[CPU] Question about high CPU temps (AMD)

kumori

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Oct 12, 2009
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I'm currently running a custom build (about a year old) and it seems the CPU temps are higher than in the past. The build is as follows:

Antec 300 case
1 140mm top case fan (run on low speed)
1 120mm back case fan (run on low speed)
AMD Phenom II 965 BE 3.4ghz (no OC, stock cooler)
12 GB RAM (using all RAM slots)
Gigabyte MA790GPT-UD3H
Corsair CMPSU-650TX 650W PSU
SAPPHIRE 100283L Radeon HD 5770
Samsung F3 1TB HD
WD 320GB HD
Windows 7 64-bit

I bench tested it a year ago before the video card addition (so integrated graphics) and got

NO VIDEO CARD

Idle: 31 C
Load (Prime 95 for over 1 hour): 67 C

I just recently decided to test for temperatures again and used Prime95 with CoreTemp to monitor, and the temperatures were getting fairly high.

(WITH HD 5770)

Idle: 37-38 C
Load (Prime 95 after 2 minutes): 77 C

Video card Idle: 58 C

I actually stopped the Prime 95 test about a few minutes since the CPU temperature kept going up and I didn't want to hit the CPU Tj Max (78 C according to CoreTemp).

Should I be looking to add more case fans to the front and side? Should I probably consider a new after-market CPU cooler like (this)?

I'm concerned about the stability of my machine once I get to putting under more stress playing games and such. I'm looking to keep my computer as quiet as possible (one reason I run the fans at low speed), but still maintain good cooling so stability isn't a problem.

Thanks for any suggestions.
 

HankB99

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Have you checked the inlet filter on the case? I think the Antec 300 has a filter where the front fans would mount. Does it run any cooler if you crank the fans up or open the side of the case and direct a small fan at that? Those are things I would check in addition to the suggestions already posted.
 

Uther39

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And by the way no game will ever stress your CPU like prime95 does so it would never get that hot during gaming, also when you install the 2 front 120mm fans plug them into you motherboards 3 pin sockets so that your motherboard can control there speed according to your system temps to get you the quietest and coolest solution.

I use these fans http://www.overclockers.co.uk/showproduct.php?prodid=FG-045-AK&groupid=701&catid=57&subcat=4, and by the way i also have an antec300
 

hangfirew8

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I have a similar setup- unlocked 4 core 550BE at 3.4GHz, in an Antec 300. However I only have 4GB but I run three Scythe 1200RPM 120mm fans, a 140 and a Mugen 2. I don't recall my prime95 temps offhand but they were very much under control.

You might have a recirculation of hot air between the video card and the CPU fan, or the CPU cooler may not be sitting flat and flush with the CPU.

Do you have an flat IDE cable for an optical drive? Are all the power wires and data cables tied down and out of the air path?

The Xigmatek cooler is OK but if you are into quiet, get a cooler well rated for such, like the Megahelams, Mugen 2, Silver Arrow, T.R.U.E., etc.

Also the stock Antec fans are not the quietest, even on Low. Noctua's or Scythe's under 1500RPM will do as good or job or better with less noise. If you get additional ones for the front you may end up with better airflow and no additional noise.


 
Is your 965 the 140watt or the 125watt version?

Dunno how but you must have installed the heatsink wrong.62c is the max temp for the 965BE.So you've exceeded the max temp by a lot.Not sure how you got to 77c,surprised it didn't shut down or anything.You've definitly overheated your CPU.

Try reinstalling the heatsink and put a a new layer of thermal paste in.Those temps are rediculosy high.

And yes that heatsink you picked out should work wonders compared to the stock heatsink,i reccomend getting it asap.

Do you have any Overclocking software installed?AMD Overdrive maybe?

EDIT:Nvm about which wattage 965 you have they both have a max temp of 62c.
 

kumori

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That was one thing I was thinking of doing. I originally just used the stock cooling pad and haven't touched it since. I thought that it would be good enough since I don't plan on overclocking. I have so Arctic Silver Ceramique, so I could apply that.

Go into the bios and drop the cpu voltage down to 1.3v. I have a feeling it's set at 1.45v in the stock bios

I'll check the BIOS, but I don't really want to drop the voltage down, the voltage already seems to clock down when idle.



I think it did run cooler when I cranked the fans up to medium in the past (lowered by 2 to 4 degrees), but I didn't like the noise, so I dropped it down to low again.



