# Typical power consumption for a DVD rewriter?



## Phobia9651 (May 9, 2013)

Hi everyone,

I wanted to redo my cabling and I had the idea of connecting several devices to a Molex-to-4x-SATA cable (the Bitfenix Alchemy one). But since Molex only supplies up to 35W I was wondering whether this would work.
The 4 devices I wanted to connect:
2x 2TB Caviar Greens = 2x 5.3W peak | 2x 1.75 A
1x Crucial m4 64GB = 2.6W peak (according to Tom's Hardware measurements)
1x LG GH24NS90 = 2.0 A / 2.5 A (according to the sticker on the device)
I read somewhere that the typical peak power consumption of a DVD rewriter is around 20W. Does anyone know a more specific value? Since the margin to 35W is rather small in total. Or shouldn't I be worried?


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## RCoon (May 9, 2013)

urza26 said:


> Hi everyone,
> 
> I wanted to redo my cabling and I had the idea of connecting several devices to a Molex-to-4x-SATA cable (the Bitfenix Alchemy one). But since Molex only supplies up to 35W I was wondering whether this would work.
> The 4 devices I wanted to connect:
> ...



1.21 gigawatts.

I kid, 20watts MAX when burning data permanently. Usually around 16-18


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## AsRock (May 9, 2013)

RCoon said:


> 1.21 gigawatts.
> 
> I kid, 20watts MAX when burning data permanently. Usually around 16-18



But wouldn't 2.5A be around 30w although this would be the device's max usage and i bet it's rare it hits that kind of usage.


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## RCoon (May 9, 2013)

AsRock said:


> But wouldn't 2.5A be around 30w although this would be the device's max usage and i bet it's rare it hits that kind of usage.



If it actually pulled at 2.5A then maybe it would hit 30w. But i sincerely doubt it would. DVD drives are surprisingly efficient.


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## Geofrancis (May 9, 2013)

i have never been a fan of molex connectors they burn up too easily. a sata> 4x sata adapter would probably be a better idea


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## Phobia9651 (May 9, 2013)

Thanks for the advice guys, so I would be better of not hooking them up to the same molex. Sadly that means more cables =(



Geofrancis said:


> i have never been a fan of molex connectors they burn up too easily. a sata> 4x sata adapter would probably be a better idea



Do you got a link for me to such an adapter/splitter cable? I know Bitfenix has none of those.


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## ne6togadno (May 9, 2013)

12v*2.5a=30w


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## Geofrancis (May 9, 2013)

i had a couple of these in my server





http://www.ebay.co.uk/itm/Startech-...uting_CablesConnectors_RL&hash=item232a03fa60


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## FR@NK (May 10, 2013)

All four devices will work fine on that one power connection. Molex isnt rated as low as 35watts.



Geofrancis said:


> i had a couple of these in my server
> http://i.ebayimg.com/t/Star-Tech-4x...9b/$T2eC16FHJFwFFZ3uQ(3hBR,t9bQkIw~~60_35.JPG
> http://www.ebay.co.uk/itm/Startech-...uting_CablesConnectors_RL&hash=item232a03fa60



That wont provide enough power. A single SATA connector is rated for 4.5a per 12v, 5v, and 3.3v line. The 4 devices need 1.75a + 1.75a + 2.5a ≈ 6 amps on the 12v line.


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## Geofrancis (May 10, 2013)

FR@NK said:


> That wont provide enough power. A single SATA connector is rated for 4.5a per 12v, 5v, and 3.3v line. The 4 devices need 1.75a + 1.75a + 2.5a ≈ 6 amps on the 12v line.



2x 2TB Caviar Greens = 2x 5.3W peak                5.3/12=0.88A
1x Crucial m4 64GB = 2.6W peak                       (runs on 5v)
1x LG GH24NS90 = 12V 2.0 A / 5V 2.5 A            

so really the power consumption on the 12v is only 2.88A max with what he is wanting to run.

i just prefer the sata connectors reliability the pins on molex connectors get damaged really easily so it makes a bad connection causing all sorts of problems.


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## FR@NK (May 10, 2013)

Geofrancis said:


> 2x 2TB Caviar Greens = 2x 5.3W peak                5.3/12=0.88A
> 1x Crucial m4 64GB = 2.6W peak                       (runs on 5v)
> 1x LG GH24NS90 = 12V 2.0 A / 5V 2.5 A



The Greens pull 1.75a @ 12v each
5.3w is the heat dissipation rating(the amount of heat it puts out)

and the burner pulls 2.5a @ 12v from the sticker:





Thats about 6 amps total which I think is too much for a single SATA power connector since they are rated for 4.5 amps. Do you agree Geofrancis?


