Hi,

I'm upgrading in a couple of days to an Athlon XP 2100, everything i have ordered has been delivered and i am now waiting on the case which comes with an atx P4/AMD 300w power supply.

However i think i have made a mistake in regards to the power supply. I have recently been browsing in other forums and noticed some people saying you need at least 400w to run an Athlon XP, Geforce e.t.c and that the power supply must have a combined power across the rails of at least 185w.

A quick look at my old 300w power supply says it only has a combined 160w.

The case and PS i have ordered is a Dabs value case from www.dabs.com .
Can anyone put my mind at rest and say i will be ok ? i'm hoping this case has a better quality power supply than my old one and be able to handle it.
I'm starting to sweat here as i'm already on a tight budget.

If you have a couple of Cdroms and a 7200 rpm harddrive or 2 I would go with at least a 350 watt. More than likely your new case will have a better 300 watt PSU. The 185 watt on the power rails is a good baseline.I have an 1800+ and a Radeon 8500 128 mb and 1 gig of PC 2100 RAM and 2 60 gig 7200rpm hardrives and 1 cd-rw and 1 dvd-rom and a floppy and hardware modem internal all running on a 350 watt Antec PSU

Since it’s already coming, I don’t think you’ve got much to lose by waiting and trying it.

Unfortunately, the symptoms of inadequate PSU vary from no Boot to quirky behavior and can very difficult to diagnose.

I’d probably go with 350-400 watts but if it is a good quality 300 watt PSU, you may do well.

It will work just fine. 350 would have been fine. Those extreme power supplies are not needed. 350 is more than enough.....

It's not so easy to just say, THIS will be fine, or THAT will be fine.

A standard system, with one hdd and one cdrom might well run fine on a quality 300watt PSU. But we like to add things, like top end graphics cards, and a second cdrw or DVD or second hard drive, and then there all those USB devies which all use power from the PSU. Not to mention extra fans for cooling purposes.

Run a temperature sening program all the time, like MBM (motherboardmanager which is free off the web). Then you will see how hot your CPU is, and if you add anything to the machine, you will know if the PSU is sturggling (MBM also shows voltages for everything and can be set to give warnings).

Truth is, if you can't be bothered with all of that, and you want peace of mind, get a 400 watt or higher. If you want to run your system as it stands and not really add much to it, run a 350. If you don't mind keeping an eye on the machine when it's working really hard, and you're happy running temp monitoring software, use your 300 if you wish. If I was building a PC for a friend, I would use at least a 350, for my own peace of mind.

I have 2000XP with 400watt.

350 is perfect. The large gaming machine manufacturers use 340 350 in their systems. The power supply issue seems to get a little out of hand. 400, 500, 600 just crazy.

I have never seen a system with a 350 in need of power. Not to say that it cant happen I have just never seen it. I have been using a 300 since the start on several machines all fully loaded and never an issue. I have a 400 in one machine again with no problems. Tis all good.

Go with 350 or 400. You can add items as you wish.

Issue resolved.

I use a 250 watts PSU (come with my old system)with an Athlon tbird 1,33ghz, 384 pc133, dvd, cdrw, gforce4mx, soudcard, 20gigs HD, ethernet card and floppy drive, and this for over 2 years without any problem. (i have replaced my video card since 1 year) I know it will be better with a 300 or 350 watts, but i dont have enough cash and my system run great.

I have an XP1600+, GeoForce2 MX/400, FDD, 2 x HDD, DVD, CD-R/RW, NIC, Modem, TV Tuner and SOund Card, 2 x 256 DD-RAM.

All driven by a little bitty 250W PSU!

QUALITY of product is sometimes a better measure than basic specification.