When swapping the 850w OEM Dell PSU, do you need to replace the cables(wires) from the removed PSU?

My OEM 850w PSU appears to be modular, and I was curious if you could just remove the PSU, and leave the OEM cables in place (plug them back into the newly installed PSU)?

Are they specific to the PSU itself, or universal?

Modular PSU cables are specific to the PSU itself. Please do not mix PSU and cables.

So if these are normally 450 watts, do you really need an 850 watt to replace it?  The reason I ask is, my computer has been hanging up lately when I hear slave drives revving up.  I figure this is because the power supply is getting weak.  I want to replace it but I don't want to spend the money on an 850 since I'll probably replace this pc in another year.  Would a 650 watt not be sufficient enough? 

@Jombiss :

So if these are normally 450 watts, do you really need an 850 watt to replace it?  The reason I ask is, my computer has been hanging up lately when I hear slave drives revving up.  I figure this is because the power supply is getting weak.  I want to replace it but I don't want to spend the money on an 850 since I'll probably replace this pc in another year.  Would a 650 watt not be sufficient enough? 

Is your computer an XPS 8930? What config? The term "slave drive" has not been used since the IDE days when we played around with jumpers on the hard drive.

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@Jombiss wrote:

1. So if these are normally 450 watts, do you really need an 850 watt to replace it? 

2. The reason I ask is, my computer has been hanging up lately when I hear slave drives revving up.  I figure this is because the power supply is getting weak. 

3. I want to replace it but I don't want to spend the money on an 850 since I'll probably replace this pc in another year.  Would a 650 watt not be sufficient enough? 

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1. You should always over-size the Power-Supply. Then hopefully, while you are running the system at Max all hot-and-heavy ... the PS can still just be running at 50-60% utilization (cooler, more stable voltages).

2. Unknown

3. Well, if $50-$75 extra is a lot of money to you ... maybe you should just save your money and hope it does not explode before you are finished with it all. 

Does the PSU come with the needed wires or do you need to buy them separately? If so would posting a link be possible?

@Kreptic    Does the PSU come with the needed wires or do you need to buy them separately? 

The Seasonic Focus fully modular PSU includes more power cables than you could ever use. You will need to purchase the adapter linked below for the optical drive.

SATA 15-pin to 6-pin Slimline Adapter 

Hi i have a dell xps 8930 as well but mine has an i7-8700 and a gtx 1050ti with a 460 watt psu.

*I want to upgrade my gpu to a 1660 ti which has a recommended psu of 450 watts and i heard 460 is not enough and i should upgrade my psu to something better*

1) As i have never built a pc or done any upgrades in one, i have been researching and decided to open up my xps to get a feel for what some things look like. When trying to swing out the psu, with both hinge things unlocked, it was only able to swing out about 80% of the way. When trying to swing the chassis out enough so that it is parallel with the front panel, there is a lot of resistance and i feel like i might snap or break something. Is the chasis not supposed to swing out that far or is the resistance normal or is there an issue with my pc?

2) Can you provide me with a video or tutorial of someone upgrading the psu on a dell xps 8930 or a step by step manual?, as the cable management was confusing. 

Thanks!

@JimmehBart   Can you provide me with a video or tutorial of someone upgrading the psu on a dell xps 8930 or a step by step manual?, as the cable management was confusing. 

XPS 8930 Fan & PSU Upgrade