NVIDIA GTX 770 PSU requirements

[somechap99]

I'm getting to the point of wanting to buy and NVIDIA GTX 770 because I keep getting crashes with my Radeon HD 7770 when playing battlefield 4 (pulling my hair out - tried everything !!) plus obviously the 770 should give me better frame rates.

So I have a 550W PSU (I know a 600W PSU is recommended), this PSU has by the looks of it 2 x 12V rails, 1 at 19 Amps another at 20 Amps. I'm thinking the 20Amp rail would be sufficient to run a 770 but I'm not sure as I can't find any exact current draw specs of the GTX 770.


Can anyone help ?

 

[allocco91]

Maximum power consumption for the GTX 770 is about 250 watts.

http://www.tomshardware.com/reviews/geforce-gtx-770-gk104-review,3519-25.html

What brand is the PSU?

 

[VincentP]

A good quality 550W power supply is plenty for your system.

GTX 770 draws 230W.
This is spread over the PCI-E slot (up to 75W) a 6-pin PCI-E power connector (up to 75W) and an 8-pin PCI-E power connector (up to 150W).
If your power supply provides these two connectors, the load should be balanced between the two rails.
If the power supply does not have two PCI-E connectors, it is probably not suitable.

There should on your supply also be a maximum rating across the two 12V rails.
This is often labelled in watts rather than amps.
You want a rating of at least 450W on these 12V rails combined, on a good 550W supply this will be over 500W.

 

[zink1701]

Agreed but its recommended a 600W PSU with 42A on the rails to run that card with a basic setup (non SLI). Its probably overkill but that is the recommended minimum.

 

[somechap99]

Thanks for the replies that helps, I don't know the brand of PSU at the moment as I'm away from home but it wasn't a cheap PSU, I'll check for the dual PCIe connectors. I guess it wouldn't be wise to use a disk power to PCIe adapter or if I did I would have to be careful which 12V rails I used. I wonder what would happen if I connected separate 12V rails together or in other words are the inputs to a typical GTX 770 separate supplies or would they be connected together on the GTX 770 PCB ?

 

[VincentP]

Thanks for the replies that helps, I don't know the brand of PSU at the moment as I'm away from home but it wasn't a cheap PSU, I'll check for the dual PCIe connectors. I guess it wouldn't be wise to use a disk power to PCIe adapter or if I did I would have to be careful which 12V rails I used. I wonder what would happen if I connected separate 12V rails together or in other words are the inputs to a typical GTX 770 separate supplies or would they be connected together on the GTX 770 PCB ?

It is a good question about the various 12V supplies being linked together on the card, and one I doubt anyone here can answer.
Each PCI-E connector has a number of +12V pins and if you use molex to PCI-E adapters these could come from different rails.
These adapters are generally not a good idea. If the power supply was designed to power high end graphics cards like this, it will generally have the required PCI-E connectors (two 6+2 pin PCI-E connectors on a 550W power supply).

Using multiple 12V rails was a popular design in older power supplies, but this has largely been dropped in the best supplies available today in favour of a single 12V rail. The single rail design is more flexible and the multiple rails didn't really add any benefit.

 

[w4vz]

Hello,

Very interesting thread here. I think I found the cause of my problem but wanted to ask for confirmation.
I am running an EGPU with EVGA GTX770 2gb. Under load (even netflix) I get Freeze restart. I am suspecting to have bought the wrong PSU...

Can you please check for me: it is a 550W Modular Powercool Black PSU 80 Plus 12cm Fan SATA Power Supply PC-550AUBA-M bought on Scan website.
It says 36A on the 12v rail if I understand well :S ? I read that 42 A is recommended. Watts should be fine though ?
The description says SLI ready, can it be underpowered? did they lie ?

Im really desperate find the cause of my problem, right now my system is unusable... Thank you in advance

 

[somechap99]

Hello,

Very interesting thread here. I think I found the cause of my problem but wanted to ask for confirmation.
I am running an EGPU with EVGA GTX770 2gb. Under load (even netflix) I get Freeze restart. I am suspecting to have bought the wrong PSU...

Can you please check for me: it is a 550W Modular Powercool Black PSU 80 Plus 12cm Fan SATA Power Supply PC-550AUBA-M bought on Scan website.
It says 36A on the 12v rail if I understand well :S ? I read that 42 A is recommended. Watts should be fine though ?
The description says SLI ready, can it be underpowered? did they lie ?

Im really desperate find the cause of my problem, right now my system is unusable... Thank you in advance

For me I replaced every component in my PC (PSU, CPU, Motherboard, Graphics card) apart from RAM and guess what the cause of my crashes were - cheap / poor RAM (value RAM). The reason BF4 crashed and no other application wasn't load on the PSU it was because BF4 runs in 64 bit and my PC started using the top 4GB RAM, the 4GB serviced by the poor RAM. I replaced my RAM and ever since my PC has been rock solid. I suspected my PSU simply because I only got a crash after playing BF4 for about 30 mins or so i.e. after putting a heavy load on my PC but after upgrading to a 750W seasonic (I think) and still getting the crashes it was clear I couldn't be a PSU problem.
Having said that your problems could be due to your PSU but I would suspect you may only see problems when under load (if it's a lack of wattage / amps from your PSU), or perhaps your PSU is simply faulty / poorly regulated. The only way I found out was replacing all my components but I wanted to upgrade anyhow so it wasn't wasted money. I'd watch out for cooling as well as in whether it isn't heat related i.e. making sure your CPU heatsink is correctly fitted and up to the job.