Haswell Could Have Compatibility Problems With Older PSUs

Yesterday, we gave you a full roundup of all the rumors that we have reported regarding Intel's desktop lineup of Haswell CPUs. In the meantime, yet another rumor has surfaced. According to VR-Zone, a number of power supplies will actually not be able to support the Haswell CPUs, not because they cannot deliver enough power, they cannot deliver a low enough level of power.

While the Ivy Bridge CPUs had a minimum power consumption of 0.5 A in a C6 or C7 state, the next generation of processors would require only as little as 0.05 A, a 10x reduction. The problem is that a number of older or lower-quality power supplies are unable to deliver such low loads at stable voltages, meaning that the system could crash due to unstable voltages when in C6 or C7 state.

Fortunately, there is a solution. Users with problems could simply go into the motherboards' BIOS interface and disable the C6 and C7 power states. However, this would lead to higher power consumption. Fortunately though, most modern power supplies shouldn't have issues with the low power draw. A number of manufacturers are already advertising power supplies that have perfectly stable voltages even down to 0 W, among which is Enermax.

Niels Broekhuijsen

Niels Broekhuijsen is a Contributing Writer for Tom's Hardware US. He reviews cases, water cooling and pc builds.

  • webbwbb
    Good. This will hopefully get people to throw their fire hazards (that is how I officially refer to cheap power supplies when talking to customers).
    Reply
  • pbrigido
    In other news: If you are building a new system with a Haswell CPU, use a new power supply.
    Reply
  • ccovemaker
    Stable voltage at 0 watts....ummm interesting science.
    Reply
  • Rune Olsen
    Since you don't need R i guess you don't need I either. Magnificent!
    Reply
  • Rune Olsen
    Since you don't need R i guess you don't need I either. Magnificent!
    Reply
  • Rune Olsen
    Since you don't need R i guess you don't need I either. Magnificent!
    Reply
  • Rune Olsen
    Since you don't need R i guess you don't need I either. Magnificent!
    Reply
  • Rune Olsen
    W00t, something is terribly wrong here with my single post
    Reply
  • maui67
    It will be interesting to see how off-the-shelf manufacturers handle this, especially in inexpensive machines. They will need to start putting quality PSUs even in the low-end machines. I am sure the big boys like Dell and HP will be fine, but what about E-Machines and the such?
    Reply
  • halcyon
    10740842 said:
    It will be interesting to see how off-the-shelf manufacturers handle this, especially in inexpensive machines. They will need to start putting quality PSUs even in the low-end machines. I am sure the big boys like Dell and HP will be fine, but what about E-Machines and the such?

    PSU oems will just start making cheap units that support the new CPUs. There will be enough demand to justify it.
    Reply