A lot of people are having issues with Phenoms overheating when used with the stock AMD heatsink and fan (HSF). A very common problem is that the CPU voltage has been set incorrectly by your motherboard Bios. This article is a step-by-step guide to adjusting core voltage for the Phenom processor to prevent overheating with the stock HSF.
Step 1: Get the proper measuring tools.
There are three programs that you will need:
Speedfan: www.almico.com/speedfan.php
Core Temp: www.alcpu.com/CoreTemp/
Your graphics card's manufacturer's utility to read the graphics card processor's (GPU's) temperature. For Nvidia cards, this is the Nvidia System Monitor utility that comes separately or packaged with Ntune: www.nvidia.com/object/system_monitor.html.
Step 2: Install the 3 programs and figure out what the heck is what.
There is one main temperature that you need to identify: the Core temperature (also known as TCaseMax.) In AMD chips, there is a special diode inside the chip that measures the cpu's temperature with perfect accuracy. However, motherboards come with another thermostat that sits under the chip (also called TjunctionMax). This temperature does not tell you what the chip's temperature really is, and is often confused with Core Temperature. To add to this confusion, your motherboard may have a host of other thermostats that are reading temperatures from all over the place. You may need to get other utilities that read other thermostats just to eliminate them.
(For more information about reading CPU temps, this article is more detailed but technical: www.overclockers.com/articles1378/index02.asp).
On my computer (AMD Phenom X4 9750, Asus M3A motherboard), Speedfan will give a temperature summary like this:
Temp1: 54C
Temp2: 38C
Temp3: 25C
Core: 47C
Core: 54C
Ambient: 0C
After using the other 2 programs (along with utilities that came with my Asus board,) I was able to interpret this chart as:
Temp1: Tjunction
Temp2: Motherboard
Temp3: Ambient
Core: CPU
Core: GPU
Ambient: N/A (although it would be extremely cool if I could make my computer an ice machine.)
Step 3: Figure out if your computer does have a heating problem or not
While this may sound counterintuitive, idle temperature doesn't matter one bit. What you are worried about is maximum operating temperature under a sizeable load. At this point, run the program that is causing your computer to overheat which brought you to this article in the first place. As a general rule, silicon begins to become unstable at 60C, and could become damaged at 70C or higher. Therefore, most Phenom chips are set for emergency shutoff at 61C. If your computer idles at 30C, it won't matter if it shoots up to 75C in 30 seconds. Conversely, if your computer idles at 50C, it won't matter if it maxes out at 55C after 1 hour at 100% load.
If you don't have any suitable program, you can download SisSoftware's Sandra benchmarking tool at: www.sisoftware.net.
Another rule of thumb is that if your voltage is set at 1.25v or higher without overclocking, there's a good chance the voltage is set incorrectly. Out of the box, the stock factory setting for my 9750 on the Asus M3A was 1.33v.
Step 4: Adjust your CPU's voltage
If your computer overheats too quickly, and doesn't level out, it is very likely that the core voltage is set too high. Check Vcore1 voltage in Speedfan. It should be in the bottom of the opening screen. If this number is greater than 1.20v or 1.30v, we need to adjust this to be lower. First, check your CPU's voltage at: products.amd.com/en-us/DesktopCPUFilter.aspx. If you aren't sure which processor you have, download CpuInfo at: www.amd.com/us-en/Processors/TechnicalResources/0,,30_182_871_15259,00.html. CpuInfo is also useful to check if you've lost performance by changing the voltage.
Then, get into your computer's Bios. Hopefully, at this point, you've flashed your Bios with the most updated version of the software. If not, you can find motherboard-specific instructions online. Get into your computer's Bios. As a precaution, we'll turn off Cool n' Quiet at this point. (Cool n' Quiet is special cpu-specific instructions that allow functionality [and thus power consumption] to decrease during idle times.) Find "Cool n' Quiet" in your Bios, and set it to "off" or "disabled." Also, set ACPI 2.0 support to "disabled." This will prevent Cool n' Quiet from messing with our readings.
