cancel
Showing results for 
Search instead for 
Did you mean: 

PC Cooling

N/A

PC Cooling

Got a lil problem guys. Few months back i had to have my still in warrenty motherboard replaced and since it was replaced the cpu worked at a high temp. Sent it back and they tested it and said it was fine. (Novatech Suck) Anyways i got a new AMD approved heatsink and fan few weeks ago and it cools the CPU a lot better than the old fan and sink. However the temp is still hot for my liking. The average idle temp is 55C and with a 100% load it can reach 62C. Recently with the warm weekend we had my room was a bit warmer than normal and the temp at 100% load reached 65-67C. So on the warm weekend i removed the side covers and after a while i was getting good temps of 50C idle and 100% load temp of 55C. So i guess its a exhaust problem. I got a 450W dual fan psu blowing out hot air aswell as a case fan under it blowing out and a case fan at the front bottom sucking in cool air. These case fans are the stock fans that came with the case. At this moment in time the temp in my room is 23C and at a full load the cpu is running at 62C without case sides on. But with them on and 100% load it was close to 70C. Ive been on a few websites and forums to see what are good safe temps but i got a different story from each one so i dont know what to think.

Sorry to babble on about it but basicly i would like to know if anyone could recommend a good couple of casefans that will remove the heat out better and also some that can increase the cool air intake. Price is not a problem.

CPU is AMD Athlon 2000+XP
Case is ATX

Thanks

Nath.
18 REPLIES
N/A

PC Cooling

Firstly, the temperature sensors on motherboards are notoriously inaccurate, by at least +/- 10%, so your new MB may simply be reading high. I use a separate sensor (from my old overclocking days) which indicates the temp far more accurately.
Secondly, any extra fan in the case will improve air flow by a large factor. Most MB's have connectors for extra chassis fans.
A suitable fan is one such as
http://www.scan.co.uk/Products/ProductInfo.asp?WebProductID=2565

or if you want to go to town on your CPU cooling
http://www.scan.co.uk/Products/ProductInfo.asp?WebProductID=66796
Community Veteran
Posts: 14,469
Registered: 30-07-2007

PC Cooling

What thermal paste are you using between heatsing and CPU? Get hold of some arctic silver 3 or 5 which can often reduce your temps by 5C or more.

Also how much thermal compound did you use. It needs to be a very thin layer for maximum heat transfer. Too much and it can act as a heat insulator thus reducing the effect of the heatsink. I apply it as follows:
- Clean both CPU and heatsink with metholated spirit making sure you remove all traces of existing paste/pad
- Put a very small drop of thermal paste in the middle of the CPU.
- Using a plastic food bag, place the bag over your finger and gently rub the paste onto the CPU surface so it there is a thin layer covering all the surface and as thin as you can get it.
- Fit the heatsink.

If you are using a thermal pad with your heatsink then I suggest you remove it and use the thermal paste I mentioned above.

The temps you are getting are a little too high for my liking. You should be running no more than 50->55C at full load with that CPU.

Running the PC with the cover off for extended periods is not recomended as hot-spots on the motherboard and PCI cards can occur which can cause damage over time.

Make sure the case has good airflow all around it. Even lifting it off the floor sightly can help. Don't put it in an enclosed space like a computer desk or up against a wall (on the side or back of the PC).

You also have less airflow going in than out which means there will be less internal air pressure so air will stagnate and not go through the case. You need to increase the incoming airflow by fitting more fans but if your case does not allow this there is not a lot you can do really. Also sometimes the airlow inwards at the from is restricted by the front cover, sometimes adding additional holes at the front can improve the airflow in.

Keeping the internal cabling tidy and try to make sure it does not block the airflow around the CPU.

Another option is to get a really good heatsinnk/fan + thermal paste. I use the coolermaster aero7+ which is one of the better ones. There are several models in the aero range now so try checking them out. They produce a much better heat transfer and cooling effect by using all copper heatsink & fans and a very powerful (and sometimes noisy) fan.

As you may already have all the fans you can fit in it, you may ultimately have a case that is not well designed and cannot produce the necessary airflow to keep the CPU cool enough. You may need to look at investing in a better case which allows multiple fans to be fitted at the front and back.
N/A

PC Cooling

The maximum operating temperatures for AMD Athlon XP processors can be seen here.......

http://www.amd.com/us-en/assets/content_type/DownloadableAssets/FAQ_Rev05_ENG.pdf

.......and i stress these are maximum not recommended!
Community Veteran
Posts: 4,729
Registered: 04-04-2007

PC Cooling

I had similar hot running problems with my system, which where to poor case design. Inadequate air inlets leading to negative internal pressure.

My solution was to fit a fan into the side panel, blowing cool external air directly onto the CPU heatsink.

Ok it was not the easiest of jobs, requiring a jigsaw to cut a 80mm Diameter hole, but with a chrome wire fan guard and a illuminated fan it looks OK, and more importantly had a massive impact on the internal temperature within the case. Internal air temperate and CPU temperature where both reduced by well over 10C.

