PC Component power requirements on a KT3 Ultra-ARU: ANSWERS - At last

Question

G'Day Folk,
First, my PC specs are as below in my sig.
Second, I know this is an old motherboard, but I would like to keep it going, and make the best of it for another year or so. Any help would be greatly appreciated, and would help two other users!
Symptoms:
Minor stability and performance issues, mostly in games, simulators, or doing high resolution photographics processing. I bought three machines with similar specs in 2002, for my brother, father, and myself. Each has had some hard to nail down, intermittent problems. My brother's PC has had a new motherboard and processor after failure of the KT3, but still has some niggling problems. He also has an XP 2600+ running at 65C !
More recently I have been able to reliably reproduce graphics problems in Empire Earth II, Serious Sam, and Halo. Specifically, I can create the problem in an Empire Earth II game by running a saved game and looking at a specific spot on the map. The screen shows tearing, and eventually goes black, returning to normal dispaly when I move to a different part of the map. In certain Halo games I could cause the problem by looking in a specific direction. I assume this is because what is being displayed is using different or more graphics processing features, although it is not apparent what they may be from the content of the view.
Being able to reliably reproduce the problem allowed me to actually analyse the cause.
Diagnosis:
After upgrading all drivers, and trying everything I could think of, as well as everything I could find on the web, especially in this forum, I have narrowed the problem down to the power supply. The clincher for me is that when I create the problem the 3.3Volt power supply line (rail) drops to as low as 2.45Volts! The +5V line also fluctuates and drops as low as 4.81Volt. This was measured using MBM5 and MBM5 Log. The usual voltages reported by MBM5 at idle are +3.3V rail = 2.99 to 3.01 Volt, +5V rail = 4.92 to 4.95 Volt.
Okay, so the +5V rail stays in spec (just), but the +3.3V rail is out of spec (+/- 5%) even at idle. It should be at least 3.135Volt.
I checked the voltages with and without the problem using an analogue volt meter, as software voltage readings are often low. The volt meter is a little slow to respond to the voltage fluctuations, but did confirm that at idle the +3.3V rail was less than 3.1Volt (out of spec), and with the problem occuring, dropped at least to 2.8Volt.
As you can see below my power supply should be able to handle all I throw at it. Topower isn't the greatest brand, but it does receive "satisfactory" in reviews on Tom's Hardware and such. I suspect it (and my brother's and father's) has always been weak, although age, or more powerful games may be highlighting the problem.
Solution:
Get a new power supply.
Not so simple these days, particularly if you want to upgrade in the future, with the move to powering components using the 12Volt rail. I want a power supply that will power my current +3.3V and +5V hungry motherboard, plus future 12V requirements, if possible. So I am doing a Power Audit of my PC, hence . . .
Questions:
I have collected power requirements for most of my components in Ampere by supply voltage. However, details are hard to lock down. I'll jump straight into specific questions.
1. The Athlon XP 2100+ draws a maximum of 89.9Watts into the Voltage Regulator Module (VRM), which converts it to the CPU supply voltage of 1.75Volt. (About 51Amps. Ouch!) If this is sourced from the +12V rail as suggested by the AMD Athlon Desktop Builders Guide, then this would be 7.49Amp, and would not effect the +3.3V and +5V rails unless the total power capacity of the supply is being exceeded. However, the CPU power source was changed from the +3.3V and +5V lines to the +12V lines around the time of the XP2100+. I don't know what MSI did on my motherboard.
Can anyone confirm which voltage rail is used to power the XP 2100+ on the KT3 Ultra ARU motherboard?
2. I have found average power usages for motherboards of around 25 Watt on many web sites, but can't confirm the power used by the KT3. Does anyone know the maximum current (Amps) for each voltage rail from the power supply for this motherboard?
3. Memory power requirements also vary a lot on the web. I'm using 10Watt each on the +3.3V rail for two sticks of 512MB DDR Corsair. Can anybody confirm this, for the KT3? (10W per stick seems to have been the standard since 128MB sticks came out!)
4. I have a GeForce 4 Ti 4600 AGP graphics card. (Okay, it's not an MSI, but the power should be similar across brands.) There are several threads that suggest that this card uses lots of +3.3V and +5V power from the AGP slot. (Wonkanoby?) However, none give actual Amps for each rail. Anybody know?
5. In case anybody knows, I can't find actual power for an Audigy 2 ZS either. Any suggestions?
As modern power supplies tend to have reduced +3.3V and +5V capacity in favour of +12V, I need to be pretty sure of the actual requirements on these rails before buying a new supply. I could just "go and by the biggest Antec I can find and don't worry about it", but I might find that it has the same problems my existing one does.
All help greatly appreciated. Selection of a new PSU could fix three PCs, mine, my brother's, and my father's.
PS: My apologies to those I told that this was a great power supply. Well, it has great specs, and the problems observed couldn't be tied to it until recently. Bummer really.
PPS: Sorry for the long post, but it's an interesting, and important topic, isn't it?
UPDATE: See post on 1st March, 2006 for response from vendors and updated table of component requirements.
Here is a copy of my signature in case I change it in the future, just for context.
MSI KT3 Ultra ARU (MS-6380E V1.0),  AMI BIOS 5.7
AMD Athlon XP 2100+ Palomino 1.73GHz @13 x 133 FSB
2x Corsair CMX-512-3000C2 512MB 2-2-2-5-1T @333MHz
Leadtek GeForce4 Ti 4600 Winfast A250 Ultra MyVIVO 128MB (AGP)
Creative Sound Blaster Audigy 2 ZS
2x WD Caviar WD1200JB 120GB 7200RPM 8MB Cache,
          each drive enclosed in a Scythe Silent Box Heatlane HDD Enclosure
CD&DVD Plextor PX320A & Pioneer DVR-A09P
Topower PSU 470W PFC 3.3+5V=235W +3.3V/26A, +5V/47A, +12V/28A
mCubed T-Balancer Fan Controller,
          multiple quiet fans: Zalman, SilenX, Panaflo, Lian Li blower
Zalman CNPS6000-Cu & ZM-NB32J NB HS
~ 10-20C over ambient
Lian-Li PC-60 Case, WinXP ProSP2+

