Discussion PSU recommendations and power supply discussion thread - Tom's hardware

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Ma3s7ro

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Hx750 is 2 steps up from a RMx750, and a move from Gold to Platinum. Question is, are they new or old, gotta be careful of that, if they aren't black/silver they are old units.

this is the add:
https://www.olx.pt/anuncio/fonte-corsair-hx750-750w-80-plus-platinum-modular-IDBYFpK.html. Think its black ^^

I would NOT recommend a "used" PSU under any circumstances. You never know HOW it was used!
Yeah, i understand that, my feelings are the same, tough it would give me a hugely better psu (on paper at least), ence the temptation.

It seems both of them just have the Corsair warranty, no shop warranty available... What are your thoughts about the ones i put in previous post?

Seasonic Prime Ultra 550w and Super Flower Leadex III 550w? Are they as silent?
 
If you buy used hardware, and it fails on you within a few months, or doesn't work at all, I am going to laugh at you because you were already told twice, and now three times, that it's risky and it is my opinion a bad idea to purchase used hardware, especially power supplies, graphics cards and motherboards, from anybody you don't know well enough that you would feel comfortable inviting them to your mother's house for dinner during Thanksgiving or Christmas. That kind of "I trust this person". Otherwise, you are investing a significant portion of what you could put towards a new device with a warranty, into something somebody else has already said "this is too old or is not good enough for me anymore" about.

You CAN get lucky with used purchases. Many people do. However, MANY, MANY, .....MORE people, do not get lucky and end up throwing their money away. If you have money to throw away, then great. Otherwise, don't throw it away or even risk the possibility that you MIGHT be throwing it away, because you are probably not going to have any recourse once that money leaves your hands.
 
Power supplies weaken and wear with age, something not visable. Unless you have to, i woukdn't buy used.

I kind of disagree with graphics cards. Graphcs carde can fail, but id this isnt all that common compared to power supplies.

Plus, PSU deals are usually not great. You can get incredible deals on graphics card used.
 
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Ma3s7ro

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If you buy used hardware, and it fails on you within a few months, or doesn't work at all, I am going to laugh at you because you were already told twice, and now three times

Geez men, just asking, plus unless i'm mistaken i was advised by one to be carefull to check if it was new or old, and the other one to not make that decision.

Only asked since both PSU are 10/12 year warranty PSU's, i figured out they we're battle tanks and not easily messed up, plus they apparently had warranty's. Still i said i was unsure and asked for an opinion on the previous new ones, clearly showing my discomfort and seeking and alternative/better solution.

Saying you would laugh at someone for something going wrong is just plain salty, kinda of rude and imho unnecessary.

That beeing said, like i stated on previous post, the Super Flower Leadex III has good reviews and its supposed to be quieter than rm650x. From the techpowerup review the main complain i can't fully understand entirely, but from what i read it means the extra-protections it offers, in some scenarios, won't be as good.

https://www.techpowerup.com/review/super-flower-leadex-iii-650-w/7.html

I really appreciate the fact its rarely goes above 20ish db, but can't still figure out what the:
  • High OCP at +12V
  • Low PF readings with 230 V input
means.
 
Geez men, just asking,

And I'm just responding. Guess that looked more harsh than I intended it to, but honestly, what else can you do when you see thread after thread after thread of people who have been advised not to buy used hardware, but do, coming back to complain about how it has failed already? It's all you can really do. Nothing wrong with asking, I agree, but honestly it's a poor option unless it's the ONLY good option which is pretty rare. Anybody who really feels they NEED a capable system with reliable hardware can figure out a way to come up with that extra 20-30% they might save by buying used, even if it means they have to wait an extra week or two to do it. Not doing so, well, it puts you squarely in the "we told you so" category and it's hard not to laugh at people when they've gone ahead and went directly against the recommendations of people who've watched all this go on for quite a long time.
 

Karadjgne

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Since you mentioned it, there IS one thing about those nice, long, faith inspiring warranty. They don't apply to second owners. If one of those units fails a month from now, and you contact Corsair for a warranty fix/replacement, they'll ask for a purchase/sales slip to set the actual sale date or barring that the serial code to set the date of manufacture and place of sale.

The only place that those units would be covered from is an authorized reseller, and there's not that many. Any other sale, voids the warranty. So when they look up the serial and it's dated 3 years ago, and you owned it a month, not covered. If you lie and say you've had it 2 years, they'll ask the place of sale, and eh, not covered. If you lie and say you've had it 1 year, and the code says it was manufactured 6 months ago, they'll hang up on you, not covered. If you tell the truth, bought used online from a private party, not covered.

So anyway you look at it, you are on borrowed time, could be 1 day, 1 month, 1 year, 10 years. There's simply no way of knowing, just a hope and a prayer you got lucky.

