power supply question concerning AMD mother-board and chip upgrade

Pugwash

i am thinking of upgrading a very old pc in my home ,a gateway p-133 to be exact.

it has lay inactive for about a year so i want to change that and make it useful once more.

it has a nice, large case wich can house 3 hard drives, has 7 expansion slots, four CD drive slot spaces and two floppy drive-sized spaces.

the power supply is 230W so i was wondering what would be the highest AMD processor that would run safely in this case.

the PC would have 48mb SD-RAM, a voodoo3 2000 agp card, a 56k modem and a 2.5GB HD at the time of installation of an upgrade.


would such an upgrade be possible i.e. would more fans need to be added, a new case, would there be enough power to go around for all the components?.

phaxx

My PSU is 250w, using a Duron 700, Abit KT7, two cd drives, two hard disks, no problems.

JustHalf

You probably have an AT PSU, so you won't be able to use that. This means you'll need a new PSU.

Gateway boxes tend to be of non-standard sizes, so I'd wager you also need a new case for the new motherboard (which I'll assume you're getting, since you seem to want an AMD chip; and you probably don't mean a K6).

This also means new RAM, and I'd recommend a new video card and hard drive (definitely the latter).

Which is pretty much a brand new machine.

Gerry

Disregard the last post.

The power supply is more than likely atx. You can check this like so: does your computer fully power off when you shut it down?

If it does, its atx.

The gateway tower is a pretty nice case, it should take your new motherboard with no problems.

As I informed you on irc, the 230w psu should be good enough for a 1 gig tbird.

Pugwash

thanks for the reassurance gerry but what else will i be able to run with it?

a 1ghz would take alot of power, would i be able to run the other stuff mentioned on me previous post?

thanks for your feedback lads

BTW its a desktop case and according to your diagnosis Gerry, it is an ATX

Fidelis

Sorry to butt in on your thread Pugwash, but I've more or less the same question.

Would a 300w PSU do for an 1800xp chip ?

Gerry

You should be able to run all that stuff of it as well, they won't be drawing very much power.

Fidelis, a 300w psu is fine for an xp 1800+ .

Boston

well it depends, normally for the adverage user gerry would be absolutly right, but as you all know, the cpu only uses a fraction of your power supply needs, if your planing to run somethign thast goign to be on 24/7, have 2 cd roms (dvd, cd rw) a cuple of hard drives, and a high powered graphics card and sound. then id suggest a 350watt.

but this is the most debatable thing ever when it comes to pc's

for a starter, some (cheaper) 300watt psu's only bang out 250-270 in reality. while decent ones tend to give you that little bite extra.

basically, what Pugwash whats and a 1800xp, get just a decent 300watt.

as for the gateway cases, they are unstandard (but dont worry you still be able to install and amd board)
and the psu's that comes with most are AT they simply wont work with new boards. but theres a simple way to avoid a fight here, the at main power cable is some what shorter at the base then the atx, simply find a picture of the motherboard you want, and compare the power slot on the board to the cable coming out of the psu, you should be able to tell at a glance weather or not it will work.

TacT

I have a 350w psu running my pIII 1gig 2 hdd, 1 cd-r and all my fans

It's really a question of how many motors/fans/engines are coming off the psu.

I'd go for a 350w for the xp1800 myself because you never know when you might start adding more devices in there .....

Some people go so far as to have one psu for fans and the other for mobo/gfx/cpu/cdr/dvd drive etc. which is what I'll be doing for my mod.

Currently I have a slot 1 athlon 750 (anyone know if the multipliers on these are locked/unlocked) it's one of the early models.

It's going on a via k7...with a tnt2 32meg. I still need ram/psu/hdd's/cdr/dvd drive and a few other bits, anyone got some reccomendations/ideas they'd like to throw at me.

renton has a nice car radio he converted to work with an atx psu I'm wondering about a nice digital display for thermal sensors etc to go underneath/over this.

It will be running win2k pro/server yet to be decided.

Boston

well i dont think he will be running to many fans in a gateway case, though there is a sapce for a 80mm delta just over the cpu at the back of the case if you wanted to add one, imho thats the most important place.

