Tips on Choosing a Power Supply

Hardware Hub PSU
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I’m looking for a power supply for a new mid-tier gaming build but I don’t know of many factors to choose between different PSUs.

I’ve only considered the wattage of my build, to make sure the PSU is at least gold rated, and that the manufacturer is reputable. Any other factors I should consider?

Regarding wattage, I’m planning on getting the ASUS PRIME GeForce RTX 5070 and the documentation recommends at least 750W and PC part picker says my build needs an estimated 436W.
I did some shopping and I’m thinking of going with either 1) CORSAIR RM750e (2025) or 2) MSI MAG A750GL but I’m having trouble choosing between the two because the specs have different verbiage.
For example, CORSAIR RM750e (2025) says it has 3 PCIe connectors but MSI MAG A750GL says it has 1 (450W) PCI-E 5.0 (16 pin) and 3 PCI-E (6+2 pin). Should I do further research on the corsair PSU to see the specific type of PCIe connectors?

I’m also planning on getting motherboard Gigabyte B650E Aorus Master. The specs of the board says it uses 1 x 24 ATX pin and 2 x 8 ATX 12 V pin but I don’t see that mentioned on the specs for either PSU. The RTX 5070 uses 1 x 16-pin which is mentioned on the MIS PSU as 1 (450W) PCI-E 5.0. No mention of 1 x 16-pin on the corsair.

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I’d go for the Corsair. They have very good warranty and RMA, I’ve broken the tabs off a bunch of cables and they’re always quick to send me a replacement, even on power supplies I’ve been using for years.

Corsair doesn’t seem to have updated their RM750e page for the 2025 version, they list that it comes with two 2x8-pin and one 1x8-pin, for five 8-pin total, when actually it comes with one 2x8-pin, one 1x8-pin, and one 12VHPWR, for three 8-pin and one 12VHPWR total. The MSI seems to have the same cables, so in that case it comes to brand credibility, where I’d say Corsair has the better reputation.

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If I had to choose one of them I’d choose the MSI PSU because it was made by a more reputable manufacturer than that particular Corsair PSU. Corsair has gathered alot of goodwill by selling Great Wall PSUs, but the RM750e is made by HEC which isn’t exactly the highest regarded PSU manufacturer.

A Corsair RM750x is probably a better chose, it at least shares the same manufacture r as the MSI PSU; A PSU made by Great Wall would be even more preferable.

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Wattage / Efficiency / Layout
Both are 750W / Gold / Similar-Same footprint + Wiring capacities

One obvious area of differentiation, would be MSi is working a native 12V 2x6 wire

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I got the Super Flower SE addition, from what I understand non-SE additions are loud. Gold with a 10 year warranty.

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At minimum I look at the Cybenetics report for any supply under consideration and, there’s one’s available, check its HWBusters review for notes of issues. You can see at a glance the A750GL’s stupid loud, so if that matters at all the RM750e’s the obvious choice.

5070’s borderline for 12V-2x6, so I’d avoid a 12+4 connection at the PSU. I’m not aware of MSI making 12+4 ← 2x8 cables and, even if they do, the A750GL’s only 3x8-pin.

750-850 differences can be quite small (literally only one part changes between some models) and price differences tend to be minor (and sometimes invert) so I wouldn’t exclude 850s.

Usually lots of errors there so it’s often a good exercise to go through its calculations and fix the bugs. Might not affect PSU rating but, if noise or keeping the PSU in fan stop are important, may influence supply selection.

RMe is Corsair’s cost down line, so I’d consider at least also RMx and RMx Shift. I don’t see any reason to differentiate between HEC, Channel Well, or Great Wall here. There are OEM level distinctions but those three are all pretty fine, so it’s more about what the companies contracting them have asked for in platform customizations.

Corsair’s pretty clear about keeping a close eye on what their subcons are doing so, statistically speaking, other companies are likely to be more hands off. That MSI is shipping the A750GL’s fan profile suggests they don’t care, so can’t say I’m inclined to be optimistic there.

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Look at Corsair’s website. Just by the picture you can see it has a native 12V-2x6 connector.

Corsair is a pretty safe choice these days and that’s probably what I would pick unless the MSI was cheaper and I was strapped for cash. I don’t think the MSI supply is bad, it just isn’t my first choice.

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Thanks. So there is a distinction between the brand name like Corsair and who actually makes the PSU like Great Wall? How do I determine who actually makes the PSU when shopping?

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You can’t without a lot of digging as OEMs are essentially a “quiet third-party”. This means, for this specific subject, the “manufacturer” or OEM, physically makes the product and this can be an in-house design or a third-party design that they tweak OR they go with the OEM model and “rebrand” it. Some reviewers that have contacts or that are very familiar with certain power supplies may be able to make a faster assessment, but for an end-user, it’s work.

No one mentioned alternatives like SeaSonic, EVGA and be quiet!, so I will.

As far as wattage goes, it’s easiest to go by the video card’s recommendation and add 100-200 watts to that just to cover your fans, RGB, storage, more importantly incremental upgrades, etc.

That’s actually not an easy distinction just by looking at the connector. Unless 12V-2x6 is explicitly advertised, it could just be the old connector. They’re backwards compatible, so just looking at the connector says nothing.

Edit: Warranty is something to consider, too, and this WILL differ by vendor and possibly by region.

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Yes, only a handful of PSU brands actually manufacture their own PSUs like Seasonic and FSP. I don’t mean to imply that manufacturer and brand name matching means that a PSU is high quality though.

I echo @lemma’s suggestion at checking hwbusters site, it will tell you who manufactures the PSU in question along with the best tests of any website reviewing PSUs imo.

