Question regarding my PSU and Radeon HD 7770 graphics card

[Hris112]

Hi, I have kind of an old PSU and I want to run a Radeon HD 7770 on it, just temporarily until I buy a new power supply. The model of my current PSU is ATX-500w Switching Power Supply. I really can't find any information about this one on the Internet. I checked the amperage and it is 17A on the 12v rail. Since it is a PSU from like 2007 it doesn't have 6 pin PCI-E connector, instead it has Molex 4pin. I was wondering if I'm safe using a HD 7770 with a 4pin to 6pin adapter which comes with the card. I'm only going to use this PSU for a month or two until I get a new one

oh btw I forgot to add im not going to be performing any overclocks on the video card or any other component of my system, atleast not until I get a new PSU

 

[jimthenagual]

The 7770 requires 19amps on the +12v rail. You have enough watts, but I don't think your PSU will be up for the task.

 

[fudoka711]

Yes, you should be safe using a molex 4pin to 6pin adapter.

The hd7770 draws less than 80W under load so you will be fine even with an older, cheaper psu - especially since its only temporary.

When you do go to buy another PSU, you will only need one that's 420-500W. Make sure its by a decent brand like Corsair or Antec though. If you do play on upgrading your GPU at any other point down the road, you may consider buying a beefier PSU.

 

[Hris112]

thanks to both of you for your answers
Some people adviced me to buy the 7750, but the point is I really don't want to downgrade to that to fit a PSU that I will only be using temporarily

 

[coozie7]

+1 fudoka711: The HD7770 power consumption only just exceeds the 75W available through the PCI-E slot itself so you'll be fine using a molex/PCI-E adaptor.
Other good PSU makers: Silverstone, Seasonic, OCZ, Pc Power and Cooling, Rosewill (capstone series), FSP and XFX, Minimum 400W with at least one 6-pin PCI-E connector, expect to pay less than $60 (US).

 

[Hris112]

thanks for your input guys, my HD 7770 arrives tomorrow. I'll install it, test it then post again and let you know if it's working okay

 

[Hris112]

Hi again. I'm happy to say that I received my HD 7770 and installed it today. At first, there was a little problem that took me about an hour to solve. I removed my old nVidia drivers through the control panel and then used Driver Sweeper in Safe Mode. Before I installed the new drivers, everything was OK, but the moment I installed them CPU usage was always at 50% at idle and 90-100% when browsing or doing some light work and the PC was really slow. I downloaded and used Process Explorer and there was this process Hardware interrupts and DPCs that was using my CPU so much. I looked for solutions in google and a guy said that uninstalling Microsoft UAA Bus Driver for High Definition Audio instantaneously fixed it for him and it completely fixed my issue the moment I did that. I have no idea how removing this UAA Bus Driver for HD audio fixes a problem after installing VIDEO drivers, but it does. If someone knows how, I'll be happy if you let me know.
Now I put my HD 7770 in a pretty old rig with a pentium 4 HT 3.0GHz and 1.25GB of RAM. I tried GTA IV and I was amazed that it ran. I set the settings to medium with shadows off but sometimes gameplay stutters, probably caused by my graphics card having to wait for the CPU to catch up with it. It's still very playable but I uninstalled it because I want to play it maxed out when I build my new system.
After that I ran MW3 with every setting set to high + 2x AA. I didn't check the FPS but it was super smooth, never fell below 35fps for sure. I wondered why the minimal requirements say I need at least a X3 core CPU when it performs so great on a P4 HT. I guess the game is very well optimized.
I can say that I'm very happy with my HD 7770. If it can perform so well with a P4 HT, it will be a monster with a PhenomII 965BE.