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POWER!

by UnWritten7 / December 17, 2004 1:53 PM PST

I recently posted about my computer over heating(or so I thought it was).The CPU was running between 113F and 133F, the MB between 90F and 100F. Some told me it was a bit high and others said it was fine. One person said it was the power supply and another said maybe my CPU wasnt compatable with my MB.

I checked it out and my CPU type was compatable but only up to 2.4ghz(Intel Celeron)and I had a 2.8ghz.So I replaced the CPU with a P4 2.8Ghz with HT which is supported by my MB.

Now instead of running at 113F at startup it runs at 123F. I know since it has HT it would run at a higher temp, but any idea if this is normal? Also if Im not currently having any power problems(with 300W)should I upgrade to 400w or higher? What does the power supply have to do with the MB and CPU heat?

Look at my profile if you have questions about my system specs.

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Interesting...
by Scott Swinyard / December 17, 2004 3:57 PM PST
In reply to: POWER!

Do you have the proper heat sink and fan on your cpu?

Make sure the sink is large enough and the fan powerful enough. Make sure your case has adequate ventilation to let the it's fans move enough air to bring in cool air from outside and move the hot air the components generate out. Is it very warm in your house? The warmer the environment your computer is in, the harder it is to keep it cool.

If you have a properly running system with the proper cooling systems in place and a well ventilated case, there is no reason that you should not be able to keep the temperatures down where they should be. Make sure you dont have a bunch of cables or anything else restricting the airflow around your processor.

Make sure the cpu fan is clean and turning freely.

Find out what rpm it's supposed to be running at and check to make sure its running fast enough. There should be an indicator in your bios. Make sure the heatsink is clean. Too much dust buildup can keep cool air from getting to it and keep heat in too.


Ditto chipset sink, and fan if it has one.


The power supply has a fan in it. If that fan is not working properly it could have an impact on cooling to varying degrees depending on how major of a part it plays in cooling your system. It also generates heat of its own that can raise the temperature inside the case. That heat needs to be removed.

Is it excessively warm? Make sure the power supply vents are not blocked. Check the fan and make sure it's clean, not blocked and turning freely at the proper speed.

Keep your computer in a cool place.

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A cool well ventilated place...
by Scott Swinyard / December 17, 2004 4:02 PM PST
In reply to: Interesting...

and make sure the case fans are not butted up against a wall.

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Fans
by UnWritten7 / December 18, 2004 1:39 AM PST

I have one intake fan from the front of the computer running air in,a outtake fan running hot air out and an extra case fan blowing air towards the center of the MB. The cpu fan and heat sink were made for a P4 and are running at top speed.I used thermal paste when I put the CPU in. All my fans are running the speeds they are suppost to and everything in the case is brand new so there isnt any dust build up.The case fans all are Cooler Masters 80x80x25mm 2500rpm and the CPU fan is a Zalman CPU fan with heat sink 109x109x62mm 2400RPM.I know its a bit slower but since its a bigger fan shouldnt that balance it out?

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Well I'm no expert...
by Scott Swinyard / December 18, 2004 6:17 AM PST
In reply to: Fans

hehe. Man I gave it just about everything I had when I told you that stuff, but I would think that a fan the same size as the sink would be best at the highest rpm you can get. My Intel cpu fan only runs at 3xxx rpms, but is actually nowhere near the size of the sink. Is your fan\sink rated for a p4 of the speed you have?

Heatsink\fans for slower p4s may be less capable?

I had a problem with heat too that seems to have been related to the temp in my apartment, but my chipset temp was higher in relationship to the cpu than yours leading me to believe your problem could be more specific to the cpu area.

Are you checking these temps with a program or with the bios? If a program, check it with the bios, and if it's different go on that.

-Is your case p4 ready? I mean is the power supply mounted horizontally across the top, or is it mounted vertically from the top down one side? You don't want anything blocking the cpu fan.-

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No no. My mistake. Chipset was the same
by Scott Swinyard / December 18, 2004 6:24 AM PST
In reply to: Well I'm no expert...

