Just under a year ago I purchased a Mains Power meter, as described in a previous post. It did cause me a little concern, because the voltage reading was quite high - up to 270-290 volts sometimes, instead of 240 or so, which meant it was way out of calibration. I exchanged it with another one which only read a little high - it’s reporting 254 volts as I type this. It means that it was probably reading around 20% higher than its actual usage. I thought I would give you some updated power figures, as well as show you the difference in consumption of the older Athlon XP system, compared with a newer, Core 2 Quad system that is its replacement.

For my system, I have updated it a little since the previous post. It now has a TV tuner card, 2GB of DDR2-6400 memory, and is clocked at 2.76GHz, a bit higher than previously. I have also scored a UPS, which the PC, modem, router and the backup server are now plugged into.

Some updated readings:

My Core 2 Duo PC:

On, running folding@home, screen on: 120W
On, idle, screen on: ~110W

These readings are really just estimates, as the power meter’s readings just keep fluctuating anywhere from 104 to 129W. It is also clouded by the fact that the UPS is plugged into the power meter, playing havoc with the results. when the PC is off, it can still show a power draw of around 70W, with just a modem, router and a standby server running off it.

Athlon System:

On, folding@home running: 150-160W
On, idle: 148W
On, idle, screen off: 130W

Core 2 Quad Q9300 PC, nvidia 7200GS, all at stock speed:

On, folding@home running: 130W
On, folding@home running, screen off: 106W
On, idle, screen off: 64W

You can see what a difference a few years and processor generations makes. I also recently purchased an nvidia 8600GT graphics card for the Quad box, to boost its folding output with the GPU2 client. I chose a relatively low-power drawing card, as I am conscious of how much juice it uses.

Core 2 Quad Q9300, nvidia 8600GT, all at stock speed:

On, folding@home SMP (CPU) client only running: 133W
On, folding@home SMP and GPU2 clients running: 143-151W

I was pleasantly surprised. The faster video card, running the folding client, consumed only around 20 Watts more power than an idle 7200GS. Quite a good result for an extra 1400 points per day in folding production, in terms of performance per watt.

While I was in the mood, I though I’d re-test the home theatre setup. The only difference here was that the video player has been unplugged, since it is no longer used.

Home Theatre:

All on standby: 16W
All on standby, HD Set Top Box on: 31W
TV and STB on: 146W*
TV,STB, receiver on: 120W

* The figure for the TV and STB on was curious. since there was no signal to the TV, it was displaying the blue background and power usage went up. Once a signal went to it from the receiver, usage dropped.