PSU wattage and all the confusion :(

[quysang219]

Hi guys,

 

My system is supported by a 400W PSU and consists of the following:

• Ryzen 5 3400G - TDP 65W
• Three case fans, two M.2 SSD and 2 RAMs on motherboard (Gigabyte Aorus Pro)
• NO VGA yet
• NO plan to use more storage (SSD&HDD)

I plan to buy the "GIGABYTE Radeon™ RX 570 Gaming 4G" (its source page recommends a 450W PSU)

https://www.gigabyte.com/vn/Graphics-Card/GV-RX570GAMING-4GD/sp#sp 

 

My question is:

• Do I really need to buy a better PSU before I add this VGA? Coz my power consumption seems so low
• If this PSU can actually support the VGA, how many SATA3 SSDs can I add before the power supply becomes insufficient?
• Do all 6+2 pin connector of all PSU provide the same amount of power? Or I need to check what PSU fits with what VGA first?

Many thanks in advance.

[Fasauceome]

1 minute ago, quysang219 said:

Do all 6+2 pin connector of all PSU provide the same amount of power?

Yes, 150 watts. For your reference, an RX 570 can also be run off only the 6 pin connector (if the need should arise) which delivers 75 watts.

 

As for power draw, that system will consume probably less than 300 watts at max load. I highly doubt an RX 570, A Ryzen 5 3400G, and a bunch of hard drives could give you trouble. The only concern is the quality of the power supply, since you always want to have a good PSU in a system you care about.

[Ben17]

Just now, Fasauceome said:

The only concern is the quality of the power supply, since you always want to have a good PSU in a system you care about.

agreed on that with the power supply

[bellabichon]

I can understand your confusion. I have no idea why the Gigabyte page says you need a 450W power supply for an RX 570. It's not a super power hungry card. Overall, your system actually seems to be pretty light on power usage. I would just make sure that your power supply can actually deliver 400W, and that it's from a reputable company. 

 

I can highly recommend the forum's power supply tier list if you want to see what people think about your PSU. 

[Duckson McQuack]

34 minutes ago, quysang219 said:

Hi guys,

 

My system is supported by a 400W PSU and consists of the following:

• Ryzen 5 3400G - TDP 65W
• Three case fans, two M.2 SSD and 2 RAMs on motherboard (Gigabyte Aorus Pro)
• NO VGA yet
• NO plan to use more storage (SSD&HDD)

I plan to buy the "GIGABYTE Radeon™ RX 570 Gaming 4G" (its source page recommends a 450W PSU)

https://www.gigabyte.com/vn/Graphics-Card/GV-RX570GAMING-4GD/sp#sp 

 

My question is:

• Do I really need to buy a better PSU before I add this VGA? Coz my power consumption seems so low
• If this PSU can actually support the VGA, how many SATA3 SSDs can I add before the power supply becomes insufficient?
• Do all 6+2 pin connector of all PSU provide the same amount of power? Or I need to check what PSU fits with what VGA first?

Many thanks in advance.

What model is the power supply? 
1: Make sure it's a passable unit with 80+ rating.
2: SSDs don't use that much wattage, you'll probably be fien.
3: Depends on how much your PSU can actually give, on lower end units it can be less than the advertised amount.

[quysang219]

1 hour ago, Fasauceome said:

Yes, 150 watts. For your reference, an RX 570 can also be run off only the 6 pin connector (if the need should arise) which delivers 75 watts.

 

As for power draw, that system will consume probably less than 300 watts at max load. I highly doubt an RX 570, A Ryzen 5 3400G, and a bunch of hard drives could give you trouble. The only concern is the quality of the power supply, since you always want to have a good PSU in a system you care about.

 

1 hour ago, Ben17 said:

agreed on that with the power supply

 

1 hour ago, bellabichon said:

I can understand your confusion. I have no idea why the Gigabyte page says you need a 450W power supply for an RX 570. It's not a super power hungry card. Overall, your system actually seems to be pretty light on power usage. I would just make sure that your power supply can actually deliver 400W, and that it's from a reputable company. 

 

I can highly recommend the forum's power supply tier list if you want to see what people think about your PSU. 

 

31 minutes ago, TeeKayTK said:

What model is the power supply? 
1: Make sure it's a passable unit with 80+ rating.
2: SSDs don't use that much wattage, you'll probably be fien.
3: Depends on how much your PSU can actually give, on lower end units it can be less than the advertised amount.

Thank you all so much for the quick help. My PSU can be trusted. It is a Xigmatek X-POWER II 450 with 400W real power (as I see in the table on the box). It is also of 80 Plus standard.

 

My confusion originated from a rather popular formula from youtube guides:

• Recommended PSU = CPU TDP + VGA TDP + 200W

I assume 200W was just a safe advice? In my case my CPU (65W) and VGA definitely won't exceed 300W. The remaining 100W could well be spent on 2-3 SSDs and fans right?

[Fasauceome]

10 minutes ago, quysang219 said:

My confusion originated from a rather popular formula from youtube guides:

• Recommended PSU = CPU TDP + VGA TDP + 200W

I assume 200W was just a safe advice? In my case my CPU (65W) and VGA definitely won't exceed 300W. The remaining 100W could well be spent on 2-3 SSDs and fans right?

