[SOLVED] Seasonic Focus PX 750 Platinum Upgrade?

Gunnerhero

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Sep 2, 2014
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Hi everyone,

I was lucky to get an Asus 3080 TUF and was thinking about upgrading my PSU to a Seasonic focus PX 750W platinum.

I currently have a Corsair CX-750 which is now approaching 7 years old... I personally have not had any issues with it so far but wondered what others have experienced with higher power graphics cards and if the Seasonic is any good?

My system currently:
Mobo: Asus ROG X470F
CPU: AMD 2700X
Graphics: Gigabyte 1060 6GB (Upgrading to Asus TUF 3080 OC 10GB)
Ram: Corsair Vengeance 2 X 8 GB
PSU: Corsair CX750

Any advice would be greatly appreciated,

Cheers,

Tom.
 

Barty1884

Titan
Moderator
The Seasonic PX is a quality unit - and would be a nice pairing with a 2700X + 3080.

The CX750 isn't very good (assuming green "CX" given the age?), and at ~7 years old, it's served it's time.
If memory serves, Corsair only warranted that unit for 5 years (?), so that tells a story.
Ultimately, it's been utilized to maybe 1/2 it's rated output, so would probably be fine in the current config indefinitely..... but given a 3080 can peak at ~400W power draw itself, I'd want a more quality unit backing it.

The PX750 is great quality - but whether it's the best 'value' will depend on your location and the price(s) you're seeing it at.
 
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Barty1884

Titan
Moderator
The Seasonic PX is a quality unit - and would be a nice pairing with a 2700X + 3080.

The CX750 isn't very good (assuming green "CX" given the age?), and at ~7 years old, it's served it's time.
If memory serves, Corsair only warranted that unit for 5 years (?), so that tells a story.
Ultimately, it's been utilized to maybe 1/2 it's rated output, so would probably be fine in the current config indefinitely..... but given a 3080 can peak at ~400W power draw itself, I'd want a more quality unit backing it.

The PX750 is great quality - but whether it's the best 'value' will depend on your location and the price(s) you're seeing it at.
 
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Gunnerhero

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Thanks both for the confirmation. I'm surprised how well the cx750 has done over the years but as you say it's probably only ever run about 50%. I better order the Seasonic before plugging in the new card, it is currently £139.99 which may be more than usual but I don't mind seeing as it has a 10 year warranty.
 
Hi everyone,

I was lucky to get an Asus 3080 TUF and was thinking about upgrading my PSU to a Seasonic focus PX 750W platinum.

I currently have a Corsair CX-750 which is now approaching 7 years old... I personally have not had any issues with it so far but wondered what others have experienced with higher power graphics cards and if the Seasonic is any good?

My system currently:
Mobo: Asus ROG X470F
CPU: AMD 2700X
Graphics: Gigabyte 1060 6GB (Upgrading to Asus TUF 3080 OC 10GB)
Ram: Corsair Vengeance 2 X 8 GB
PSU: Corsair CX750

Any advice would be greatly appreciated,

Cheers,

Tom.
The seasonic primes are among the top quality units among all available power supplies. They also have industry leading warranties. They have very high effici ncy and have a very low noise floor.

As an alternative to Sider Corsair RM series. I would also recommend 850 watts for long term stability if you plan to keep it a couple years.

As power supplies age, the capacitors degrade. This lowers overall output. My general rule of thumb is never run it continuously above 80% spec. Then account for at least a 20% max output decay. So that's 40% over spec I rate my supplies for. (That's not the correct math but the easy math to get a good estimate)

Today's CPU's and GPU's are extremely sensitive to voltage sag during transients. (Sudden power surges.). Capacitors on the end of power cables do help a tiny amount, but lower the efficiency of the PSU a little. Caps also lower dc voltage noise. Downside is they make the cables harder to work with sometimes. (Caps being built into the cable is a relatively new thing and only some brands do it.)
 

Juular

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Mar 14, 2020
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This lowers overall output.
It doesn't work like that.
So that's 40% over spec I rate my supplies for.
Oh, so instead of 750W for RTX3080 you suddenly need 1250W one ...
Capacitors do age, and i definitely would be concerned over the integrity of PSU you ran at 100% capacity 24/7 for 8 years straight even if it has 12 years warranty and it's a good PSU, but no, it's not a simple 'get 40% over nominal'. And most people wouldn't use a 750W PSU at 100% rated capacity for more than a few hours a day assuming they have a hardware for that in the first place. Companies selling PSUs aren't dumb and they wouldn't give you 10y+ warranty for a PSU that will lose it's capacity or fail on a majority of people, because they'll lose money and lose their reputation otherwise.
 
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It doesn't work like that.