Answer 1

Try the link below, this will tell you what you need. After you added all you hardware and get the final power result add 50% to this and you will have the proper size P/S needed for your system. You can even make a list of future upgrades you want to do and that way you can see what P/S will work for you now in the present and what you would need in the future, just remember to add 50% to what ever total you add up.
For example, if the P/S calculator says you have a total draw of 279W then you would add 50% to this;
279+50%=418.5
http://www.extreme.outervision.com/index.jsp
Below I have pasted a piece that I made for determing P/S which may help you to;
Resets are a P/S issue and lock-ups are most likely due to your graphic card, with that said I will give you a table with which you can determine the proper P/S for your system and a little info just for info.
I must also add that never trust software to tell you your voltages, this includes the BIOs as the BIOs is just a piece of software. To properly check the voltage one must use a digi-VOM.
A 7200rpm HD draws around 20 watts, this 20 watts includes both the 5v & 12V rail.
HD and CD's generally are figured at 2 Amps per device, let’s brake this down some.
Spin-up: 12V x 1.3A + 5V x 650mA = 19W
Read/Write/Idle: 12V x 350mA + 5V x 700mA = 7.75W
Seek: 12V x 675mA + 5V x 725mA = 12W
Those would be typical for a 7200 rpm IDE drive. As you can see a HD requires more power at start-up then during actual operation. This is why sometimes a PC takes a few tries to start up before it will actually make a successful boot and once it boots to windows all seems well or sometimes a occasional restart, which would indicate a weak/ bad P/S.
Now to find the power used by the CPU you can check either AMD or Intel for the spec sheets on that CPU or you can follow this link that has tons of CPU ratings, CPU specs.
Some more basic mathematics… When a 12-volt circuit is drawing 10 amps, it is consuming 120 WATTS of electrical power. 12 Volts X 10 Amps = 120 WATTS.
This is the formula: P = E x I
P - Watt (power)
E – Voltage (electrical pressure)
I – Amperage (current flow)
Serial/PS-2 ports draw <35mA and if you have USB ports then they have a maximum of 500mA per port, again only if they are used- no use means no draw.
The PCI slots are allowed 5A of the +5V, 0.5A of the +12V and 7.6A of the 3.3V Max per slot, again that is if the slots are used. So if the serial ports, PS-2 and USB ports are being used you are looking at around 5A draw on the MB, which would be around 20 Watts.
So now we can add things up. (This is just an example of a basic system)
MB=20W
CPU= 60W, used as a norm.
HD=20W
CDRW=25W
DVD=20W
Graphic card=15W / newer GF4 and ATI 9000 and up= 35W
RAM 10 Watts per 128 MB
Network Card 5 Watts
Average per PCI Card 8 Watts
Total around 200W for this example.
Now this will fall on different rails and that is were things get tricky, because as you see in my above break down of the HD that a HD use's both the 12V & 5V rail. This is why it is important that the 12V rail be at least 18 Amps if you plan on having more then 1 HD and case fans. Then you have the 3.3V & 5V rails that need to be strong too, the 3.3v rail is actually not so important with newer DDR MB and today’s CPU’s as it is mainly supplying the PS-2 ports power as well as some device cards. Most newer MB use the 5v and 12v rails mainly to supply the demands of today’s devices.
Now this 200W is the bare min what is needed for things to run but in the real world you will want to add 50% to the 200W for your min P/S need, this allows room for spikes and heavy demands and a little head room to add hardware in the future.