How Many Drives Can a Cable Handle?

[DerrickChen]

Hello, everyone

I wonder how many SATA power connectors I can attach to one cable from my PSU.
My PSU is DELTA 550W Platinum. (I don't think this brand is available in some places? Afaik, they do OEM mostly.) It's dual rail 12V and uses 18 AWG wires, here's a photo of the specification.

Don't panic, that's Simplify & Traditional Chinese.

I heard usually you can attach 4 connectors. Anyway, I have 4 HDDs and a Blue-Ray drive. An HDD draws 2~2.5A while powering up, but I don't know how much a DVD drive draws. I saw a post on Anandtech asking pretty much the same question, here's the link.
https://goo.gl/7VSXAE


Down below are not related to the main topic, warning ahead. But if you want to take some time to answer these tedious questions, thank you!
Also, what are the 3.3V cables for HDDs, is it for latency to spin up or...?
It seems that not many people sleeve their SATA power cables? And I suppose there's no way I can use the sleeveless method, but I guess a right adhesive would do the job.
I'm also curious about one thing if I insert my GPU in the first slot, it will block my SSD with a cool looking heatsink. Wouldn't it suck to just block the view? But insert it in the second slot is close to the PSU shroud which I assume make the airflow bad?

And why make the distance between each SATA power so long? For those who don't manage their cables? Are you willing to bend your cables that much to fit it into the case? Btw, it's MasterBox 5.

If you read all the way down here, Kudos! Thank you for taking your time for these again!

Cheers,
Derrick

Edit, pictures links... They were not showing. But now you can see them! Word choice, no one likes to be too repetitive!

 

[madmatt30]

You already answered most of your own questions in all honesty.

Optical drive 12-15w on full spin cycle - singly from the 12v line on the sata cable.
Traditional Platter drive - 4-9w depending on use - spindle motor is run from 12v ,circuitry is run from 5v
SSD - 3-6w from 5v only.

3.3v on the sata ?? NOt used for any peripheral I can think of at all,it was introduced on sata I suppose for future proofing & to give access to every voltage rail a PC PSU outputs.

GPU ? should be in top slot really which is full speed pci express 3 x16
The bottom slot is limited to 4 x speeds - Upto anything midrange gpu wise (gtx 1060/rx 580) it doesn't make a difference ,past that you may see a 1-2% performance drop off due to available pci express bandwidth.

The distance betewen sata power cables ??
Thats purely down to delta I think,you know yourself ,theyr'e majorly an oem manufacturer so their psu's are designed to be multi purpose - most traditional workstation/prebuilt pc's have a couple of optical bays with the hdd bay underneath & that distance between connectors means you can run an optical in the top slot & a hdd in the hdd bay from 2 plugs on a single cable.

Same reason the cable's arent fully sleeved to the ends of the connectors,delta dont care about aesthetics,its about funcionality & internal quality while keeping the costs down.

Id have no issue running twin sata splitters off any of those cables if necessary,you are not going to saturate the capacity of 18awg cabling or the connectors themselves with standatd sata peripherals.

 

[DerrickChen]

Ah, I get it! So it's for each 5v or 12v cables then! A 5V cable can tolerate up to 20A vice versa, and I just need to calculate how much for 5V and 12V then. Now I get it...

Thanks for your help! That's really helpful!

Haha, I forgot the x16 and 4x speeds on PCIE... Then it's time to say goodbye to the cool heatsink on Plextor...

As for the power connectors, I'll just detach all of them and readjust them for easier cable management. Time to sleeve all the cables with paracord!
And thanks again for your help! It's always nice to figure something out!