Then, find the voltage settings. On my motherboard, it's under "Advanced" -> "JumperFree Configuration." Set "Processor Voltage" to "Manual," or just keep playing around with "Auto" and "Manual" settings until you are able to adjust processor voltage.
If you found your recommended processor voltages at amd.com above, you should have an idea of the minimum voltage your CPU requires. However, experimentation has found that the recommendations at amd.com are inaccurate. Some chips require more, other chips require less. This won't matter for us. We can change the voltage without harming the computer even if we set it too low. Also, this technique is not meant for overclocked chips. Keep the clock speeds at default or factory settings.
Now, you have to do these steps repeatedly until you figure out the minimum voltage for your processor:
1. Adjust the voltage.
2. Save and exit Bios.
3. See if Windows will boot.
4. If Windows does not boot, repeat with a higher voltage.
On my computer, a voltage setting of 1.115v will result in an actual core voltage of 1.14v. It may take some experimentation to figure out the difference between the Bios setting and the actual voltage.
Also, note that at amd.com, my chip has 2 versions, a 95W and a 125W. However, my setting of 1.14v fits neither one's minimum recommended voltage. Therefore, I think the recommended voltage is merely a ballpark figure, and varies widely because of binning procedures. Your chip is probably the same.
Step 5: Computer's stable, now what?
Now that you've set your computer to the minimum voltage, let's check to make sure that you are receiving the performance you are supposed to receive.
First, check to make sure that all other voltages are the same in Speedfan. If the non-Vcore1 voltages are different, it's very likely you have Cool n' Quiet activated. Deactivate it for now by going to Display Properties -> Screen Saver -> Power and setting the Power Scheme to "Home/Office Desk."
On my chip, the voltages look like this:
Vcore1: 1.14v
Vcore2: 3.30v (Note: some programs will label this voltage as +3.30v. It doesn't matter. One of your voltage readings should be 3.30v.)
+3.3v: 0.00v (this number must have been labled Vcore2 above.)
+5v: 5.00v
+12v: 11.71v
Here are the same numbers with Cool n' Quiet activated:
Vcore1: 1.06v
Vcore2/+3.30v: 3.30v
+5v: 4.97v
+12v: 11.78v
Then, check CpuInfo and make sure all cores are working at the right mhz. They should all be the same. On my computer, all cores are working at 2400 mhz. However, with Cool n' Quiet activated, three of the cores will switch to 50% speed.
Then, start up Sandra, and run one of the CPU processor benchmarks. You can leave Speedfan open at this time, and it may be a good idea to also open Speedfan's temperature charts to monitor your Core and Tjunction temps during the test.
During the test, the behavior you should see is a slow, steady temperature rise that peaks at around 55-56C core temperature. Tjunction temperature may rise past 60C, but this will not harm the chip. Also, you may notice that idle temperature is the same or even higher. This is normal too.
Here are the results for my chip after voltage adjustment:
Temp.......Safe Range*........Max*........Full Load, Sandra.....Idle
Tjunct........<75C.............115C.............63C.......................53C
Core..........<60C.............61-65C..........53C.......................46C
*from amd.com.
And that's it!
If your processor is still overheating after these steps, it is possible that there is something else wrong with the computer, HSF, ventilation, or thermostats. However, this should fix the issue of a computer that overheats too quickly under minimal loads with a properly installed HSF.
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9750 X4 // 8600 GT // PC-6400 DDR2 800 mhz 1gig X 2 // WD 500 GB SATA HD // 580w PSU // Core Contact Freezer w/ IC Diamond 7 // DVD-RW // Win XP 32 bit // CPU-Z Validation #420180
Edited: 08/10/2008
at 04:46 PM
by Superhal
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08/04/2008 09:33 PM
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