Gerry

I built a machine a while ago with a 1 gig athlon clocked to 1.4 @ 1.85 volts (obviously drawing a lot of power), 512 mb ram, 3 hard drives, 2 of them 7200rpm. Geforce3, sblive, dvd and writer.
All this ran perfectly off a 250 watt power supply. While I was building it, waiting for the case to arrive, I ran it with no trouble from my 235watt psu's. This was on under full load for a few days, still no crashes.

350watt and 400watt psu's are great, but a decent quality 300w is all you will ever need.

tactical anni, fans draw around 2-4watts each from the 12volt line, a line that has only the hard drives and cd drives drawing 15-30 watts from it (except on p4 machines) So you could string a fair few fans off any psu before running into any problems.

Dual psu setups are only necessary if you are doing water cooling, especially with pelts.

TacT

Thx gerry. I was never sure of the exact quantities of power needed so I always played it safe and seeing as I had an old 230w psu and decided to get a 300 i decided I'd go for a 350 cause I never know how much I plan on adding

Saruman

Firstly Pugwash no matter what you need a new psu.. 300 watt will do fine but its not important.. as long as its 12A or more.. most 300W psu's are which is why people say an Athlon needs a 300W psu.. even though its not exactly true.

AS for the case.. whch case is it.. Gerry is right about shutting off automatically though its not the best way to check since you may have power managment dissabled in which case that function will also be dissabled.. best way is open it up.. an ATX system sis simple.. there is a single connector from the psu to the board and the only way to turn on the psu is from the board itself. An AT usually has 2 smaller connectors on the board but can be turned on via a switch on the psu (some ATX have switches but they are only cut off.. you still need to turn on from mbd). Obviously you want have a problem opening the case to take a look if you are going to upgrade the whole thing!

sisob

Originally posted by Gerry
I built a machine a while ago with a 1 gig athlon clocked to 1.4 @ 1.85 volts (obviously drawing a lot of power), 512 mb ram, 3 hard drives, 2 of them 7200rpm. Geforce3, sblive, dvd and writer.
All this ran perfectly off a 250 watt power supply. While I was building it, waiting for the case to arrive, I ran it with no trouble from my 235watt psu's. This was on under full load for a few days, still no crashes.

/B]

unfortunately psu's arent intelligent devices and if they are overloaded they will still try their best. if your pc is underpowered it will probably just damage the hardware and the psu will start whining like and old fridge

300 watt is the way to go

Gerry

If overloaded they will generally produce unstable power, causing the machine to crash. Guess what, the 250w psu didn't whine after 4 months.

I was just giving an example, and I do agree that 300w is the way to go, my point was that 300w is enough even with a highly loaded machine.

Saruman

By the way Pugwash.. great idea for you.. the case i think you have should have a large open space above the psu. Its generally for a few more hard drives... if you are worried about power its easily sorted.. rip a hole in the case and stick an old AT psu in there and use it for powering up your hard drives/ cdroms etc especially the more powerfule ones that eat more juice.... takes the strain off the ATX psu and leaves it mostly for the board and chip.

PPC

All Athlons over 1.2 need a 300w to run safely. I think Soyo boards wont run without a 300w as a saftey feture.
I had a 250w on a 1.2@1.38 and 12 fans and it worked.
I've recently upgraded to a 300w for safety though.

Mountjoy Mugger

Originally posted by PPC

I had a 250w on a 1.2@1.38 and 12 fans and it worked.
I've recently upgraded to a 300w for safety though.

12 bleedin' fans!!??? :eek:

JustHalf

And one of them's an 80mm delta, for heavens sake. The whine must be unbearable.

Pugwash

can you over power a pc?

e.g. would a 340W PSU damage a p1 crap pc?

Boston

No you cant damage a pc, but remember power here is far more expensive then the uk or america, do you really want a system and the bills to match that requires 350watts

just something to keep in mind

PPC

No their just normal fans.
3x 80mm Delta Screams (48Dba) and 1x 120mm YStech (45Dba)
Plus some others i can't hear

PPC

Originally posted by Pugwash
can you over power a pc?

e.g. would a 340W PSU damage a p1 crap pc?

No cause an Athlon single processor board can only take upto 450W i think (please correct me if im wrong) anything over won't work.

Gerry

right,

An electronic component draws as much current as it needs. Therefore your pc only draws what it from the psu, nothing more.

So,

1. A high powered power supply will not force loads of juice through your pc, but if your pc needed loads of juice, it would be able to deliver it.