My motherboard appears to have 1 4-pin system fan connector, 1 3-pin system fan 2 connector, 1 3-pin Northbridge fan connector, and 1 3-pin power fan connector. I am thinking about getting some front fans though.



I used the stock fan because I didn't plan on overclocking and didn't want to go to the trouble of installing an after market heatsink.



62c seems kind of low, since I was over that on Prime95 load even before installing the video card. I'm very sure I installed the stock fan right. There is no overclocking software installed.

my first move as well..

^
second move..

Thanks for all the suggestions! I think I may try reapplying the CPU paste, but I might just get an after market cooler first instead and then applying the paste. I probably will also add some front fans to create better airflow.

I'll certainly try running the fans faster and opening the case to see if that helps first to figure out if its a cpu fan or airflow issue.

The computer sits under a table, so the fans don't have to be dead quiet, but I'm pretty satisfied with the Antec stock fans at low (just not at medium). I'm trying to balance between quiet, quality fans, and price (since the most quiet fans seem to be rather more expensive). Also for a new cpu fan, the CPU is very close the RAM slots and I use all the RAM slots, so I want to ensure that a new after market cooler doesn't obstruct a RAM slot. Looking at a 92mm fan, but I also took at a look at the Corsair H50 although I'm not sure I want to deal with that side fan. I'm likely to consider adding a side fan anyways though for more air flow.
 

loneninja

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Common cause of increased temperatures is dust build up reducing airflow. If it is dusty, get some compressed air and blow it clean.

Another thing worth noting is Gigabyte boards tend to overvolt AM3 processors. Check your voltage, it should be in the 1.35-1.4V range, if it's any higher drop it. You could probably run at 1.3V or lower and still be stable.
 

kumori

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Running a session of NBA 2k11 (1440x900, settings all high, no AA, Vsync on) I get CPU temps in the 66 to 69 C range according to Core Temp logs.

Checking the BIOS, the voltage tweak tool says that the CPU's normal vcore is 1.375v (so decreasing the voltage by .025 drops it to 1.35v), although when checking the bios PC Health tool, the CPU voltage is 1.44v. I decided not to undervolt because I'm not sure exactly what this means.

At this point rather than re-applying thermal paste, I think I'll just get a new CPU heatsink and apply the thermal paste there. Any suggestions for a small, yet effective CPU cooler for a Phenom II? I was thinking about the Corsair H50, but I'm not sure I want to deal with the extra cables.
 
The Voltage Tweak won't display the voltage in real time the PC Health Satus does.So go with the PC Health Satus as the real voltage.I don't know why your voltage is at 1.44.Thats no where near stock.Try lowering the voltage by .25 until the pc health staus reads it's at 1.4 or 1.375.You should see a huge drop in temps.
 

kumori

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I have the 125w version of the 965, so the default is actually 1.375v.

I dropped the voltage by .025 in the BIOS so the the voltage is now 1.35 instead of 1.375. For some reason now the PC Health tool reports the voltage as 1.328v. CPU-Z also reports this (when the processor is on load). The temperatures are a bit better.

Idle 33-34 C
Prime 95 (after 25 minutes): 68 C

The temperature didn't spike up really quickly on Prime95 like before, but instead it slowly, but steadily got up to 68 C over that 25 minutes before I stopped it. I also boosted the chassis fans to medium speed, even though I don't like the noise. This should tide me over as I get some new fans.

Odd that a .025 drop in voltage would drop the CPU voltage from 1.44v to 1.328v.
 
The defualt voltage for the 965 is 1.4.I would try running it at 1.375.It will always display a .01 or .10 difference from what you set it as.That is just the way electricty works and how the mobo and supply regualte it.It's an imperfection.

Are you sure your reporting those temps correcntly?68c?Those temps are waaaay off.I would return that processor if it's under warranty and get a new one.The max temp for the 965 is 62c.So for you to be in the 70's and 60's is just bad.

If you didn't touch the voltage and it just auto put it up to 1.44 you should talk to either your mobo or chip manufactuer and ask for a refund because they ruiend your prosscesor.
 

kumori

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Yeah I know the Prime95 temp is still high, I don't plan on stopping the tweaking here. I'll try to set the voltage to 1.3 and test temps again. I came across a forum post that said something to this effect:

"When you undervolt you also have to play around with the NB voltage and try to find stability."

Of course they were talking about undervolting a Phenom II to 1.18v or 1.07v, but is that something I should be concerned about?