• Competitor rules

    Please remember that any mention of competitors, hinting at competitors or offering to provide details of competitors will result in an account suspension. The full rules can be found under the 'Terms and Rules' link in the bottom right corner of your screen. Just don't mention competitors in any way, shape or form and you'll be OK.

GTX560Ti on a '400W' PSU?

nocturnal1974

nocturnal1974

nocturnal1974

Associate
Joined
20 Dec 2010
Posts
160
This may sound ridiculous but I have an OCZ StealthXStream 400 W (OCZ400SXS-UK)... apparently one of the best in its class and reviewed in detail here...

http://www.hardwaresecrets.com/article/OCZ-StealthXStream-400-W-Power-Supply-Review/794/1

Basically the PSU can output 453W and these are links to testing data below:

http://www.hardwaresecrets.com/article/OCZ-StealthXStream-400-W-Power-Supply-Review/794/8

This is the label on the PSU:

http://www.hardwaresecrets.com/fullimage.php?image=18664

Running 'eXtreme Power Supply Calculator Lite v2.5' my whole system is analysed as follows:

Minimum PSU Wattage: 297 W
Recommended
PSU Wattage: 347W

My system is an i3 530, 4GB, 1 HDD, 1 BDROM and I would love to get a 560Ti as I am a FSX fan. I had an Asus 6850 which became faulty, I got refunded and I haven't replaced the card since.

So I would like to hear from PSU experts as I know I'm going to hear 550W+ recommendations and after a lot of reading I know some PSU's with a much higher claimed rating aren't as good as the little OCZ.
S
 
betaspin said:
You have +12V1=17A and +12V2=14A which, taken together, is just 1A over the required amperage. Seems a bit too close.
Click to expand...

He's still got the cpu to power with that 12v, i see shutdowns and reboots in the future when the gpu is stressed, definetly need a better psu.
 
Label says 372W for both 12V rails... i.e. 12 x (17W + 14W)

560Ti uses 170W max ( not Furmark! ) leaving 202W for the 12V Rails, 81W for 5V & 3.3V Rails.

This system (at this time of typing) on full load would be lucky to use 120W and Mr. Core i3 530 uses 73W at full capacity

It would be fun to try it, I originally thought an underpowered PSU could fry a video card and a cheap one could, however I know this one has a protection circuit, the theory is it should simply shut down without any damage to PC or PSU...

One thing I learned whilst researching this area... the huge % of PC's sold with top spec gear... i5, i7, 6950, 560Ti etc. etc. A £1000 worth with a £15 power supply which on reflection I know fried a lot of PC's or cause all the problems with crashing and instability. Always see this on ebay!!!

Another is my PSU could be very different to one tested in the USA or anywhere... every PSU is probably not exactly the same just like a car albeit a much simpler device ... i.e. one can acquire a lemon or a semi-lemon :)
 
Last edited:
nocturnal1974 said:
Label says 372W for both 12V rails... i.e. 12 x (17W + 14W)

560Ti uses 170W max ( not Furmark! ) leaving 202W for the 12V Rails, 81W for 5V & 3.3V Rails.

This system (at this time of typing) on full load would be lucky to use 120W and Mr. Core i3 530 uses 73W at full capacity

It would be fun to try it, I originally thought an underpowered PSU could fry a video card and a cheap one could, however I know this one has a protection circuit, the theory is it should simply shut down without any damage to PC or PSU...

One thing I learned whilst researching this area... the huge % of PC's sold with top spec gear... i5, i7, 6950, 560Ti etc. etc. A £1000 worth with a £15 power supply which on reflection I know fried a lot of PC's or cause all the problems with crashing and instability. Always see this on ebay!!!

Another is my PSU could be very different to one tested in the USA or anywhere... every PSU is probably not exactly the same just like a car albeit a much simpler device ... i.e. one can acquire a lemon or a semi-lemon :)
Click to expand...

is it worth the risk?

btw it's AMPS on the 12v rail and not Watts! ;)
 
A 400W PSU will be fine with a 170w graphics card and an i3 system.

EVGA may be assuming lowest quality PSU when they state it needs a 500W PSU. A cheap 500W PSU may only have 20 Amps or less on the 12v rail.

At 170W the 560Ti will draw only 14 Amps at 12v, some from the PCI express power leads and some from the interface. No 560Ti will draw anywhere near 30 Amps from the 12v source.

Of course it'd be nice to have a 600W PSU to power this low power system but in reality it's just a waste of money.
 
If you look carefully at the two 12V rails on you PSU, +12V1=17A and +12V2=14A, it will be necessary to make a very good plan as to how to attach various devices to the rails. Most probably, the motherboard and CPU go on the 17A +12V1 rail. Then the question is whether you can put both of the 6pin 570 Ti connectors on the +12V2 rail (the card will be also able to take up to 75W from the motherboard). Still, it will be way too easy to overload one of the rails and have to deal with PSU shutdowns.
 
Let's put it this way.

My system including an i7 920 overclocked (130W ish) with a HD6950 (200W ish) only draws 406W from the wall with a 100% Prime95/100% Furmark load so you will be fine.

406W draw at the wall at 90% efficiency is only an actual 360W PSU usage by the way, so theoretically you could use my system with your 400W PSU.

People have been buying needlessly overpowered PSUs for years and unless you fancy going SLI with the 560ti then buying a 600W+ unit is needless.
 
