Following concerns that some power supplies will not function properly with Intel's upcoming Haswell processors, Seasonic has joined in confirming which of its current models will work with the new chips.
The issue stems from Intel Haswell processors having a new ultra low-power state, called ZERO-load, that can cause some power supplies to fail when the CPU tries to return to a high-power state.
In response, power supply manufacturers are now starting to confirm which of its models will be compatible with Haswell CPUs - the answer is most of them, assuming they're reasonably high-end.
recently outlined the issue, saying: "Even if the sleeping CPU is the only load on the +12V rail, most power supplies can handle a load this low. The potential problem comes up when there is still a substantial load on the power supply's non-primary rails (the +3.3V and +5V). If the load on these non-primary rails are above a certain threshold (which varies by PSU), the +12V can go out of spec (voltages greater than +12.6V). If the +12V is out of spec when the motherboard comes out of the sleep state, the PSU's protection may prevent the PSU from running and will cause the power supply to "latch off". This will require the user to cycle the power on their power supply using the power switch on the back of the unit.
Seasonic is the latest manufacturer to list which of its power supplies do not suffer from this problem. They are as follows:
- 650 W
- 750 W
- 850 W
- 1050 W
- 1250 W
- 660 W
- 760 W
- 860 W
- 1000 W
- 1200 W
This leaves the following model's as non-certified:
520 W, 620 W
The full list of Seasonic power supplies can be found here
Other manufacturers to confirm compatibility already include Enermax
and as previously mentioned Corsair
Will you be upgrading to Haswell? Does it look like you'll need to invest in a new power supply? Let us know in the forum.