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## OneMoar (May 10, 2013)

the ammount of load you can place on a given chain is determined by the gauge of wire and the power supply its self if it uses 
18 Gauge wire then you can safely draw 10 AMPs of power of over it 
if its 22 then you can safely draw 7AMPs
if its 24G wire you can safely draw 3.5amps ect ect ect 
most PSU's use 18or 22 Gauge wire for the 12V and 24 for the +5V
barring any limitations with the psu its self it should be fine
*connectors* don't have limitations other then the limits or the wire that feeds into it when it comes to Molex. a molex plug is just some wires terminated with a MALE bullet connector in a plastic shell
Sata connectors are a bit different because of the difference in Wire Gauge Vrs the Connector-pins generally I would say that a Single sata "connector" could handle 7 amps without much fuss


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## FR@NK (May 10, 2013)

OneMoar said:


> difference in Wire Gauge Vrs the Connector-pins generally I would say that a Single sata "connector" could handle 7 amps without much fuss



You're right. I forgot here at techpowerup we push our hardware to its limits! 7 amps over the connection rated for 4.5a would be fine as long as you place a small fan over the connector


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## OneMoar (May 10, 2013)

FR@NK said:


> You're right. I forgot here at techpowerup we push our hardware to its limits! 7 amps over the connection rated for 4.5a would be fine as long as you place a small fan over the connector
> 
> http://www.aerocooler.com/images/AF0064-a.jpg



the connector is Specified for 4.5  there should be no problem with drawing 7 Amps though it but that point is m00t as you will never find a device that can draw more then 5Amps though a single connector


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## Phobia9651 (May 16, 2013)

Haha, well I'm not fully convinced what is best now... 
The goal is simply to use as little cables as possible powering those 4 devices.
I ordered the StarTech cable already, eventhough I thus might be wiring it up differently.
I found this interesting (though dated) link the other day: http://www.playtool.com/pages/psuconnectors/connectors.html#sata
I got an AX850 psu, but frankly the provided sata power cable is not long enough and for some reason the connectors are upside down (perhaps Corsair/Seasonic still thinks people mount their psu's at the top of the case).
My initial idea was to hook those 4 devices to the Bitfenix cable which I then connect to a Molex cable coming from my psu, since I got a molex power cable in use anyway (to power my Xonar DX and 3 large 230x200mm casefans). 
I guess the easy solution now would be power the DVD rewriter with Corsair's sata power cable (which has 4 connectors) and hook the 3 SSD/HDD's to the StarTech extension/splitter cable. Which I then connect to one of the remaining free connectors of the Corsair cable.
Or does anyone have a better idea?

PS. Thanks for all the help/advice!

EDIT: I ordered a Plextor M5 Pro 512GB to replace my Crucial m4 64GB. It was on sale for € 348 and I finally got enough space to actually put all my programs and games on the SSD. 
But to recap the device's power needs:
DVD Rewriter: 
5 volt = 2.0 A
12 volt = 2.5 A
WD Caviar Green (per device):
5 volt = 0.7 A
12 volt = 0.55 A
Plextor M5 Pro:
unknown, but for the 256GB variant 5 volt = 1.5 A


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## Geofrancis (May 16, 2013)

power consumption shouldn't be an issue. the main reason to hate molex connectors is they have a habit of making an intermittent connection that will disconnect if you even breath near it. sata connectors are made with much tighter tolerances so it will only disconnect if you pull the cables apart.


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## Phobia9651 (May 16, 2013)

Geofrancis said:


> power consumption shouldn't be an issue. the main reason to hate molex connectors is they have a habit of making an intermittent connection that will disconnect if you even breath near it. sata connectors are made with much tighter tolerances so it will only disconnect if you pull the cables apart.



So I shouldn't have worried to begin with?
Eventhough Frank's calculation was incorrect concerning the 12 volt power needs, based on my last post I'm above 4.5 Amps on the 5 volt wire though...


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## Geofrancis (May 16, 2013)

urza26 said:


> So I shouldn't have worried to begin with?
> Eventhough Frank's calculation was incorrect concerning the 12 volt power needs, based on my last post I'm above 4.5 Amps on the 5 volt wire though...



the connectors wont melt will you push 10+ A though them it should be fine.


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## Phobia9651 (May 18, 2013)

I got the SSD and splitter cable today, the Plextor M5Pro 512GB actually pulls 2.0 A on the 5V.
What bothers me though, why are those connectors of the spillter cable also inversed, eventhough people haven't been using top mounted psu's for a while now? Is there an easy solution to overcome that problem without twisting the wires too much?


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