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I’m using manufacturer as a proxy for quality, which isn’t a perfect metric… but I trust using it more than the brand name since it’s the manufactures that tend to have the best power engineers that can actually make a quality product over brand name’s on staff engineers which do not understand PSU design as well as the people actually designing and making them.

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Thanks. I think I’m going to go with a higher tier corsair after seeing the comments. Can you elaborate on what you mean by 5070’s borderline for 12V-2x6? I looked at the required connector for the 5070 read that it requires a 12V-2x6 connector. Is that a newer version of 12+4?

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Yes. 12V-2x6 is the updated 12+4 connector.

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Wasn’t the point of 12V-2x6 that it used the same cables? The new connector would only be present on the GPU, so it doesn’t matter which spec is printed on the PSU.

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OEM information’s pretty widely available, including in Cybenetics reports.

Seasonic switched to direct sales years ago because they were bad enough their OEM contracts dried up. But somehow they still have good rep with a lot of forum posters.

It’s my understanding ASRock acquired EVGA’s PSU division. Some of the fan control’s wonky but the Phantom Gaming and Taichi have remote 12+4 OTP, which is perhaps the single best mitigation available short of Nvidia actually doing something about 12+4. Big jump from RM750e to TC-1300T, though.

be quiet!'s supplies are pretty mixed, so are best taken on a model by model basis. My experience is there’s usually a better option, though occasionally Dark and Straight Power get tempting pricing here. Also the rail and Y cable arrangement’s unusual, so a bit of extra planning’s wise if going be quiet!.

As @Susanna’s brought up, the updated header’s only half of a 12+4 connection.

While PCIe 5.1 does not change the 12VHWPR plug dimensions, cables are relabeled as 12V-2x6 because people commonly assume 12VHWPR cables need replacing too. The relabeling’s actually a PCIe spec violation but it’s not like PCI-SIG’s been showing a lot ability to think things through here. The header change is the sense pin retraction, so you can tell by looking.

Since we’re on the topic, also ATX 3.1 is a downgrade from ATX 3.0. So if a supply passes ATX 3.0 it passes 3.1. But since people assume newer version better ATX 3.0 supplies have got their specs and boxes changed to say 3.1.

12+4 headers are present on many PSUs. Since people assume newer is better a corollary is PSUs without a 12+4 connector are perceived as bad. So supplies with 12+4 have a way of selling better even though 2x8 → 12+4 is better engineering.

I don’t know of any PSU released with a 12+4 header within the 12VHPWR timeframe, so probably they’re basically all 12V-2x6, but if you look hard enough you might be able to find one that’s not a prototype or engineering sample.

Measurements of GPU-cable-PSU assemblies show Nvidia’s 600 W claim is broken by design. Doesn’t help PCIe 5.0/5.1’s both internally inconsistent and incompletely margined. But 12V-2x6 provides Nvidia a pretext to pretend 4080, 4090, 5070 Ti, 5080, and 5090 aren’t safety margin regressions from 8-pin power.

For 12V-2x6 to have the same safety margin as 8-pin and EPS it’d be rated at 275-300 W, depending on hardware details. However, 12+4’s smaller size means that’s likely optimistic due to higher power density and reliance on ground return primarily through the slot. So data presently available suggests more for ~250 W. It’s possible to construct reasonable arguments down to ~200 W or so. IMO 200’s pretty conservative on current data but the more 12+4 gets looked at the worse it gets. So ¯\_(ツ)_/¯.

A 5070 pulls ~250 W through 12+4. If dGPUs weren’t so hard to get I’ve suggested returning the Prime for a 9070 upthread.

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Didn’t know that. Mine has been fine, but I won’t dismiss the concern at all, because that definitely is one.

Fair.

Also fair.

“I can only speak from personal experience” should be everyone’s signature.

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From what I understand, a good part of it was Seasonic being difficult to work with. The electrical side of their supplies can be good at times and they still do some OEM and IIRC relabeling business. Fan control tends to be aggressively weird, though, and if you want a company that’ll own up to issues and be proactive about fixing them that doesn’t seem to be their thing. For either major customers or individuals buying directly. I’ve also noticed quite a few instances what’s either incredibly sloppy editing on their website or just plain disinformation.

I’ve never bought a Seasonic as every time I’ve run a parts selection there’s been something better. If you don’t care about noise and want tight regulation (even though there’s no evidence it makes a difference from other supplies also exceeding ATX requirements by a wide margin) then maybe there’d be a fit.

In particular, Asus pushed Seasonic to some pretty nice results with Thor and Loki. But you’re probably not going to buy those unless you want to pay ROG brand tax and happen to live somewhere with fairly good immunity to poor RMA and repair behavior.

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+1

I heard this from microcenter employees, so take with a grain of salt, but they mentioned MSI picked up a large portion of the ex-EVGA PSU engineers.

I’m a fan of the Loki PSUs, they make the highest power SFX PSU available, they are great wall.

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They’re not SFX, they’re SFX-L. It might seem like nitpicking, but in SFF those centimetres make a huge difference.

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That is very true. Also true they (SFX vs SFX-L) don’t necessarily fit in the same cases.

I never really thought about it before, but I just realized there isn’t really any length specification for ATX PSUs that is consistently followed.

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So far as I know the flexibility for ATX supplies to vary in length based on how much internal space they need is an intentional feature. Also it’s similar to fans in that everybody pretty much sticks to a few standard sizes. The PSUs I can think of offhand are mostly 160, 180, or 200 mm with occasional 140s and 150s. IIRC there’s a few 130s. Maybe somebody’s done 220 but I can’t think of any.

Edit: woo, a table. There’s been an uptick in 130 and 160 mm fans the past couple years, though.

fan size list, mm PSU length list, mm
80 130
92 140
120 150
140 160
180 180
200 200
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