Most probably a 400W PSU with a >30A single +12V rail would work fine. One close example I know of is the Nexus Value 430, a 430W PSU with a single 33A +12V rail. With two weaker +12V rails, it is way to easy to overload one of them.
 
Yes but each rail can do up to 26A (in tests) on their own as they are produced by a super barrier rectifier diode rated at 30A. You could put the entire system on one rail (if that were physically possible) and it would run fine, although I wouldn't recommend it.

In order to do that we increased current on the +12V2 rail until the power supply shut down. This happened when we tried to pull more than 26 A from it.
Click to expand...

Manufacturers always leave a margin between what is written on the label (14 A in this case) and the level the OCP circuit is really configured (26 A in this case). We always like to see this margin as tight as possible.
Click to expand...

FSP/OCZ have used rails like this in their supplies for years and continue to do so to enable end users to balance power draw without needing to think about it.



You will need a dual Molex to PCI express 6 pin lead to power the card of course.
 
Well, drawing 26A from a rail nominally rated at 14A for more than a couple of minutes is likely to cause an overloading or thermal shutdown in a well-designed psu free from manufacturing defects which, in most cases, is a unnecessary risk.

By the way, despite the fact that the published TDP of the 560 Ti is 170W, various reviews put its maximum power consumption under FurMark at 200-210W. The "safe" NVidia card to use even with a good 400W PSU is the 550 Ti.

Just had a look at an Antec EarthWatts EA-380D I replaced a while ago and it turned out that this 380W psu has two +12V rails rated at 17A and 15A but, of course, Antec are way more conservative than other manufacturers when reporting total power ratings.
 
Tealc said:
People have been buying needlessly overpowered PSUs for years and unless you fancy going SLI with the 560ti then buying a 600W+ unit is needless.
Click to expand...
True, if a company advises you a 500W PSU is needed they set the requirements high so the card will run on a 500W Generic crap PSU.

A high quality 400W PSU will be enough.
 
betaspin said:
Most probably a 400W PSU with a >30A single +12V rail would work fine. One close example I know of is the Nexus Value 430, a 430W PSU with a single 33A +12V rail. With two weaker +12V rails, it is way to easy to overload one of them.
Click to expand...

I would like to completely understand this rails business.

Is one of the rails for the extra juice CPU 4 pin plug?

The other is obviously for the card being PCI-E 6-pin connector?

If this is true which one is rated '17A' and which is rated '14A'?

I'll never be using Furmark EVER so 170W divided by 12V is 14.17A maximum current draw! Why on earth would you need 30A????

Also the card draws power from 3 sources: up to 75W directly from the motherboard leaving 95W distributed between the 2 6-pin PCI-E connectors.

Can any of you lend me a GTX560Ti so we can put this discussion to bed? :D

I'm enjoying the PSU education here and some of you are getting physics lessons

Power = Current x Voltage

Current = Power (divided by) Voltage

Current measured in Amps (A) Amperes and Power measured in Watts (W) 1Watt = 1 Joule per second
 
You will have to read the manual for your PSU (always the best place to start at imho) and look at the connection diagram. Most probably, the motherboard connector and the cpu plug are on the 17A rail, but it is up to you to check that. Crysis 2 with DX11 @ 1920x1080 and max settings is not much gentler than FurMark at times.

There is no need to invoke work here and btw, for electrical appliances work is most often measured in kWhs and not in Joules.
 
This has been going on for years. The simple fact is that so long as the PSU is of a good quality then you are fine.

I have a 500w PSU and people told me to buy a 750w one!! lol The one I have is doing just great with an i7 930@4ghz and a 6950 OC'd. That's with all the HDDs, H70 and a load of other stuff. Never had a single problem with it.
 
No, upgrade your PSU your gonna need more power for the GTX 560 Ti, i have one myself and i've tried it on a 400W power supply and had issues, + that PSU was Corsair, upgraded to a corsair 750W and its fine. :rolleyes:

GL
 
betaspin said:
You will have to read the manual for your PSU (always the best place to start at imho) and look at the connection diagram. Most probably, the motherboard connector and the cpu plug are on the 17A rail, but it is up to you to check that. Crysis 2 with DX11 @ 1920x1080 and max settings is not much gentler than FurMark at times.

There is no need to invoke work here and btw, for electrical appliances work is most often measured in kWhs and not in Joules.
Click to expand...

btw I was just describing what a watt was:D

I consulted the manual... the (+12V2)14A rail is exclusive to the 4-pin CPU connector...

Leaving the (+12V1)17A rail for everything else ( motherboard, video card, HHD, BDROM etc.)

so still polar opposite advice (all welcome off course)

richardinger what was the model of your Corsair 400W?

I played Crysis 2 on 1650 res max settings with a Radeon 6850 and I knew the machine was being put through its paces, my PSU fan was a lot louder than normal as was the 6850 fan BUT it never crashed (6850 uses 43Watts less than 560Ti at Max TDP). Completed C2 and got Crysis1, loaded it up at 1080p Max settings and the Radeon 6850 died R.I.P (suddenly 5 mins into the game my PC sounded like a Vacuum cleaner, this was the 6850 fan, I switched the PC off at the mains turned it back on and artefacts appeared in 3D which worsened to the Win7 Aero Desktop)
 
You must log in or register to reply here.
Back
Top Bottom