Via Vs Intel Power Consumption

Background

After some discussions on various forums online, I decided it was time to prove or disprove that Via CPU’s were well worth the money and worked nicely to provide a low power systems and that they were the only choice for a low power system.I myself was keen to work this out as I don’t like using a lot of energy. Yes, I leave my main computer on 24/7 to run distributed computing projects and I find that fine as I can justify leaving it on (and I take power saving measures elsewhere, such as using energy saving bulbs and keeping anything I don’t need turned off)

So when I built my webserver and home server for backups, I went for the Via CPU option and mini-itx motherboards. This combination gave me a small PC that drew not a lot of power at all. I even used a compact flash to IDE converter to boot the machine off a low power compact flash drive. This setup proved very successful. It ran my server fine with a few minor slowdowns when the server was busy with me downloading new packages or generally using the server as it was only a 533Mhz CPU. Overall I’ve been happy with it, especially knowing I was much less power than if I was using a moderrn day Intel or AMD chip.

Well that was until I saw forums saying I might have made a mistake…

Testing

Anyhow, this led me to do some testing. The forums were saying a modern day Intel chip (Core 2 Duo and variants) could most likely give a Via CPU a run for it’s money on power consumption and it would even run rings round it performance wise. I didn’t doubt performance wise an Intel chip would beat a Via CPU but I was very sceptical that it could compare power wise.

So I acquired a Kill-O-Watt meter and decided to compare two systems, my Via CPU based server and my Intel Core Duo laptop.

Machines

So I set about testing. For comparison, the machines are the following…

Fujistu Siemens Amilo Pi1505 Laptop
Core Duo 1.6Ghz T2050
80Gb HD
1Gb RAM (DDR SODIMM)
Wifi On
Screen On
Onboard GFX
3xUSB2 ports (nothing plugged in)
No battery plugged in
Dual boots Windows XP and Ubuntu Desktop

My hand built server
Via Samual 533Mhz CPU
512Mb RAM (2 sticks of 256Mb SDRAM)
4Gb Compact Flash drive
8Gb USB drive plugged in
USB2 PCI card
Boots Ubuntu Server

Well anyhow, those are how the two rigs faired up. Obviously the the laptop outperforms the server on CPU inetensive task majorly, being as it is a dual core CPU and having 3x the clock speed.

So I tested them under two conditions, idle (leaving system as it is) and letting running Prime95 to get the CPU to 100% and thus reach full load, drawing the most power. There maybe more ideal ways of getting 100% load but this seemed easiest to me and cross platform (which due to the server’s operating system, thats what I needed)

The results I got startled me.

Results

So I tested them. And it wasn’t until after I’d tested them both, I realised I’d tested the laptop whilst the screen was open. Thus it would be drawing more powerto power the screen. So I reran the tests for the laptop, allowing the screen to turn itself off via power saving before I took a reading.
The results are shown in the graph below.

As you can see, the Intel CPU manages to draw about the same power as the Via throughout the test but at 100% load does have a higher power draw. As soon as the screen was turned off, the power drain dropped remarkably and approached the same kind of power draw as the Via CPU system. At Idle, the Intel system drew much less power than the Via CPU.

Conclusions

From these results, clear conclusions can be drawn. A modern Intel chip such as the Core Duo can be an acceptable CPU for a low power system. Other low power components will of course be needed to keep the system at a low power level as well but it’s entirely possible.
The laptop I used would obviously be using power saving components such as a decent low power mothboard and disc drives, which is what I would build a low power system from anyhow.

So as shown, a low power system with some serious CPU power can be made out of a modern Intel chip. Unfortunately this means I will probably be in the market for a low power Intel chip and some low power components to go with it!!
This power consumption doesn’t take into account any underclocking or undervolting of the CPU to get it to use less power and considering the overclockability of the modern chips, it makes sense that they should be able to underclock and undervolt quite a bit if lower power is needed.

Hopefully that’s cleared up some myths about low power machines. I know it’s certainly helped me.