I'm having a restart problem with my athlon xp +1700

I have one main question

1.) does an athlon need more than a 250watt psu?

I've always been told they needed preffarably 350watts to 500watts is this true?

A processor isn't what draws the most power. Your needs are based on the total configuration of the box -- drives (hard and removable media), memory, fans, cpu and add on devices (pci and agp cards). 250 watts should be enough for a single hard drive, single cd-rom system. However, there are TWO ATX power standards and you need to mark sure your PS meets those needed by AMD. The easiest way to do this is to look for "AMD Athlon Approved" or similar verbage with the PS documentation.

A general rule of thumb for processors is if the cpu speed is over 800mhz you should have at least a 300 watt powersupply. It will run on less, but it can be unstable.

The newer cpus do take more power than older ones. 300 watts should do fine unless you have multiple harddrives, cdroms, etc., or one of the newer videocards that really suck power.

My computer runs a 1.5 Ghz ps with a 250w psu with no problems. Like the others have said, though, it depends on your setup. As a possible rule of thumb, I've heard you take the power requirement of the cpu plus 80% of the total power requirements of the rest of your components, and get a psu that can handle that easily.
From www.tomshardwareguide.com , their tests showed that many cheap psu's would not actually produce as much power as they were rated for. So if you have a cheap 250w psu, you could definitely be having some problems. 500w is overkill unless you're running multiple cpus, RAID, high end vid card, etc.

I've got a whopping pile of stuff in my case (I'd list, but then I'd feel like I was on the [H]ard forums ) all running off a reasonable 300W PSU. The point isn't so much how big a PSU you get, but how nice of one. Check THG and see what brands are listed as pretty good, then buy from that brand.

I just had a friend have his PSU short (I mean smoke and burn kind of short), and it killed everything else in the case (hdd, m/b, video, sound, dvd). Luckily, it was a couple years old and wasn't a huge loss (data excepting).

Wattage numbers are like processor MHz: only vaugely related to their performance. Good stuff is better than fancy stuff.

Thats rubbish mate!

The wattage of CPU's has gone down dramatically when you compare a Thunderbird to an XP or even a Barton.

The Thunderbird 1.4GHz was the CPU that drew the most power (and was the hottest too) of all AMD CPUs. The XPs were all cooler and drew less power.
This is true of the Barton's as well, all the way up to the Barton 3200+. I think that one has almost the same power that the old T-bird had.