Those 2 Corsair's are a couple of the better psus around, and if they are the new designed/revamped black/silver I wonder why they'd be up for sale in the first place since they'll power everything except a mining rig or 9900k/2080ti/rtx sli etc.
 

Aeacus

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Only asked since both PSU are 10/12 year warranty PSU's, i figured out they we're battle tanks and not easily messed up, plus they apparently had warranty's.
1st off, none of the Corsair PSUs have 12 years of warranty. Only Seasonic PRIME series has 12 years of warranty.

2nd, those used Corsair RM750x, HX750 you listed doesn't come with warranty. You'll only get warranty with brand new PSU, not with used PSU. Only way you can get warranty with used Corsair PSUs is when you buy Certified Refurbished PSU (link) and then, you'll only get 1 year of warranty, regardless which series PSU you buy.

And 3rd, if you pay peanuts - you will get monkeys. Meaning that cheaping out on the most important component inside the PC can have great consequences, since when PSU goes sky high, it has the magical ability to fry everything it's connected to.

It's up to you. Save €40 now just to hand out €1000+ once the used PSU fries your entire PC.

One thing i don't get. You clearly have enough money to buy €500 GPU (RTX 2070) but not enough to buy brand new €120 PSU. o_O You're joking, right?
 

Karadjgne

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Ppl have a God given right to do as they wish, and to (****) with consequences. I've had my i7-3770K pc for 7 years now, and the entire thing except psu and gpu was bought from eBay. $1800 pc for $600. When you figure the psu and gpu alone were $360, that's a pretty good deal for a fractal design R5 Window, Msi mpower Z77, i7-3770k, nzxt Kraken X61, Samsung 128Gb 840 Pro, Patriot Intel Extreme Masters 1866MHz 16Gb, WD Black 1Tb all for $240.

So I totally get trying to save a buck or 20.

But Caveat Emptor rules do apply. It's always a gamble buying used. Not to say you can't get a seriously good deal, especially with the build quality of the RMx and HX series, you'd stand a seriously good chance of never having anything but a great psu, but you do end up walking that tightrope with no safety net whatsoever.

I've been around pc's for over 40 years, and have yet to see a single post/review/complaint that either an RMx or HX blew up causing massive damage and taking out the entire pc. Those units just die, they don't die spectacularly. Not to say it hasn't happened, or couldn't happen, just that I've never seen nor heard of it happening.

I do believe that particular poster has been answered more than enough, he has plenty of info to think upon, and make a decision on, I don't see the need to get out the baseball bat too. 😉
 
Plus, you have a much better chance of at least getting hardware that works when you buy it in an already operational machine. Buying parts individually, you stand a MUCH higher chance of getting something that somebody returned because it had a problem or something somebody is trying to offload onto some poor schmuck because it has a problem, or just plain doesn't work. Guarantees aside, if they are a limited seller and don't give a crap about their seller rating, you are stuck with the item. It's not like Ebay is going to send the Ebay police to put them over their knee and spank them.
 
I have both bought and sold used hardware on ebay, fb marketplace, and just with friends.

I bought a used RX480 on eBay. The GPU, despite being sold as refurbished, arrived with error code 43. I was able to fix this easily and the card still works reliably after a repaste, but I still concider this a bit of a ripoff.

The best way to buy used hardware is when you trust the person well. You are less likely to get ripped off with defective products and you can often get better deals.

I recently bought a 250w PSU, 300w PSU, a PGA478 mobo, an LGA775 mobo, 2 old Pentiums, 2gb ddr+6gb ddr3 (6gb ddr3 is what i mainly wanted tbh), 2 coolers, 2 sony IDE optical drives for the price of a HP 120gb ssd ($15 value) and $20.

Not a great deal, but far better than anything online. Everything is working well, despite my friend telling me some of the ram was likely broken. Plus, no shipping cost.
 
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Mezoxin

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My experience with the used market specially these days is to avoid high end GPU's and PSU's , Thats because of minning , PSU's are not meant to take that kind of beating and abuse as i have seen some used EVGA G3 PSU's with their pci-e cables that for some reason became very stiff which is probably because of excessive 24/7 load on a single cable
Same for GPU's these minning rigs are mostly open air so some graphics cards cooling designs doesnt cover memory modules or VRMs which is bad if you are running the cards at full load 24/7
 

Ma3s7ro

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One thing i don't get. You clearly have enough money to buy €500 GPU (RTX 2070) but not enough to buy brand new €120 PSU. o_O You're joking, right?

