If a CPU is undervolted/underclocked, does this also influence peak power draw during boot, or is the BIOS setting applied a bit later on?

A 3570K has a 77W TDP but can be undervolted/underclocked to reach similar thermals as a 65W 3575S. But would there still be a good difference during boot?

My reason for concern is that I am looking at options using a 90W PSU (pico-style, very high efficiency). Could it power the following devices (note that there is no dedicated graphics card), with proper undervolting?

- 3570K
- Asrock Z77-E ITX (or similar if there are better options)
- 2x4GB (or 2x8GB) RAM
- 2.5" SSD
- 2.5 HDD

Just checked my main system (specs in sig) and at stock CPU speed the peak power draw I could see during POST was around 47W AC. This system is powered by a picoPSU-90-XLP and a 80W Meanwell brick. The CPU will not reach close to it's TDP even when stressed and the load is less than that during boot.

Usually it's when you start to add several HDDs that you will have to watch max load at POST.

Sounds great!

I know Intel motherboards are known for low power draw, too bad they don't have an alternative that support undervolting the CPU. My guess is that I can make up for the difference in motherboard efficiency by running the CPU at a lower voltage.

Hi,

I have same question, my plan is:
Antec ISK 110 with external 90W PSU
i3 3220
Gigabyte new released H77 wifi itx mobo
2x8 GB ddr3 1600 memory
1x2.5" SSD
1x2.5" HDD

to my applications, I3 is enough, but, as many other technical guys, I would like to pursuit something mini but powerful, so I am thinking if i5 is needed.

I checked Peuget System, i5 3450s and i7 3770s, 65W tdp cpu are supported, but when I have read the tomhardwares review to i5 3570k, 3570s, 3570t, 3570, I found 3570k even consumes almost less power than 3570s, so, my present question is:

if 3570k could be supported by ANTEC ISK 110 with 90W PSU?