Upgrading GPU, time for a new PSU?

I'm upgrading to a HD5870 now that my 4870 1GB can't hold up 120fps with my new 1920x1080 120hz Acer. It was fine on my old 1650 monitor which I ran @ 1440x900 usually.

Anyways, currently I have a 550w OCZ PSU. I'm worried that it will be pushing the limits when I upgrade cards with my current system. (e8400@4.0, 4 gigs ram, 2 HDs, Sound Card, Wireless card, DVD Drive, etc.).

I'm thinking of just grabbing an 800w or so so I don't have to worry about upgrading my PSU for a long time. This 550w has lasted me 4 years.

First do you think I need to upgrade, and second what's a good price on a PSU for 800w? It's been a while. I was thinking Corsair since I know it's quality, but I haven't really done price checking yet. What brands should I check against?

Thanks in advance.
10 answers Last reply Best Answer
More about upgrading time
  1. Nominal System Power for 5870 approx 362 +/- 25 Watts

    After installing GPU. Run HWMonitor and note +12V and +5 V voltage then run Furmark and note decrease in +12/+5 Votage. If Min level is above 11.6 for +12V and above +4.75 V for +5 V - good to go. (PS leave running for min of 15 to 30 Min to allow system to stablize in temperature.
  2. Corsair, Antec (Earthwatts and Truepower series), Seasonic, are some reliable brands...

    You wanna get a modular PSU or a non modular? Also, think about the budget?

    Which OCZ power supply is it?
  3. depending on what else you have i'd suggest you are fine,my Q9550 with gtx470 runs at 330W max, even if this was all 12V then thats <30A i'd suggest my 470 uses more power than your proposed 5870?
  4. I can't remember the exact name, I'm at work but I'll have to check when I get home. I know it has Stream in the name. Like StealthXStream or something?

    Actually after looking on newegg, I'm afraid it might even be 500w only. If it is, I'd probably definitely want to upgrade. I put in all my system specs in the Asus Power Calculator and it came out to 550w with the 5870.

    Also I'm not sure about modular vs non-modular. Is there a better version?

    Budget around $100 or so. I was checking out some of Newegg and this 750w Corsair is $109 ($99 after rebate).

    Is that the best for around that price level you would say?
  5. Nvm about modular vs non-modular. I researched it. It seems like this Antec semi-modular seems good.

    Same price as the Corsair with less cables. Most of the included cables are stuff you need, while all the extras are modular.

    Seems good?
  6. For $70 this would be a good choice

    That 550 watt from calculator is IF YOU grab one of the "Lessor" quality PSUs

    The corsair 650 Watt will handle your system easily.

    Modular/ not Modular, this is 2ndary to choosing a GOOD PSU. There are Pros and cons. Pro - Better cable management = slightly improved case airflow. Con - adds another set of connector pins = added SLIGHT voltage loss, adds a Point of increased problem area 3/4 yrs down stream.

    Added: If you plan on adding a 2nd 5870 in xfire then go with the corsair 750, otherwise the corsair 750 is overkill.
  7. Well I was mainly grabbing the 750w so I don't have to upgrade again for a while. I'm assuming I will be upgrading to an i7 build 1-2 years from now. I'd rather just pay an extra $30 for a 750w now instead of maybe having to upgrade in the future.

    Is the voltage loss that big of a deal? I would rather have minimal cables then a bunch of cables I don't need.
  8. Best answer
    Then go for the 750. My crystal ball gets somewhat clouded at times, But not only will "Newer GPUs be faster, HOPEFULLY they will be less power hungry.

    My goal in choicing the wattage is (1) Pick the BEST quality I can while looking at (2) less than 80% under "Expected/planned" full load and greater 20% at idle - Can not alway satisfy both.

    On voltage loss - no. probably less than 0.1 V. As to 3/4 years later, That is a unknown. All connector pins will develop some oxidation on the male/female pins which increases the "Loss". Normally just cycling the connor a few times removes this oxidation. Gold plated pins are less subject to this oxidation.

    Do not let this be a big concern ( I use both) Below is just an explanation.
    Connectors have greater I squared R loss than the wires (Power loss in watts).
    For example: If a connector pin Has 0.005 Ohms (New) and you have only 5 Amps of Current this would equate to .005 ohms x 5 volts x 2 (Have one set in + side and one set in return side) = 0.025 Volts as Oxidation could easily increase this to .05 ohms for a loss of .25 Volts (after several years. NOTE with Modular supplies you have 2 sets in series, One at PSU and One at Motherboard , or one at GPU.
  9. Thanks for the info.

    At least with this Antec semi-modular the main connectors people use are not modular, it just let's you leave out all the extra cords that alot of people might not need.

    Probably gonna go with that one then. Thanks again.
  10. Best answer selected by Strife025.
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