Radeon HD 6850 GPU Upgrade But Is My PSU With These Specs Enough?

GreenJorge

Honorable
Dec 25, 2012
14
0
10,510
Hi everyone, I'm upgrading to a Radeon HD 6850 to play new games etc. However, I want to avoid damaging my hardware if my PSU is too weak. I have a ATX 12V 400W PSU with these specs:

VOLTAGE


+3.3V +5V +12V1

18A 20A 8A


I understand that the card requires a minimum of 500W but I only ask this because I don't want to stretch my budget buying a better PSU and I really have no idea how to install them. I simply want to install the GPU and get on with it.

Thanks a lot in advance.


Here are my full specs:
ndows 7 Home Premium 64-bit
CPU
AMD Athlon II X2 250
Regor 45nm Technology
RAM
4.00 GB Single-Channel DDR3 @ 401MHz (6-6-6-15)
Motherboard
ASRock N68C-S UCC (CPUSocket)
Graphics
F22 (1920x1080@60Hz)
ATI Radeon HD 5400 Series (ATI AIB)
Hard Drives
466GB Seagate ST350041 3AS SCSI Disk Device (ATA)

Thanks a lot. :p


 

socialfox

Distinguished
If I read that right and the 12v rail is a single one, and it only has 8 amps that is absolutely a NO! The AMD website recommends a minimum of 500 watts but you could settle with a high quality 450 watts if you want.

Edit: You will want around 11 amps for the video card ALONE. That excludes the rest of the system that draws from the 12v rail. Also what make and model is this power supply?
 


Hi - you should be looking for 28 & up +12v amps, when you see

higher 3. & 5v amps than 12v, it suggests a very poor and/or
very old psu.

Tom
 

InvalidError

Titan
Moderator

That's AMD's PSU rating recommendation, not the GPU's actual power requirement.

A stock HD6870 would be closer to 180W peak power. Once you add the rest of your PC, you would get somewhere in the neighborhood of 300W total PSU load.

Since both the CPU and GPU get most of their power (about 240W or 20A in this case) from the 12V rail and yours is only rated for 8A, your PSU is a no-go.

As GreenJorge said, your PSU may be older than the shift towards 12V-centric power distribution (shouldn't be the case if it has an ATX12V cable), grossly imbalanced or simply poor design. As it is now, I am almost surprised your system ever worked.
 
+3.3V +5V +12V1

18A 20A 8A

Have a feeling you missed part of the Label -- If it were just a single +12V there is no reason they would have listed it as +12V1 (and as the others have said if 8A is the only +12V that would mean you only have about 100W available on the +12V rail which wouldn't be enough for some CPUs let alone an entire system !!) -- even if it is dual rail it is probably only a 250W or so PSU so you will most likely need a new PSU for any GPU upgrade - so just to be sure ggo back and find out what the rest of the +12V say (ie.is it only 2 rails +12V1 + +12V2 or does it have 3 or 4 rails ??) What brand PSU is it and what does it say it's total Wattage is ?
 

InvalidError

Titan
Moderator
Some manufacturers use the same generic label template across multiple PSU models and may list v2/v3/v4 as NA, "X", "0", blank, etc. when not present on a specific model.

If cheap PSU manufacturers are willing to shave 2-3 years of trouble-free operation beyond warranty to shave $0.50 off the BoM, they likely also welcome shaving $0.05/unit by not having to make, stock and manage model-specific labels... the assembly line needs in-line printing to fill out serial numbers anyhow so may as well use that to fill out model# and ratings as well.
 


True BUT even a cheap 180W (like this 1 )unit that has a single +12V rail has a rating of 10A on that rail !! so a PSU with a single rail of 8A makes no sense !!! ( a dual rail with 8A on each rail would be possible as would a single rail of 18A -- so unless the OP has a 100 - 150W PSU there is something wrong with the stats he posted !
 

InvalidError

Titan
Moderator

OP said he had a 400W PSU and the sum of what he listed as its ratings only comes out to just above 300W so you should be correct about something being missing.

Then again, this wouldn't be the first PSU with total outputs coming up short on the total label power or whatever that power may be implied to be by model numbers.
 



Nor the last I'm afraid!
 


Actually what he posted comes out to 255W ( Amps * Volts = Watts ) so quite a bit short of what a 400W unit would list which is why I 'm thinking there is something missing or he is guessing on the 400W part also - But either way the answer to his initial question doesn't change as it is not worth chancing hooking up a 6850 to that PSU !