Down the line, probably yes, right now, not really. And I'll wait untill good deals appear and even then, probably I'll go with a 3060. It takes a good month to save around 50€/70€ for meaningless/not family related expenses so it takes me around 9/10 months to save 500€ for this kind of investments, so every € counts. Tough I understand what you're saying, only brought it up because a hx is high-end PSU and could be almost indestructible. I wasn't asking about a 50€ PSU or even 70€ PSU second hand.

But Caveat Emptor rules do apply. It's always a gamble buying used. Not to say you can't get a seriously good deal, especially with the build quality of the RMx and HX series, you'd stand a seriously good chance of never having anything but a great psu, but you do end up walking that tightrope with no safety net whatsoever.

Yeah, true, so already decided to bite the bullet and buy a good one. Prefer not to take the chances on the PSU.

Think I'll go with the Leadex III 650w, silent and efficient and, well 40€ less than a rm650x with a current promotion I've encountered selling it for 79€ instead of the 99€ usual.

Still, if someone could explain the negatives"High OCP até +12V and Love PF readings with 230V input" I would appreciate it, since I've read the reviews but still sense I don't understand it. Always room to learn more.

Thank you all for the advices.
 
High OCP até +12V
OCP or over current protection prevents you from drawing too much power from your psu and damaging hardware. This also trips if there is a short circuit.

Having OCP set too high can cause the psu to ripple out of spec and possibly damage hardware if the PSU is overloaded.

PF, or i assume power factor is something i dont quite understand myself
 
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Mezoxin

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My understanding is all OCP found in single rail PSU's are not intended in protecting your equipment , think of it as your household Circuit breaker it protects the wires not the equipment connected to the plugs , When your PSU is shooting a constant 100 amps through an 18 guage cable due to a resistive load , you have more problems to worry about than voltage ripples over working capacitors
if you are worried about shorts from a resistive load that wont trigger the SCP you can make sure that during the build you dont pinch any wires specially when closing the side panels and inspect your connectors that they are free from cracks
 
So long as the PSU in question has the other protections that it should have, OCP itself and the fact that it is not specifically there to "protect your equipment" is almost irrelevant. So long as OPP, SCP and UVP are ALL present and working correctly, it almost doesn't matter what OCP or OTP do, but it's still obviously nice to have those things present anyhow.

Also, power supplies don't "shoot" anything, anywhere. Devices "eat" what they need and therefore create a demand which attemps to pull a specific amperage through the circuit. That can only happen if there is enough voltage present to push that amperage through the resistance of the circuit though. Remember, it takes 1 volt to push 1 amp through 1 ohm of resistance, in a DC circuit. I know I'm being semantic and pedantic, on that, but it's always worth it to use the proper nomenclature to avoid any confusion in conversations with somebody who may not know better. I guess in a manner of speaking you are at least partially correct when you say "shooting", but obviously that's not what's really going on. Ok, correct terminology rant over. Sorry.
 
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Ma3s7ro

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Devices "eat" what they need and therefore create a demand which attemps to pull a specific amperage through the circuit. That can only happen if there is enough voltage present to push that amperage through the resistance of the circuit though. Remember, it takes 1 volt to push 1 amp through 1 ohm of resistance, in a DC circuit. I know I'm being semantic and pedantic, on that, but it's always worth it to use the proper nomenclature to avoid any confusion in conversations with somebody who may not know better. I guess in a manner of speaking you are at least partially correct when you say "shooting", but obviously that's not what's really going on

I'll need a pair of hours to understand everything you said fully, but think I got the basics. Btw, being knowledgeable is different from pedantic, and you sir we're beeing the first. Proper use of terminology is indeed best to avoid confusion, especially when there are electrically noobish people like myself. Got my thumbs up on that.
 

Mezoxin

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So long as the PSU in question has the other protections that it should have, OCP itself and the fact that it is not specifically there to "protect your equipment" is almost irrelevant. So long as OPP, SCP and UVP are ALL present and working correctly, it almost doesn't matter what OCP or OTP do, but it's still obviously nice to have those things present anyhow.
Thank you for the refresh , I am always appreciative of using correct terminologies

I understand that the importance of OCP in single rail is diminished by other protection systems , but I think OCP at multirails when set to something like 40A would be the best candidate for preventing or limiting the consequences of something like this
https://forums.tomshardware.com/thr...x750-psu-which-cables-are-compatible.3551545/
 
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Possibly. It's a good idea for any quality unit to have ALL of those protections, and they should these days. If they don't, you have to weigh options and probabilities. Sometimes you have to leave something out to get something you need, if the budget or circumstances dictate it. Other times, people are just cheap af.
 
I really want reviews of that PSU and have been since it came out.

It looks good on paper.

DC-DC (it might only be partial from what i see)
80+ gold
5 year warranty
Jap main caps
Plenty of protections

I just have a hunch its based on an older platform for some reason.