Chilly
N/A

PC Cooling

Thanks very much for the info guys Smiley

Im not using any thermal paste but a pad instead. It came with the heatsink. I only didnt use paste because the bloke at Maplins said pads were better for a long term solution where as paste was mainly for use if you was going to remove the heatsink often. And also because ive never used paste before. Ive never had to change the heatsink and fan over. But ill see about getting some paste and giving it a go now that i know how to do it properly. Thanks Peter Smiley

Im currently looking for something to raise the tower off the floor a bit. Theres not much room in my room at the moment so moving it somewhere else isnt possible at the moment. My fiancee has moved in with me and so all her crap has come in the room lol. But i guess i could try and increase the airflow around the outside of the case as its not fully in a corner but its in one.

The cpu fan and heatsink i got is Akasa AK785cu XP3000. I just found the box out.

I will see about getting better case fans too but also would you recommend those blowers that fit in the pci slots?
N/A

PC Cooling

Don't remove the heatsink from the CPU just to remove the heatsink pad and replace it with paste.
If you are sure you put the heatsink pad on correctly, there will be little advantage in doing this. I assume it was a new pad, they are not reusable.
N/A

PC Cooling

Thanks. I didnt read through what i said ealier lol. Was ment to say that i would consider it. Was half asleep Shockedops:

Anyways yes it was a new pad it came with the heatsink. To be honest id rather never take the heatsink off again because the board that was replaced with this one died after i took the heatsink off after novatech told me to replace the paste with a pad. After that the board never worked again. So when i changed the fan and sink i was worried it would die again. Thats the last time i buy all my parts from them. Evil
Community Veteran
Posts: 14,469
Registered: 30-07-2007

PC Cooling

Arctic silver 3 or 5 is way better than any pads you will get and worth the effort of using it as it does give much better heat transfer (when used properly) which is your main problem.

The PCI blower fans are designed to suck air out but your problem is your not getting enough air in so it may not produce any noticable different to your internal temps. Putting a hole in the case side and fitting a fan probably would make a difference, making sure it blows air in not sucks it out.

Also remember to never remove the heatsink while the system is running, it takes approx 0.5 seconds to cook (i.e. damage) the AMD processor without a heatsink and there is no thermal protection like a P4 processor. Also be careful when fitting the heatsink back and don't put too much pressure when trying to clip it on.
N/A

PC Cooling

No doubt some heat transfer pastes are better than others and may be better than pads. The difference though will only be a few degrees.
However, one reason AMD recommend pads is that they offer some protection to the chip when fitting the heatsink. With paste you are more likely to damage the die when refitting the heatsink. The heatsink must also be of the right size and heat dissipation rate for the CPU.
http://www.scan.co.uk/Products/ProductInfo.asp?WebProductID=69430
Some Heatsink/fan combinations are not really up to the job of cooling a AMD 3000+

Getting good airflow through the case is also very important.
Community Veteran
Posts: 14,469
Registered: 30-07-2007

PC Cooling

The processor being used is an XP2000+ (see fisrt post), the heatsink recently bought is rated for an XP3000+.

You can also do much better than that heatsink but you do have to pay nearer £30 - see http://www.overclockers.co.uk/acatalog/Online_Catalogue_Coolermaster_122.html I use the last one listed the Aero 7+, running XP2800+ barton (2.08GHz) O/C to 2.4GHz @ 50C die temp, with CPU 100% loaded with distributed computing (grid) software.
N/A

PC Cooling

My mistake on CPU speed, I thought I had read 3gig somewhere.

The comment made earlier needs acting on,
Quote
You also have less airflow going in than out which means there will be less internal air pressure so air will stagnate and not go through the case.

Simply turn the one case fan around that is blowing out, so it sucks in. The you will have two fans blowing out and two sucking in.
Community Veteran
Posts: 14,469
Registered: 30-07-2007

PC Cooling

The only fan that can be reversed is the one at the back below the PSU and this will just suck in the hot air blown out by the PSU fan (especially if it is blown out against a wall) which in turn will be exhausted by the PSU fans so that will probably have a negative effect in the internal temps - It causes a hot spot potentially around the CPU thus reducing the effectiveness of the CPU heatsink & fan. That read fan below the PSU is probably near the CPU heatsink as well so blowing air in around the heatsink will actually reduce the effectiveness of it.

The ideal solution is airflow lower front to top back over the CPU area - 2 or 3 fans at the bottom front sucking in air (which should be cooler), or 1 or 2 fans bottom font and 1 on the side case above the CPU blowing in air which will then flow over the CPU area and be exhausted by the PSU and additional fans at the rear and top this also maximises the cooling of the PSU. However, very few standard cases allow you to do that so you need a very good heatsink - ideally copper, plus a powerful fan to blow as much air over the heatsink and thus cool the processor.
N/A

PC Cooling

Thanks for the info guys.

I have been thinking lately about those Jet units. My recently bought fan and sink was only £19.

I will get a better case fan for the bottom front that will suck the air in. Would be nice to have 2 there but the iternal speaker is next to the current fan. But i will get a better one and then make a hole on the side and fit another. Do you think it be wise also to replace the rear fan with a better one to suck out? Also could someone please explian CFM when talking about air flow? Ive looked at a few casefans on the net and i dunno whats better. A Higher rpm or a higher CFM?

Thanks again all.
Community Veteran
Posts: 4,729
Registered: 04-04-2007

PC Cooling

CFM is Cubic Feet per Minute, this is more important than RPM when selecting a fan.
In fact lower RPM with the same CFM is best as the noise from the fan should be a lower frequency, and less intrusive.

Chilly