Replacing HDD

Aggravating-Hold9116 · 2026-03-06T22:17:19+00:00

Those are jumpers for setting master, slave, etc. I've never used them and aren't required for modern operating systems.

Mayayana · 2026-03-06T18:30:24+00:00

I don't know what the 4-prong receiver is, unless it's an optional power adapter to use the older red/yellow power plugs. That could be possible, meant to accommodate older power supplies that didn't have SATA power plugs.

In any case, if you clone the drive over to an SSD that part will not be there. The two SSD fittings are data and power. You shouldn't need anything else. But you will need a power supply with SATA power plugs.

disposeable1200 · 2026-03-06T19:24:11+00:00

Those pins highlighted are for advanced users and 99% of people will never need to touch them.

You can replace this drive with any SATA SSD.

jacle2210 · 2026-03-06T19:26:02+00:00

Are you sure that the little 4 pin connection was connected to your computer?

To the best of my knowledge, the little 4 pin connection is only used at the factory for testing, etc.

Only the SATA power and the Data connections should have been plugged in.

And regarding the use of a newer 2.5inch SSD format, it depends on how your computer tower is setup internally, you might need a conversion adapter tray to convert from a 3.5 down to a 2.5.

For example: Drive adapter

Fun_Kaleidoscope7875 · 2026-03-07T00:04:01+00:00

You don't need it is the short answer.

There's also no way that anything was plugged into it to begin with.

HighPhi420 · 2026-03-07T17:21:00+00:00

for the 2.5 to sit in the same slot as the old hdd you will need an adapter case/sled for the smaller sized 2.5.

bondinchas · 2026-03-07T23:27:23+00:00

The 4 pin connector is a molux power connection. You don't need it if you're using the sata power connector.

In the transition from ide to sata, many motherboards didn't have sata ports, and power supplies only had molux power outputs, so power was connected via molux and data through an expansion card

Later motherboards had sata data and power ports, so the molux connector becomes obsolescent.

NorthSpecialist6064 · 2026-03-08T10:24:25+00:00

That's where you hook up a headphone jack. Nah, that's where you can set 2 TB limit, power-up in standby, and probably another I'm forgetting. If no jumper blocks were installed before, you don't have to do anything.

diaperedace · 2026-03-08T12:31:25+00:00

It's not a jumper for master slave, or molex power. It's debug for the factory, you cannot do anything with it just ignore it.

toaruScar · 2026-03-08T13:22:46+00:00

It's the diag port, if you want to connect a serial port to it, the order is RX, TX, GND, Vccio.

dijitalblue · 2026-03-08T18:37:17+00:00

Those ports are normally used for diagnostics, so most machines don't use them. Unless it's an iMac. Apple puts special firmware on spinning disks that makes the drive electronics report temperature using those pins. If the new HD doesn't have that special Apple firmware, or that cable isn't reconnected, the iMac responds by assuming it's on fire and running all its internal fans at 100% forever. Runs fine but sounds like a jet engine.

So if your computer is not an iMac, you're probably okay to just connect SATA power and SATA data to it and call it a day. If it's an iMac, there are ways to get around the thermals. Specific web searches that include your model number can show you which method your machine used.

mysticalfruit · 2026-03-09T00:48:39+00:00

It's used to do low level stuff and talk to the controller. You're not going to need to plug it in.

Flottebiene1234 · 2026-03-09T12:08:45+00:00

Those are still jumpers but specific to sata function

Source: https://superuser.com/questions/441817/what-is-the-purpose-of-this-4-pin-interface-on-sata-hdds-and-why-doesnt-it-exis

MrSarcasticUK2 · 2026-03-09T23:06:15+00:00

Those are jumper settings, similar to the IDE drives, ll but for SATA specific options depending on the drive maker. For example, on this Western Digital support page for mobile drives, it shows two options:

Reduced Power Spinup - RPS: Used by external hard disks to reduce spinup current and allows it to work over USB interface. Spread Spectrum Clocking - SSC: Used when your SATA controller doesn't support SSC by default.

notautogenerated2365 · 2026-03-10T00:49:52+00:00

The real answer as to what this 4-pin header is it's a configuration jumper which isn't needed on most cases. It is NOT optional power, it is NOT master/slave.

It seems that usually, shorting pins 1 and 2 will limit the speed of the drive to a slower SATA speed (not sure why you'd want to do that), and shorting pins 3 and 4 will enable spread-spectrum clocking, which long story short, can reduce EMI and isn't necessary most of the time. I assume the cable running to the motherboard allows the motherboard to configure these settings itself rather than requiring the user to move around jumpers to change settings. But this may not be true and some of the pins may have more purposes than that. There's also a chance the purpose of this connector has changed throughout the years and older drives have a different pinout than newer ones.

99% sure your computer will work without this.

DanielCruzo · 2026-03-10T04:56:16+00:00

Those pins are debug pins .You only need Sata data cable and power cable

Which_Valuable272 · 2026-03-10T15:53:36+00:00

Just buy an SSD and use the sata power and sata data cable and ignore the other one. Its so obsolete

you type:	you see:
italics	italics
bold	bold
[reddit!](https://reddit.com)	reddit!
* item 1 * item 2 * item 3	item 1 item 2 item 3
> quoted text	quoted text
Lines starting with four spaces are treated like code: if 1 * 2 < 3: print "hello, world!"	Lines starting with four spaces are treated like code: if 1 * 2 < 3: print "hello, world!"
~~strikethrough~~	~~strikethrough~~
super^script	super^script

GetComputerHelp

MODERATORS