Do you live in a furnace?

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Quite simple. you have no REAL
by Ray Harinec / December 18, 2004 7:55 AM PST
In reply to: POWER!

problem. The 2.8 simply consumes more power than the prior CPU. Thus it runs hotter with a given HSF. Stop wastingt time worrying. Get up to 155 F and then worry a little. LOL

If the system performs flakily, an inadequate wattage power supply could be one of the causes. If no problems then keep the 300 watter. Any problems go to a 450 with that CPU. The 300 watter may weaken with time and start to have problems.

The system will not consume one iota more power than it needs, no matter how high the wattage of the powewr supply. Of course the power supply itself consumes power. They run about 65% efficiency thus an output of 300 watts will draw 300 divided by 0.65 input power = 461 watts. That 161 watts/heat will not get into the system if the Power supply fans are properly exhausting the heat from the supply.

Watts = heat because 100% of the consumed electrical power is converted to heat [everywhere in the world].

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(NT) (NT) 155 huh? Ok. Thanks Ray.
by Scott Swinyard / December 18, 2004 1:14 PM PST
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You never mentioned whether you took the advice.
by chuckieu / December 19, 2004 4:05 AM PST

Did you check with Intel about temps you SHOULD be running at? They should have CPU and case temperature optimums on their website. As to your question, first of all, that 300W power supply is probably only putting out a consistent 200-250W(unless it is something like an
Antec). The reason the P/S matters is that the more equipment you put in there, the more it has to strain, which raises the temperature. Good luck. chuck

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Everything
by UnWritten7 / December 19, 2004 5:35 AM PST

I have tried everything that has been posted but replacing the PSU. I havent had the chance to get another one yet since the computer store here is sold out of just about anything above 300w.I will try that next. I have noticed one thing since I disabled HT the temp has gone down some. Also when Im playing a game I notice the CPU usage goes to 100% and stays there until I stop playing. Is this suppost to happen?

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What is the problem that you
by Ray Harinec / December 19, 2004 8:45 AM PST
In reply to: Everything

are trying to fix??? The CPU temp is perfectly acceptable.

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Yes
by chuckieu / December 20, 2004 2:50 AM PST
In reply to: Everything

As I said, all of these tax the system(gaming is one of the worst). They are supposed to. That's why you do things like get a bigger PS, make sure you have good airflow, etc. I moved to round 80 wire cables to help( and it seemed to). I also have my side panel slid on where there is a 5-inch gap. Behind a post (unblocked)so the cat can't get nosy. What did Intel say the temps to shoot for were? chuck

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Correction. Sorry. The max temp for
by Ray Harinec / December 19, 2004 9:22 AM PST

the latest 2,8 P4 using .13 micron process is 75 C [167 F] and it draws 69.7 watts.

Got mixed up with the AMD T-Birds and XP's. The 64 bit AMD's are now showing 70 C upper limit. Much better thermal designs.

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From Intel PDF Spec Data Sheet
by billzhills / December 19, 2004 10:23 PM PST
In reply to: POWER!
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Billz
by chuckieu / December 20, 2004 2:58 AM PST

I scanned the PDF and noticed something. Unlike AMD, Intel only gives the minimum and maximum temps, not the
optimum(ideal). I could have missed it. chuck

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Intel spec sheet
by billzhills / December 20, 2004 7:45 AM PST
In reply to: Billz

I've been over that spec chart many times and still am unable to understand what Intel is saying.

Unless you factor in the different sizes in cases. Then I can understand Intel's temp ranges. AMDs ideal temp can only work in a lab under controlled conditions. A slim case will not cool as well as a mid size tower, a full size tower will cool ever better.

So I work off heat exchange, if I can keep the exhaust temp to 100 to 105f (at rear exhaust fan) under load (burn-in) then I my components have proper cooling.

If you want to do the Math
http://www.efunda.com/formulae/heat_transfer/convection_forced/overview_forced.cfm

Bill
.

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Take a look
by UnWritten7 / December 20, 2004 12:19 PM PST
In reply to: POWER!

