[SOLVED] Importance of the 4-Pin Sense in the PSU

[Rameyukk]

Hi Everyone, I have a quick question on the importance of the 4-pin sense in the PSU.
Here's a bit of a background:

I've previously purchased and used my Silverstone SX800-LTI PSU on a small form factor.
But due to thermal issues, I had to move all the components to a slightly bigger case.

The included cable has a 300 mm 20+4-pin ATX connector that I hooked all 24-pin onto the motherboard on one end, while the other end comes out as 24-pin ATX cable + 4-pin Sense cable that I plugged into the PSU on both 24-pin MB and 4-pin sense connector respectively.

My problem, the 24-pin and the 8-pin EPS cables that was included with the PSU is now too short to reach the ports when moved to the new case.

So I got myself longer cables, the Silverstone PP05-L that should reach everything in my new case.
But the new longer cables only have full 20+4-pin ATX connector on one end, and 24-pin ATX on the other end. There's no 4-pin sense cable that was there.

My question is, is the 4-pin sense cable required for the operations of the PSU and motherboard? If so, why isn't the 4-pin sense cable a standard on all the 24-pin ATX cables? especially since the cables are coming from the exact same manufacturer as the PSU, and how do I solve the problem of a complete cable that's too short, but I have a longer cable that doesn't have the Sense connectors in place?

I'm using an MSI Z390I mini-ITX motherboard.

Any help would be appreciated.

 

[Vic 40]

Is that cable above the original one?

Seems to have 24pins at both ends which make sense. The side which is one solid connector should probably go into the psu where the one with a seperate 4 pin piece would be used to power the motherboard. It would have the seperate 4pin piece for compatibility with older motherboards that only use a 20 pin connector.

 

[Rameyukk]

Is that cable above the original one?

Seems to have 24pins at both ends which make sense. The side which is one solid connector should probably go into the psu where the one with a seperate 4 pin piece would be used to power the motherboard. It would have the seperate 4pin piece for compatibility with older motherboards that only use a 20 pin connector.

Sorry, the image above is not the original cable. It's the longer cable that I purchased to reach the motherboard from the PSU in the new case.

Below are the cables from the original PSU:

Note that the 24-Pin PSU have that extra 4-pin on the left side, while the other end on the right side is a 20+4pin connectors. I plugged the 20+4 pin on my motherboard, while the 24-pin goes to ATX socket, while the remaining 4-pin goes to the Sense socket in the PSU.

I've went ahead with my build to just use the 24-pin directly between my PSU and motherboard using the new cable. It seems to work just fine, but I'm worried what it would do in the long-run if there is any negative impact of skipping those 4-pin sense socket in the PSU.

Based on this review of the PSU: https://smallformfactor.net/reviews/powersupplies/silverstone-sx800-lti-review/
they did say that:

"Since this is the same base platform that the PE-750 uses, the SX800-LTI also features the same 4-pin connector split off from the 24-pin for voltage sensing. This connector is not strictly required though and the unit will operate without it, so existing 24-pin cables made for other Silverstone modular units (like the SilverStone PP05-E kit or custom CableMod cables) will work, albeit with slightly worse voltage regulation as a result."

Slightly worse voltage regulation? Is that going to impact the lifetime of my motherboard? Why is this cable form not standard coming from the same manufacturer? The fact that they didn't include a cover cap on the socket makes it exposed to dust etc.

 

[Vic 40]

Slightly worse voltage regulation? Is that going to impact the lifetime of my motherboard? Why is this cable form not standard coming from the same manufacturer? The fact that they didn't include a cover cap on the socket makes it exposed to dust etc.

No it will not impact motherboards life or other components. Just means that Voltage regulation (and think only +12V) will be abit looser, so instead of being between 12.2V<->12.1V might it be between 12.2V<->12.0V., think something like that. The latter is still fine.

No cover for dust will be fine, just clean your pc once in a while.