[SOLVED] Do I need to change from Power supply

[millibrixx]

I want to have a i9-9900K With the MSI z390 gaming plus and a Power supply from Corsair CX650M bronze is it fine to use that power supply should I need to look for a power supply that is diffrent or isnt it so hard to look for a power supply

 

[Metal Messiah.]

What about your GPU upgrade ? Which video card are you going to use on that setup ? This will also be a deciding factor, regarding the Wattage value. Anyways, that CXM model is an average unit. Not the very best Corsair sells, but it does the job ( Is it one of the older "Green unit" variants, or a "Grey unit" ?)

 

[millibrixx]

What about your GPU upgrade ? Which video card are you going to use on that setup ? This will also be a deciding factor, regarding the Wattage value. Anyways, that CXM model is an average unit. Not the very best Corsair sells, but it does the job ( Is it one of the older "Green unit" variants, or a "Grey unit" ?)

I use a 1060 6G gigabyte and the power supply self is black but there is indeed some Grey yes

 

[Karadjgne]

CXM 650w is squeeking the low end for that cpu. The 9900k is brutal in its demands. You are looking at 200-250w just for cpu, 120w for gpu and another 100w for the rest of the pc. That's 450w+ before any OC. If you ever bump up to a more powerful gpu, figure on adding @120w more for the gpu and 50-100w for OC. Most will recommend a very good quality 750w or 850w, Seasonic Focus, Corsair RMx, Evga G2 etc.

The kicker is that many budget psus do not have the multiple EPS connectors that is pretty much required by that cpu for any OC or locked core speeds.

 

[TJ Hooker]

You're fine with your current PSU.

 

[jankerson]

I want to have a i9-9900K With the MSI z390 gaming plus and a Power supply from Corsair CX650M bronze is it fine to use that power supply should I need to look for a power supply that is diffrent or isnt it so hard to look for a power supply

I would recommend something better than that, that's a low end PSU, not really suited for that system.

Something like the following:

Seasonic Focus Plus
EVGA G2
Corsair RMX

750W would be recommended due to the cabling options, having 2X EPS connections for the MB.

 

[millibrixx]

I would recommend something better than that, that's a low end PSU, not really suited for that system.

Something like the following:

Seasonic Focus Plus
EVGA G2
Corsair RMX

750W would be recommended due to the cabling options, having 2X EPS connections for the MB.

Maybe it sounds stupid but what are the EPS connections what do they do

 

[Metal Messiah.]

The EPS 12V 8PIN ATX 12V connector connects to the motherboard EPS 12V socket. And it provides additional power to the CPU.

8 pin is rated to safely deliver twice as much power as 4 pin for CPU power connectors. There aren't any modern CPUs without significant overclocking where a 4 pin is not good enough, but it's also not difficult to find decent motherboards and PSUs that have 8 pins anyway.

The 4 and 8 pin connectors and sockets are inter-compatible. IE an 8 pin slot can have a 4 pin connector and an 8 pin connector can have half of its connectors plugged in and the other half not plugged in for a 4 pin slot. It is best to simply make sure that you have enough power for the CPU. If it uses say 130W or more, then it's best to use an 8 pin slot and an 8 pin connector. Any less for CPU power consumption and it doesn't really matter.

 

[Karadjgne]

The 20+4 powers most of the mobo, but only has 2x 12v power leads, the rest being the minor rails, grounds etc. If you figure those 2x 12vDC leads are only good for a maximum of 60w each, and a cpu is somewhere around 75w or more, the gpu slots are 75w etc. Then there's a shortage of 12v to the motherboard in general. This is made up for by the EPS (extra power supply lol). A 4pin can add an extra 120w, an 8pin can add an extra 240w max. The i9-9900k can pull 200-250w in stock values, it scales up cores according to voltage (like a set of stairs) so not having suffient EPS supply means the cpu gets short changed and won't perform as it's expected to. Most mobo's designed with the i9-9900k as a primary consideration will have 1x 8pin EPS and a 4pin minimum or 6pin or second 8pin as well.

Your standard ATX psu only has a single 4+4pin EPS, it's not until you get to the 750w+ range that there's sufficient power to handle not only the i9-9900k but also the high end gpus that usually accompany such a powerful cpu. Very rare to see someone spend over $1000 on a mobo and cpu and slap in a gtx1050ti.

 

[TJ Hooker]

The two 12V pins on a 24 pin connector can supply up to 144W (6A per pin). An EPS connector with four 12V pins can supply up to 336W (7A per pin). With 480W total power available on the 12V rail for CPU + GPU, you're fine with a single EPS connector for anything short of extreme overclocking.

https://www.molex.com/pdm_docs/ps/PS-5556-001-001.pdf
http://www.playtool.com/pages/psuconnectors/connectors.html

 

[jankerson]

The 20+4 powers most of the mobo, but only has 2x 12v power leads, the rest being the minor rails, grounds etc. If you figure those 2x 12vDC leads are only good for a maximum of 60w each, and a cpu is somewhere around 75w or more, the gpu slots are 75w etc. Then there's a shortage of 12v to the motherboard in general. This is made up for by the EPS (extra power supply lol). A 4pin can add an extra 120w, an 8pin can add an extra 240w max. The i9-9900k can pull 200-250w in stock values, it scales up cores according to voltage (like a set of stairs) so not having suffient EPS supply means the cpu gets short changed and won't perform as it's expected to. Most mobo's designed with the i9-9900k as a primary consideration will have 1x 8pin EPS and a 4pin minimum or 6pin or second 8pin as well.

