Some Haswell info


  1. Posts : 24,479
    Windows 7 Ultimate X64 SP1
       #1

    Some Haswell info


    I sent an inquiry to Jeffery of ASUS support about some comments he made in Newegg's review section. I expressed concern about why so many ASUS Z87 boards were being returned as DOA. Here is his interesting explanation.
    Please add your thoughts or knowledge.

    Hello Gary,

    Looks like when the new Haswell board released their are some PSU that are not compatible with the board that won't allow the board to turn on. Haswell has a low voltage to turn on and these PSU are assuming the board isn't getting enough power which customers assume its DOA.

    When you purchase the Z87 board, you have the best contact to get things done in a timely manner and worry free as much as possible.

    Regards,
    Jeffrey
      My Computer


  2. Posts : 25,847
    Windows 10 Pro. 64/ version 1709 Windows 7 Pro/64
       #2

    I have no idea what that means.
    Gary can you put that in Ohio English?
      My Computer


  3. Posts : 72,041
    64-bit Windows 11 Pro for Workstations
       #3

    That sounds correct. Intel's Haswell processors feature a new sleep state that isn't compatible with all power supplies (PSU).

    Here's an interesting article about this.

    The big Haswell PSU compatibility list - The Tech Report - Page 1
      My Computer


  4. Posts : 24,479
    Windows 7 Ultimate X64 SP1
    Thread Starter
       #4

    Layback Bear said:
    I have no idea what that means.
    Gary can you put that in Ohio English?
    I'm writing from memory, but I think it means this: Even when a PC if "off" the PSU still is supplying a stand by voltage if it is plugged into the wall. When you hit the PC power switch the PSU responds with a quick voltage check of the board, maybe 200-300ms in lenth. IF the PSU detects a lower voltage than expected it won't "turn on" and there is no start up.
    As example only, say an older board draws 5V at start up and the Haswell board only draw, say, 0.8V the PSU will take that as a failure to start. Those figures are just guesses for illustration.

    I'm not sure if failing to wake from sleep is the same as failure to post, but sure seems related to Haswell's lower power needs.
      My Computer


  5. Posts : 2,973
    Windows 7 Professional 64bit SP1
       #5

    This was a known issue before Z87 boards and Haswell CPU's were even launched. There was a list of known good PSU's out as well. There will probably be a fix for this soon if it is a big problem. Intel isn't too big to make mistakes, but they usually clear them up in short order. Thanks for sharing this Gary.
      My Computer


  6. Posts : 25,847
    Windows 10 Pro. 64/ version 1709 Windows 7 Pro/64
       #6

    Thank you all. Now I understand,
      My Computer


  7. Posts : 24,479
    Windows 7 Ultimate X64 SP1
    Thread Starter
       #7

    You're welcome Jack. Don't feel bad, I don't understand half of what I know, hence my avatar.
      My Computer


 

  Related Discussions
Our Sites
Site Links
About Us
Windows 7 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 7" and related materials are trademarks of Microsoft Corp.

© Designer Media Ltd
All times are GMT -5. The time now is 00:00.
Find Us