I've decided to replace my ancient P4 2.4 computer, not least because it draws 125w at idle (excluding monitor).

Ideally I'd like to get that down to a maximum 80w, and I'm thinking of using the following:

Intel Core 2 Duo E7200 or E8400
Gigabyte GA-EG45M-DS2H mATX m/board
4 Gig Corsair DDR-2
WD "GreenPower" 500gb 3.5" HDD
Antec EA-380 380W EarthWatts PS

Is this likely to give me the results I want? Suggestions on alternatives welcome, though I'd prefer a Core 2 Duo based machine and a board with eSATA on the back panel.

Most of the time the computer will be used for low power tasks, web design, email, surfing, etc, but I do need at least the equivalent of the P4 to run Photoshop for about an hour a day. Will the E7200 be adequate, or should I go for the E8400? I haven't been able to find figures of the difference in watts between these two cpus, but I've read the E8500 draws significantly more.

Is there any advantage in using 2Gig memory modules rather than 1Gig?

Thanks

Is the only reason you want to upgrade is to get lower power consumption? Because if so then upgrades make no sense. The money you'd spend getting the lower power consumption would take years and years to get back through reduced electricity bills.
What do you use your Pc for that your current system feels inadequate?

Even the current dual-core Celerons are faster than that P4! You could save yourself $40 and just get an e5200. Or save even more and go with an AMD processor -- the motherboards are cheaper for the same features. Any X2 will dominate a 2.4GHz P4 and still use far less power.

Thanks for the concern FartingBob, but while the power consumption was the deciding factor it isn't the only one. As per the initial post, this is now a very old machine and it's starting to show it. Not only are one or two components nearing the end, it is also struggling to run current versions of some programs.

Plus it won't take me all that long to get my money back. I have a 2.5KWh solar PV system and get paid a very healthy premium on all the power I upload into the grid. Assuming the new computer uses 100w less (including a LCD monitor), I figure it'll take about 28 months, based on current pricing which is almost certainly going to rise if our government introduces a promised carbon cap and trade system in 2010.

jessekopelman, thanks for the comparisons between current CPUs and the P4. It's hard to get an idea of how they compare from raw benchmark figures.

I haven't had much luck with AMD products in the past, hence the reluctance to consider a X2 based machine. Maybe I've just been unlucky.

Any thoughts on 1Gig versus 2Gig DDR2 memory modules?

I'd say 2 DIMMs is better than 4, if only for flexibility's sake. You occasionally hear about MB with finicky slots and having to move the DIMMs from 1 and 3 to 2 and 4 to get dual channel to work. You may one day have reason to upgrade to even more RAM, but not to a new MB (although seems very unlikely if you are starting with 4GB). I'd think 2GB DIMMs would have a slightly longer useful life as components in future PCs. Also, airflow is going to be slightly better for the RAM with empty sockets between the DIMMs. I've yet to see any pricing that would make me go with 4X1GB instead of 2X2GB, but if you've found a really great deal there is no major downside.

That very much depends. I worked out my Seasonic PSU will have paid itself back by the time it's out of warranty, given how much time my computer spends switched on.

But if you're going to upgrade anyway, you may as well get more efficient stuff. Not that it's difficult to get something more efficient than a P4... if you can shave off 50W you could be saving £100 or more over the next four or five years, maybe doesn't sound like much money for the amount of time, but it's a significant discount on a new PC when you add it up.

I would go for the biggest Caviar Green available - 1TB. The power specs are excellent, and if you fill your 500GB drive (torrents anyone?) then you're up for a second drive, and two green drives will be like having one ordinary drive power consumption wise - might as well go for the best MB/watts ratio you can get.

The WD10EACS is probably the best MB/watt/$ bang for buck at the moment - the newer WD10EADS is about $50-60 more expensive in Oz because it's newer and came out when the dollar was lower.

I'd be amazed if I ever used more than 500Gb in my life. Currently sitting on less than 40Gb...
Personally, I'd go for a laptop drive for super low power consumption, otherwise the Hitachi P7K500 someone else here recommended me looks very attractive. If you want a lot of space for media you'd be better with an external drive, and only turn it on when you need it.

I have about 230 Gig worth of data on my current computer, bgiddins, so I figure 500G should be adequate this time round.

I do a complete backup to Ghost image once a week keeping the last 2 images. Currently, they are on a second internal drive, but to save power this time I intend installing a 1TB WD drive in an external enclosure and powering it up only when needed. This is why I want a board with eSATA.

Moon GT, I did consider a laptop drive, but if the one in my, admittedly low spec laptop is any guide, it would be too slow. According to WD's data, the Greenpower drives are pretty efficient drawing only a handful of watts more than a more expensive laptop drive. I figure putting the money saved toward replacing my current 21 inch CRT monitor with a 22" LCD is going to give me far more energy saving bang for the bucks.

The Hitachi Travelstar 7K200, according to Storage Review, rivals many desktop drives for performance. It certainly beats my old 80Gb Samsung for speed.

The Hitachi P7K500 is a desktop drive, and not expensive at all, and with idle power consumption comparable to the WD, although they only go up to 500Gb. The Western Digital is certainly price competitive at 1Tb though.

Tom's Hardware compares the two in this article:
http://www.tomshardware.com/reviews/ene ... 44-11.html

A bit off topic, though I want to remind you that Antec switched EarthWatts supplier to Delta several months ago. Delta's acoustics remains a mystery on SPCR forum for the time being.

Thanks for the heads up on the Hitachi P7K500, Moon GT. It seems to have a slight performance edge over the WD at very little if any cost energy wise. It's the same price as the WD too.

Hello,

I may have missed it, but what video card are you going to use? To keep the system under 80watts, you will have to choose wisely...

Apparently, this is true of all models except the 380w.

I'm hoping the X4500HD integrated into the GA-EG45M-DS2H will be adequate. I know Intel comes a very distant third to nVidia and AMI, but I have little need for 3D.

However, if it isn't up to the job then I was thinking either a ATI HD3650 or nVidia 7300GT based card.

I built a system the other week with a Geforce 9600GT, it idled at 72W at the wall.

That would be great since Antec often gives discounts on their PSUs, and 380W is pretty enough for most people.