Need more power for this 3850?

TimTim Southwest PA Icrontian
edited January 2009 in Hardware
I got myself a brand new Sapphire / Radeon HD 3850 from Newegg to upgrade from my old X850 Pro in my NF-7 computer. AGP slot.

Specs on system:

Abit NF-7 version 2.0, Barton core 2500+ CPU
Antec 400 watt PS 6 months or so old
2.5 GB RAM PC3200 DDR
XP Home SP3
2 Seagate hard drives, 7200.7 80 GB and 7200.9 250 GB. 1 CD-ROM / DVD drive, and 1 FireWire card. I'm using on board sound.
20" Samsung 204B LCD monitor. Runs on 1600 X 1200 for WoW and TF2.

I did a full reformat / reload of XP on my boot drive for maintenance / fresh install, and installed the 3850 with the supplied driver CD.

Ran it through tests on 3DMark 05 and 06, it did quite a bit better than the X850 Pro.

Went to play WoW. FAIL. FPS was skipping from 2 to 40 to 2 to 50, 5 seconds of freezing followed by 2 seconds of erratic movement, over & over.

Upgraded to the 8.12 hotfix drivers from Sapphire. No improvement. Tried a couple other drivers, no improvement.

So I start reading the box. Ah, this thing needs 30 amps of power, it suggests a 450 watt or greater PSU. I looked at the label on my PSU, one 12v rail puts out 15 amps and the other is 14.

I had been running the card off one rail only with its supplied Y adapter. At its default 669/829 speeds.

So I got creative. Rerouted the wires so each rail fed power to one hard drive and 1/2 of the Y cable for the 3850.

More FAIL. Now I can only get a flickering black screen. I can go to WoW or the internet, but the screen will flicker to solid black, and briefly flicker back to what I'm trying to see when it feels like it.

So I'm guessing I need a better PSU. I looked at Antecs and OCZs and Thermaltakes on Newegg, they list 18 or 19 or 22 amps per 12v rail, so I'm guessing the thing to do is feed the Y connector from TWO rails to exceed the needed 30 amp supply?

Since I'd want to keep this new PSU for my eventual upgrade, I'm looking at units in the 600-700 watt range.

For now, I reinstalled the X850 Pro, and with the 7.3 drivers it's running better now. But the 3850 will Chuck Norris the 850, no problem.

Comments

  • ThraxThrax 🐌 Austin, TX Icrontian
    edited December 2008
    The amp requirement on a video card is the combined total amperage of the unit. Any quality supply in the 600w range will suffice; just don't buy Antec. Stick to OCZ, Thermaltake, Corsair, etc.
  • TimTim Southwest PA Icrontian
    edited December 2008
    I have no problem buying an OCZ, Thermaltake, or Corsair PSU. But DON'T buy Antec? I thought they were one of the better manufacturers. Maybe that's changed in the last couple years?

    Anyhow, does my problem sound like it's power related, or could it possibly be a driver issue? I did all I could to see that it got clean factory drivers installed, and there weren't any other video card drivers on the computer either.
  • TimTim Southwest PA Icrontian
    edited December 2008
    I found an OCZ GameXStream 700 watt unit and read the reviews on it, it looks to be a pretty good power supply unit.

    Hope that helps the problem!
  • GnomeWizarddGnomeWizardd Member 4 Life Akron, PA Icrontian
    edited December 2008
    OCZ Silent stream 600 I own powers my rig below in my sig just fine
  • Mt_GoatMt_Goat Head Cheezy Knob Pflugerville (north of Austin) Icrontian
    edited December 2008
    Tim wrote:
    I found an OCZ GameXStream 700 watt unit and read the reviews on it, it looks to be a pretty good power supply unit.

    Hope that helps the problem!

    That is a decent unit and should work well.

    I have been preferring the single 12v rail PSU's and recently got the CORSAIR 650TX which the egg curently has for $99.99 and it is just great. I think it will carry me for a long time to come as it currently powers a quad core and a HD4830 with lots to spare!

    I quit buying Antec several years ago as they just weren't the solid PSU's they used to be.
  • WingaWinga Mr South Africa Icrontian
    edited December 2008
    Mt_Goat wrote:
    I quit buying Antec several years ago as they just weren't the solid PSU's they used to be.

    Interesting. I'm using an Antec Truepower2 450W PSU in my rig, running a highly OC'd 4850, E6550 @ 3.1Ghz, 3 SATA HDD's, 2 SATA optical drives, Audigy sound card and about 5 case fans. Stable as hell and never given me a days problem. When did they start falling over with bad PSU's?
  • ThraxThrax 🐌 Austin, TX Icrontian
    edited December 2008
    Late 2007, early 2008.
  • QCHQCH Ancient Guru Chicago Area - USA Icrontian
    edited December 2008
    I remember buying a Earthware (or something) from Antec and it lasted less than a year. I probably should have sent it back but....
  • TimTim Southwest PA Icrontian
    edited January 2009
    I got the OCZ GameXStream 700 watt PSU today, put it in, and after testing it on the old X850 video card to see if the PC would work, I put in the 3850.

    Same problems.

    I called ATI tech support and Sapphire tech support. Tried a few different drivers, uninstalling between attempts.

    Big problem was that the screen will flash to blackness for 0.1-5 seconds at a time, whatever it wants to do. I'll only get random glimpses of whatever screen image I'm trying to see.

    The ATI tech guy, after learning that I'm using an NF-7 motherboard said something to the effect of the NF-7's nForce 2 chipset is old enough that even with updated drivers it can't really handle the 3850.

    Sound right to anyone? I wasn't sure about that idea.:confused2

    I think today was the last straw, I may just say F it and throw together a DDR2 / 775 / P35 chipset PC and drop in a 4870. My NF-7 has run great for years, but it's time for something newer that can handle modern hardware / software.
  • edited January 2009
    I am having a similar problem, I purchased this same card hoping it would give me a bit more life until I invest in a computer to take to college. I originally missed the note on newegg about it requiring 30A on the 12v, and purchased it. I quickly realized that problem when I purchased and upgraded to a Thermaltake 430W ATX12V. My problem is persisting still, despite assurances from a more computer savvy friend that the Thermaltake should be able to handle it. I've tried a BIOS update, driver updates from ATI and Sapphire. I've also unplugged all unnecesary peripherals, and none of it seems to help. Any fresh suggestions?
  • KometeKomete Member
    edited January 2009
    Tim wrote:

    I think today was the last straw, I may just say F it and throw together a DDR2 / 775 / P35 chipset PC and drop in a 4870.

    I think you have a winner there. You did give it a great run. I'm sortta in the same boat as you. I have an asrock 939 with a oc'd x2 cpu. It still works but it is way past time to upgrade.

    I think the fact that I spent soo much on the memory has stopped me from upgrading. But now with memory so cheap there isn't a reason not to upgrade.

    That e5200 chip delivers one heck of a bang for the buck if you OC.
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