus load tolerances. Of course it's another $10 unit with 4 independent rails rated at 12/12/14/16 amps and has a single pcie 6pin and a floppy dongle, non modular, and uses adapters to convert the molex into Sata power. But it's 850w!

Gembird GMB-600-PRO 600w.
Nominal 35A, (really? that's just over 430w continuous) and peak (that's what it'll handle a spike upto) of 48A, which is 576w....

They tell you straight up not to run continuous loads of more than @ 430w, or it'll roast, but if you do hit it hard, make it really short and it'll put out upto 576w.

A GOOD 600w (there aren't really any in atx firm factor) will put out just about 600w continuous and not blink. I understand budgets (raised 4 kids and support mother-in-law) and understand availability (India markets are not exactly brilliant) but serious advice, stop shopping in the lowest catagory, you won't find anything but wasted money that's too hard to get in the first place.

Even a Corsair VS 550w, CX 550w, CXM 550w would be about a half dozen steps upgrade in quality, far more dependable, and have proven protective circuitry that'll handle your pc just fine.
A little update. I upgraded to be quite BQT-L8-CM-530W psu. It runs very well and doesn't have any buzzing noise.