Your standard ATX psu only has a single 4+4pin EPS, it's not until you get to the 750w+ range that there's sufficient power to handle not only the i9-9900k but also the high end gpus that usually accompany such a powerful cpu. Very rare to see someone spend over $1000 on a mobo and cpu and slap in a gtx1050ti.

Exactly.

Most of them are 8+4 pin with the higher end boards being 8+8 pin.

Not sure were people are getting you don't need to plug in the 2nd PSU connection, however it is basically some reviewers cottling the budget buyers that won't spend the money on the proper PSU's.

Very few 650W and under PSU's have 2X EPS connections so that pretty much does away with any budget model PSU's some like to recommend. Only a few higher end 650W PSU have 2X EPS connections.

So much misinformation around these days, it's really said.

It's like they are telling people the 2nd EPS connection is there just for looks.

 

[TJ Hooker]

Even if a single EPS connector was insufficient in the OP's case (it's not), their motherboard only has one EPS connector (and no 4 pin ATX connectors).

 

[jankerson]

Even if a single EPS connector was insufficient in the OP's case (it's not), their motherboard only has one EPS connector (and no 4 pin ATX connectors).

Yeah it's a low end Z390 MB that really can't handle the 9900K in the 1st place, very poor, crap VRMS.

They will figure that out however when it doesn't last very long due to the VRMS overheating and will burn up eventually. The VRMS don't even have adequate cooling as they don't even have heatsinks on part of them.

Shouldn't be running anything more than a i5 on that MB.

View: https://www.youtube.com/watch?v=cZcqw-K1drY&t=829s

 

[Karadjgne]

Since when were pins rated at 6-7A? The wiring, sure, it's 18ga, but the pins themselves will only handle upto 5A. You try sticking 7A through any pin and you'll melt the connector.

 

[TJ Hooker]

Since when were pins rated at 6-7A? The wiring, sure, it's 18ga, but the pins themselves will only handle upto 5A. You try sticking 7A through any pin and you'll melt the connector.

I already linked to the molex mini fit jr. connector spec page. Feel free to check it yourself.

 

[Karadjgne]

I did.

A power or signal interconnect system rated up to 5.0A per circuit with standard brass terminals. Tough Nylon housings and robust terminal design create a durable, long lasting product. The Standard .062" products are reliable, economical and offer high value in features and price. These products are an excellent choice for power or signal interconnect applications.

You links cover wire sizes, not pins, wire length has nothing to do with the pin itself.
But according to molex, the mini-fit Jr/plus can carry 9A/13A, but uses a larger pin to do so.
https://www.molex.com/molex/products/group?key=power_connectors&channel=PRODUCTS

Your link says the EPS is unofficially good for 336w, that's 7A per wire/pin, yet molex says (if it's indeed a mini-fit Jr) then it's good for 9A per wire, which would be 384w.

Also, your links also specify deratement according to multiple factors, such as fitment, actual wire length, wear, ambient temps, board temps etc.

Personally I'd trust in the 5A rating for a standard pin, more than a varied statement that was last updated in 2008.

 

[TJ Hooker]

I don't see the text you quoted anywhere in any of my or your links, where are you seeing that?

Edit: Ah, it seems you just found the description for some random pin that Molex offers. Here are the parts that are actually used for 12V power delivery, according to Intel's ATX12V spec:

+12 V Power Connector
Connector: Molex 0039012040 or equivalent.
Contact: Molex 44476-1112 (HCS) or equivalent (Mating motherboard connector is Molex 39-29-9042 or equivalent)

chrome-extension://oemmndcbldboiebfnladdacbdfmadadm/https://www.intel.com/content/dam/www/public/us/en/documents/design-guides/resellers-power-supply-design-guide-changes.pdf

The contacts to be used are from the Mini Fit Plus HCS (high current system) family (e.g. Molex 44476-1112). All of these contacts are rated for 9A or higher. If using 18 AWG wire and it's part of a 2 by 4 (total 8) pin connector, it's de-rated to 8A.

The connector is rated for 13A. But when using 18 AWG wire and part of a 8 pin connector, it's de-rated to 8.5A.

The motherboard header listed in the spec is rated for 13A. But when using 18 AWG wire and part of a 8 pin connector, it's de-rated to 7A. So it lines up with the unofficial max ratings listed in one of my earlier links. And yes, there is a note about additional de-rating based on other factors, e.g. PCB traces, so you may not want to run it right at that 7A limit. But I think it makes more sense to state the rated numbers rather than some number you seem to have pulled out of thin air (i.e. 5A).