Oh, so instead of 750W for RTX3080 you suddenly need 1250W one ...
Capacitors do age, and i definitely would be concerned over the integrity of PSU you ran at 100% capacity 24/7 for 8 years straight even if it has 12 years warranty and it's a good PSU, but no, it's not a simple 'get 40% over nominal'. And most people wouldn't use a 750W PSU at 100% rated capacity for more than a few hours a day assuming they have a hardware for that in the first place. Companies selling PSUs aren't dumb and they wouldn't give you 10y+ warranty for a PSU that will lose it's capacity or fail on a majority of people, because they'll lose money and lose their reputation otherwise.
A 750W unit might be able to deliver 600 Watts continuous 24/7 after a couple 7, 8 years if it's a good. The problem is paste caps do dry out over time. Especially in hot environments like a PSU. There's little you can do about this.

Steve from HardOCP did a followup on a 10 year old supply and he showed the graphs of how it decayed. And that was a quality high end brand.

Now if it's a really good brand like Corsair RM and Seasonic Prime, they will still get most of their rated output at full capacity after a few years. I have a great Corsair AX850 Gold from 8 years ago that is only now starting to show it's age. Anything over 700W continuous and it starts getting iffy on it's voltage output. I know I hooked a scope to it after my 7970 started failing about a year back.

If it's a piss pot poor brand, you might get 450Watts continuous with spikes to 600w and terrible noise.

And I never said 1250 W. NVIDIA recommends 850Watts and I understand why. If you want to run to the bleeding edge of it's rated capacity that's fine. Just realize two things:

  1. You'll wear it out quicker. The unit is working harder. It will get hotter. Heat kills electronics. As an engineer the rule of them is stay below 80% rated capacity if possible. If you look at component lifetime charts, they really start to fall off when you run them closer to capacity.
  2. You'll have to replace it sooner.
To me it's worth the extra $40 - $60 investment. I have to replace it less and I can transfer it to another computer in the future. That actually saves me money in the long term.
 
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Gunnerhero

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Sep 2, 2014
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Hi guys, I saw that this calculator was linked on one of the main PSU threads and it seems to think that my peak load will be 595W (probably be slightly more as I've seen the TUF OC is power hungry. This would be 13% below what the 750 is rated for. The most I would play during a day would be 4-5 hours at the weekend and I don't do anything else that would require full load.
 

Juular

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Mar 14, 2020
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NVIDIA recommends 850Watts and I understand why.
Because that's the power draw of Ampere with i9 10980XE at full load, not to mention quite high transients (because of high power draw overall) which trip some lower rated PSUs even though on average they should be enough, it has nothing to do with wattage overprovisioning.
I know I hooked a scope to it after my 7970 started failing about a year back.
Measurements without load mean nothing, either way, you were measuring voltage, not power capacity. Voltage might creep a bit but not due to aging capacitors but due to cables aging and being damaged over time. Aging capacitors also may introduce ripple (or rather not to filter it out properly), which again has nothing to do with capacity.
Steve from HardOCP did a followup on a 10 year old supply and he showed the graphs of how it decayed. And that was a quality high end brand.
I'll need a link for that as Google doesn't help but again, i'm pretty sure that graphs he was showing there are for voltages, not capacity.
Hi guys, I saw that this calculator was linked on one of the main PSU threads
PSU calculators are mostly incorrect or misleading but in this case you might actually be able to get away with 650W PSU.
 
Because that's the power draw of Ampere with i9 10980XE at full load, not to mention quite high transients (because of high power draw overall) which trip some lower rated PSUs even though on average they should be enough, it has nothing to do with wattage overprovisioning.

Measurements without load mean nothing, either way, you were measuring voltage, not power capacity. Voltage might creep a bit but not due to aging capacitors but due to cables aging and being damaged over time. Aging capacitors also may introduce ripple (or rather not to filter it out properly), which again has nothing to do with capacity.

I'll need a link for that as Google doesn't help but again, i'm pretty sure that graphs he was showing there are for voltages, not capacity.

PSU calculators are mostly incorrect or misleading but in this case you might actually be able to get away with 650W PSU.
The total draw of my system was 800 Watts at the wall. Assuming 88% efficiency that works out to ~700 Watts. No I didn't measure each line. But the noise level and voltage levels were getting much closer to ATX spec limite and it was much noisier than when it was released.

You are mostly correct there. Transients are extreme and not all power supplies handle them well. A number dip out, but having a larger power supply helps.

I wouldn't dare use a 650W, even a seasonic prime. 750W is okay, but only with a quality brand. 850W would be ideal for longevity.

I was talking power. And I measured voltage under load. I wanted to see if my power supply was going bad or the video card.

Steve did a measurement on transients, noise, % Deviation, and total power output before shut down.

Unfortunately HardOCP doesn't exist any more. He kind, of sort, of retired.

Side note:
Toms and Anand are one of the last real early pioneer websites. Toms and Anand have changed greatly to keep up. Many greats have risen and fallen in that time from sharkey, slash dot, blues, murc, and lastly hardocp.
 
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