YouTubers rarely give safe advice for power supplies. TDP is a thermal rating, not a power rating. 3 SSDs will use like 9 watts, and it takes dozens of fans to make a noticable difference in power draw.

[Guest]

5 minutes ago, quysang219 said:

My PSU can be trusted. It is a Xigmatek X-POWER II 450 with 400W real power (as I see in the table on the box). It is also of 80 Plus standard.

Why do you think it can be trusted?

 

Your 400W only has 325W available on the +12V.  It's an old group regulated design.  It's also 230V only, which means it has less robust parts on the primary side, incapable of handling the higher current of lower voltage mains.  Also, a cheap sleeve bearing fan.

 

It also does not actually have 80 PLUS.  It's not listed on the website.  Their ad copy simply says it's "80% Efficient Under Typical Loads" and the 80 PLUS logo they use is not the official 80 PLUS logo.

 

It's probably a Vietnam only SKU because Vietnam does not require any safety certifications and Xigmatek can't get sued for counterfeiting the 80 PLUS logo there.

[quysang219]

15 hours ago, jonnyGURU said:

Why do you think it can be trusted?

 

Your 400W only has 325W available on the +12V.  It's an old group regulated design.  It's also 230V only, which means it has less robust parts on the primary side, incapable of handling the higher current of lower voltage mains.  Also, a cheap sleeve bearing fan.

 

It also does not actually have 80 PLUS.  It's not listed on the website.  Their ad copy simply says it's "80% Efficient Under Typical Loads" and the 80 PLUS logo they use is not the official 80 PLUS logo.

 

It's probably a Vietnam only SKU because Vietnam does not require any safety certifications and Xigmatek can't get sued for counterfeiting the 80 PLUS logo there.

Hi Jon. I thought it could be trusted because Xigmatek looks like a rather big a popular brand here. I see a lot of its product and bought that PSU from one of the biggest PC component distributors in Vietnam.

After your comment I did also dropped by the store again and became officially lost in the world of PSU and electricity...

• Yes that PSU is Vietnam only https://www.xigmatek.com/product_detail.php?item=220
• Ouch that 80 Plus sign is fake? I never seen any other model...
• No each of the column in the PSU's wattage table does NOT represent one power cable? One tech guy brought me a 24 pin cable and started telling hey red means 12V yellow means -12V (something like that). I mean... wow...
• And the saddest part is NO everyone here and there say I should not add RX 570 to this PSU, even if I don't overclock at all.
• The website even says this VGA needs 150W https://www.amd.com/en/products/graphics/radeon-rx-570

I'm totally baffled. Then how should I calculate how big my PSU should be if the basic math CPU 65W VGA 150W is less than 400W does not work?

 

 

[Guest]

1 hour ago, quysang219 said:

Hi Jon. I thought it could be trusted because Xigmatek looks like a rather big a popular brand here. I see a lot of its product and bought that PSU from one of the biggest PC component distributors in Vietnam.

Probably because they're making a killing on profit margin.

 

1 hour ago, quysang219 said:

Ouch that 80 Plus sign is fake? I never seen any other model...

It's easy to just go to the 80 PLUS website and look up PSUs.  Either Google "80 PLUS" or go to https://www.plugloadsolutions.com/80PlusPowerSupplies.aspx

 

1 hour ago, quysang219 said:

No each of the column in the PSU's wattage table does NOT represent one power cable? One tech guy brought me a 24 pin cable and started telling hey red means 12V yellow means -12V (something like that). I mean... wow..

Not sure what you're trying to say here.

 

Each column on the PSU's label is the output for that voltage.  The +12V is the most important because that's what most of your components run on.  Look at better PSUs and you'll see this number is higher.

 

For example:  Your 400W has 325W on the +12V.  An EVGA W1 400W (which isn't much better of a PSU, but still better) has 360W on the +12V.

 

That's TOTAL.  That's not per connector or per rail or per wire... That's TOTAL.

 

1 hour ago, quysang219 said:

And the saddest part is NO everyone here and there say I should not add RX 570 to this PSU, even if I don't overclock at all.

I disagree.  RX 570 isn't a very power demanding graphics card.  And that PSU isn't a "bomb".  You can do a lot worse.  All I'm saying is that it's not a good PSU and you can do a lot better.  I just hope you didn't pay too much for it.

 

1 hour ago, quysang219 said:

400W does not work?

400W is enough power.

 

That's not the point anyone is making.  There's more to a PSU than the wattage label on it.  A PSU is more than a box of capacitors.

 

Like I said... you can do a lot worse.  Take this PSU for example: https://www.newegg.com/coolmax-i-400-400w/p/N82E16817159140

 

Only 300W on the +12V rail!  No PFC.  Doesn't even have a PCIe power connector!

 

I'd rather get kicked in the nuts the be forced to use that PSU.

 

So:  You're PSU will work fine.  It's just not a very good PSU.

[quysang219]

Thank you very much for your detailed info. Guess I must spend some time studying more about PSU and power first and see if this Xigmatek brand is really good (i see a lot of cases, psu, coolers, etc. from this brand so i blindly assumed they were good). For now I'll stick to that integrated Vega 11.