HD 5770 With 400 Watt Psu?

[secondgoat]

Hi there. I was planing to buy a new gpu without change any other parts so i considered Hd5770 best card that i can buy and suits my system. It has low power consumption and good performance also a next gen card etc..
My current specs:
Athlon X2 5000+ 2.6ghz
Foxconn k8m890m2ma (a crappy enrty-lvl board with pci ex 1.0)
Radeon x1650pro
2 sata hdds
1 pci satellite tv tuner

and a crappy generic 400watt psu with 12V 18amp.

I have calculated total watt on eXtreme Power Supply Calculator it says 320 watt required which is just 20 watt more than my current x1650pro. But i couldnt trust it because i saw someones on forums having problems even 450-550watt psus so now i doubted if my psu can handle hd5770. So question is can i use this card withput any problem with this psu? Whats yours opinions?

Thank you.

 

[JofaMang]

Your PSu should be ok to run the card on your system. The power consumption difference is very small, as the 4770 is a very efficient card. I had an almost identical computer to yours until I built this one, (4800+ x2, 1650 pro 512, 400watt generic PSU) and I wouldn't have been afraid to put a 4770 in it.

BUT if the PSU is very old, it probably isn't even able to match it's original specifications. You might run into power shortages. A 4670 is a great lower power alternative which is cheaper, but if you are set on a 4770, be prepared to replace your PSU should it not be up to snuff. Another risk is that if the PSU isn't strong enough, it may blow and take vital system components with it, if it is cheap enough with no overpower protection.

 

[rolli59]

I recommend a new PSU there are some good deals out there for $40-50
Those 20 extra watts are going to be on the +12 volt rail which means you are loading it with extra ~2amps and it only rated at 18. It will be pushing it but the only way to find out is try.

 

[jsc]

Jofa, OP said 5770.

second goat, your problem isn't just the overall power rating of your PSU. It's the weak 12 volt rail.

I figure 8 amps for the CPU and 8 amps for the new video card. Figure 2 amps for 2 HD's and an optical. And I will bet you that your PSU cannot deliver 18 amps once it warms up to operating tetmperature.

One of these would work nicely:
Corsair 400CX (30 amp 12 volt rail)
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139008

 

[shubham1401]

You should change your PSU.
18A on 12V rail means less than 70% efficiency which also means low quality components are used.

That 400CX is an excellent PSU.Go for it.

 

[jonpaul37]

+ 1 for upgrading the PSU, a good quality PSU will last you a long time and give room to upgrade, start there, ALL other upgrades will come easier.

If you really want to future-proof, get a 600w+ PSU with at least 2 x 6-pin PCI-E connectors (4 would be better though) This way, you'll be able to use this power supply for the next few years and not have to worry about upgrades.

Good brands to go with are the following:

Corsair
OCZ
PC Power & Cooling

 

[secondgoat]

Ok ok a new psu is a must for HD5770. I dont want to make any upgrade right now, i will make a compeletly new pc in future, for now i just want to play some newest games with 1440x900 medium-high settings with current system.

One more question: what about hd 5750? I know overall watt doesnt mean anything but psu calculator gives me same watt as x1650pro when i select 5750. It has lowest power requirement in this cards so if x1650 works without problem 5750 should work too isnt it?

 

[rolli59]

It has a better change to work since it requires less power. Both a new PSU and GPU can be carried over to a new build!