2. Power supplies do not work at their full output all the time. Most machines will never draw the full amount of current out of the psu. Also, obviously enough, your machine draws more power if it is doing more work.

So, having a more powerful psu than you need will not drive up your electricity bill.

It follows from what I have said above, that there is no "maximum" wattage power supply that any motherboard can handle, you could run a machine off any psu that provides at least the minimum current. For example, a 3 megawatt psu.

Hope this clears things up.

Inspector Gadget

The voice of reason strikes - good man Gerry!

The whole point of a modular power supply is that it supplies DC power at a number of closely-regulated voltages (commonly +3.3v, +5v, and +12v as well as negative flavours of same), up to a rated peak currents for each of these voltages.

Under certain circumstances - examples would include a period of high CPU usage, or a period of dense hard/optical drive activity, or a 3D game, or any/all of the above, then the current demands of the computer will increase, sometimes dramatically. If the level of current demand at any of these voltages meets or exceeds the rated maximum output of the PSU, it will struggle to deliver all the current that is being required of it; to do this within it's maximum rated power level, the supplied voltage(s) will drop - this can cause crashes, and sometimes hardware failures.

On the other hand, if your PSU is able to supply all the current you need, including when demand goes up as I've mentioned, without straining, it can maintain proper voltage regulation (ATX specs allow for 5% deviation either way on the voltages mentioned above), and all is hunky dory.

Does this help?
Gadget

yellum

oh fer ****s sake lads.. I have to clean this thread now.

JustHalf

Ah well.

Pugwash

one thing i am rightly stumped on is how much power a moniter would demand.

whats the differance in power demand between a flat screen and a regular cube-like moniter


and another thing, is there much of a power demand differance between a 7200rpm HD and a 5400rpm, IDE that is.

bonkey

Heh - thats the one thing most people didnt mention...

Under no circumstances should you ever run a monitor off a "pass-through" connector like the ones on older pcs. Ok - maybe not under *no* circumstances, but you really will strain your power - remember that design died in the early Pentium days, as people started needing more power for their components, and using larger monitors.

Besides, for the sake of one kettle-lead and a socket, its not worth the risk

Flat-screen are more power-conscious, AFAIK.

Oh - and in terms of AMDs *needing* certain power, I run my machine off a 250W PSU - thats a 1.4 TBird, GeForce2 MX, HD, DVD, CDRW, FD, USB Modem, on an ASUS mobo, using one standard (40mm ?) fan on my heatsink and a second larger "blower" mounted on one of the expansion slots.

No power glitches, no problems. Sure, in theory, my 250W may not last for the next 100 years, but thats not the point. THe point is that you have a *free* usable power-unit today. Which means that you can keep costs down. You *may* want to replace it if it ever seems to become unstable, but for now it should do fine.

jc

halfab

Nope no damage .. the board will only take what it needs , if thats only 70w then thats what it will take..



l8r

halfab

Gerry

erm bonkey, if you open any power supply with a pass through connector, you will see that the mains current does actually pass directly from the input connector to the output, without going through any of the rest of the psu. Therefore it doesn't draw anything from any of the rails on the psu, so it isn't going to affect the rest of your pc. As for it dying in the pentium days, well the design was much more useful with at psu's, since turning off your computer switched off your monitor as well, whereas with an atx psu, if there is no switch on the back of it, there is power going through it all the time. It is still useful for saving plugs though.

Pugwash

just need to get this straight...

is the socket circled in blue in the pic attached an ATX socket?

PPC

yes

bonkey

Originally posted by Gerry
erm bonkey, if you open any power supply with a pass through connector, you will see that the mains current does actually pass directly from the input connector to the output, without going through any of the rest of the psu. Therefore it doesn't draw anything from any of the rails on the psu, so it isn't going to affect the rest of your pc.

Oops. My bad. Sorry for misleading anyone.

jc

Gerry

ah don't worry about it, I'm just being my usual pedantic self

po0k

in answer to Pugwash's question about power usage of drives, it's usually written on the spec sheets, i e max wattage at spinup, opening/closing CDROM drawer, etc.

Power(Watts)=Voltage(Volts)xCurrent(Amps) for DC.
For AC it gets slightly more complicated

Hey, here's an idea, anyone want to help mod a 1960s-era Russian Fission Reator core into a Super-conducting pile?