Please anyone just take a look at my profile and see if you see anything else I could do. Also if you need a picture or diagram of my system I could email you a picture. Currently with the set up I have now the CPU starts between 118F and 124F. Using the internet and other small programs such as word the temp only goes upt to maybe 130F at the most. When I play games though it shoots up between 135F and 145F once it got to 155F. Is this normal for todays games? Also would it help to make a spot for another case fan on the side of my case shooting air towards the MB and CPU? Or would it just cause a dead zone around the CPU?

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That side fan,
by Ray Harinec / December 20, 2004 11:37 PM PST
In reply to: Take a look

blowing in should help. It'll stir the air up which may also help the memory, which are other items along with video cards that create a lot of heat and need moving air. All the heat creators increase the internal ambient air temp, and thus the HSF can't transfer as much heat from the CPU because of the lower delta T.

I only use cases with a top exhaust fan and the side fan [plus the normal PS fan CPU HSF, and intake and exhaust fans]. The top exhaust is a big help. We all know that heat rises. LOL

When you started this thread you didn't seem to have a temp. problem, your reported temps have risen with each post. LOL

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CPU Temps
by billzhills / December 21, 2004 12:16 AM PST
In reply to: Take a look

I don't think their is an answer to the question of correct/normal CPU temp......

Intell does not give an optimun temp for its CPUs. Only a Temp range taken off the top of the CPU. AMD does state an optimun temp for their CPUs, but under what conditions?

See: http://en.wikipedia.org/wiki/Temperature
.........When two systems are at the same temperature, they are in thermal equilibrium and no heat transfer will occur. When a temperature difference does exist, heat will tend to move from the higher temperature system to the lower temperature system, until thermal equilibrium is established.........

This is what I look for in my systems....heat transfer. Measured at the rear exhaust fan. If my incoming air is 78f and my exhaust is 100f under load I have good heat transfer and my components are being cooled.

Hope this helps

Bill
.

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Bill, If that exhaust is being measured at the
by Ray Harinec / December 21, 2004 3:04 AM PST
In reply to: CPU Temps

output of the power supply, the data may consist of a high percentage of heat from the supply that never even got into the system.

Your criteria for heat transfer really violates AMD and Intel statements drastically. They both recommend a maximum delta T, room ambient to interior ambient [about an inch above of the HSF hub, of 7 C degrees [12.6 F degrees]. Your delta T is 22 F degrees. That's why I assume that much of the delta is from the power supply. Try a thermocouple/thermistor sensor in the vicinity of the HSF hub and see what's up. The real heat transfer of issue is from the CPU core to the surface of its Heat sink.

Now that most CPU's have heat spreaders they don't specifiy the CPU core temperature any more. They spec the case [of the CPU] temp which is lower than the core temp. This is great because it gives something to work with and the heat transfer from the core to the heat spreader is excellent due to the manufacturing process, rather than a human applying [or failing to] thermal paste properly. Plus the spreader gives far more surface area to work with.

I really think that you have misapplied heat transfer theory. The ideal would be if the exhaust air temp temp was as close as possible to the intake air. The interior air should not have been allowed to rise that high. Just MHO.

Hey Bill, use the zephyr from that big hill.

Please take this as a technical discussion and not an argument.

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Bill, a little more.
by Ray Harinec / December 21, 2004 3:32 AM PST
In reply to: CPU Temps

Consder two computers, each dissipating 400 watts into the case.

One has a tornado blowing through it and the outlet temp is only 2 C dgrees above the inlet temp. The other has a few simple fans and the exhaust temp is 20 C degrees above the inlet temp.

The first case is a far more efficient thermal system. It's thermal coefficient is 0.005 degrees C per watt, the second 0.05 degrees C per watt.

If we talk only the CPU/HSF. A good number shown by Intel would be .15 d C per watt case[spreader] to heatsink base and .35 d per w heatsink base to its surface "touching" its ambient air. Thus total 0.5 d C per watt. One new 64 bit dissipates 100 watts, thus the delta T from its base to ambient air [@ .5] would be 50 C degrees [90 F degrees] Work it backwards from your 100 F ambient the CPU would be 190 F, which makes me certain that your interior near the CPU is not anywhere near 100F.

