Pricing-wise, this seems to be on a par with the AX Gold series, although the latter seems to be Corsair's premium product. Doesn't that rather price the new HX out of the running? Or does the new HX effectively become “top dog” replacing both HX and AX?
AX-series is still the better supply out of the two in terms of pure performance. This one costs around £15 less and, for what it's worth, has a few captive cables, whereas the AX does not.
Tarinder, with all due respect, I think you need to think a little more about how these things might be engineered. For example:
“We loaded the supply with 425W for five minutes and then reduced this to 100W, a figure where the fan should be switched off. The unit took approximately 90 seconds to determine it was safe to switch the fan off completely.”
What makes you think fan control should be dictated by wattage? I think it is done by heat. After loading to 425W for five minutes, you'd expect the unit to be hot for a while, even with the fan running. So the 90 seconds is simple the time it takes the fan to get the unit under a safe threshold temperature-wise.
“Likewise, running from 100W up to 425W doesn't initiate an instant-on fan; the supply takes a while before kicking the 14cm fan into action.”
Likewise, there will be a lag in temperature increase when you load the unit up.
Ultimately, the fan isn't protecting against higher (but within spec) wattage - that's what the PSU is designed to output! It's protecting against heat, which could be dangerous. If it ramped up based on Wattage, it could be regularly spinning up and down with certain programs / volatile power needs, which would be annoying. By reacting to temperature, it means spin up and down transitions only occur when necessary and less frequently overall (preferable).
At least I reckon that's what's going on.
Noli
Tarinder, with all due respect, I think you need to think a little more about how these things might be engineered. For example:
“We loaded the supply with 425W for five minutes and then reduced this to 100W, a figure where the fan should be switched off. The unit took approximately 90 seconds to determine it was safe to switch the fan off completely.”
What makes you think fan control should be dictated by wattage? I think it is done by heat. After loading to 425W for five minutes, you'd expect the unit to be hot for a while, even with the fan running. So the 90 seconds is simple the time it takes the fan to get the unit under a safe threshold temperature-wise.
“Likewise, running from 100W up to 425W doesn't initiate an instant-on fan; the supply takes a while before kicking the 14cm fan into action.”
Likewise, there will be a lag in temperature increase when you load the unit up.
Ultimately, the fan isn't protecting against higher (but within spec) wattage - that's what the PSU is designed to output! It's protecting against heat, which could be dangerous. If it ramped up based on Wattage, it could be regularly spinning up and down with certain programs / volatile power needs, which would be annoying. By reacting to temperature, it means spin up and down transitions only occur when necessary and less frequently overall (preferable).
At least I reckon that's what's going on.
FYI: The fan is controlled by measurement of load and temperature, depending on which is most critical.
IIRC, if the PSU is only running at room temperature (~25C) the fan isn't going to kick on until 30 to 40% load. Then at higher temperatures, naturally the fan will turn on sooner. Naturally, the adverse it true as well. If the load is decreased, even if as low as 100W, the PSU is going to have to cool back down considerably if it's 30 to 40C inside before that fan shuts back off.