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Ok ... see what you are saying
by billzhills / December 21, 2004 6:18 AM PST
In reply to: Bill, a little more.

thats why I am hear to learn or get my facts correct.

The air temps I am using are from the exhaust fan not the power supply. And I leaned on this theory of mine from a system with the covers on. This system had a heat trace about 4" wide on the removable side cover and warm across the top. The heat trace ran from the APG card upwards to the CPU and rear fan. Changed the front fan to a faster one with a small tunnel and the heat trace changed to the exhaust fan area. (make any sense?)

This lowered the overall exhaust temp by 20f and the case, all sides, felt the same. Except for a small area around the rear fan and the top near the P/S.

On heat transfer, read that as a hotter object gave off its heat to a cooler one. Which would mean that the incoming air would absorb heat as it passes thur the case. Refelecting that heat transfer by a higher exhaust temp. Understand what you are saying tho about the incoming and exhaust temp being near the same.

So I guess my next step is to find some thermo devices
and see whats really going on.

Thanks for the input....

Bill
.

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The Radio Shack indoor / outdoor
by Ray Harinec / December 21, 2004 7:38 AM PST

digital thermometers are great for that. The outdoor sensor is on a long thin "cable". Easy to snake it through the case cover to get true airflow and temp readings.

What you observed makes sense, and what you did obviouly worked well, but the 100F out of the case still seems a little high if not from the power supply. And heat rises, which is why I use cases with a top exhaust.

The case that I use with top and side fans is cheap, and most will call it flimsy, but I do not use my computer as a football so they work fine.

I also use a full server type with top and side fans and many other fans, but that one is fairly expensive, and an overkill for the systems that I put in them.

With 100 watt CPU, hot memory and hot video, gotta move a lot of air through a system.

The thermal path through the new BTX cases is interesting. The BTX is taking a long time to catch on because it is such a major change and guys such as we manage to cool their ATX's with relative ease. Basically the fan on the CPU heatsink is perpendicular to the mobo and blows air from the rear of the case towards the front where it exhausts. Maximum PC magazine didn't like it, but ran tests which seemed to confirm that it is more efficient cooling.

I'll wait, like you, I have no real problem cooling systems.

The main problem with the front intake fan [on most cases] is that the path that it draws its air from is from the bottom [floor?] through the slight airspace between the metal case and the plastic face. Very restricted [resistive] path which probably doesn't let the fan perform at full efficiency and, of course, if the tower sits on the floor, it gets clogged pretty fast. Of course, I use them also because they are one of the only games in town.

I am not saying that what you are doing is wrong, just that you misapplied the theory of heat tranfer to measure effectiveness.

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Radio Shack indoor / outdoor
by billzhills / December 21, 2004 9:42 PM PST

Morning Ray,

Han't thought of Radio Shack, great idea.....

The BTX case is being offered by Gateway this year altho along with the PCI express I'm going to give it a year before using. By then the techonolgy will have matured.

On the front and rear exhauts fans I cut the metal out. The front cover still restricts the air flow but a little is gained.

Haven't looked at your profile but in several post or a post you have mentioned your training. Well beyond mine...so if I am going down the wrong path Please step in and show me the correct way. Again Thanks....

Bill
.

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Will be checking with you
by Ray Harinec / December 21, 2004 11:48 PM PST

for help on networking and a webserver, and possibly a DNS server. Reading a lot of books, but guys, such as you are the ones that really teach me.

When I ask about that it'll be in the Web forum. I posted a question there a few weeks ago and raa gave me a very useful link to two tutorials that he had written. Really good info to get me started.

Some really helpful people in these forums.

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If these are CPU temps...........
by chuckieu / December 21, 2004 4:07 AM PST
In reply to: Take a look

what are you complaining about? This is cool for normal use, let alone maximum stress. Centigrade temps for a computer make more sense to me, but if I converted right,
these are good. Why are you beating this to death? chuck

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