Topic Title: Clock rate problem with A8-4500M APU
Topic Summary: Not able to hit maximum clock rate of 2.8 gHz
Created On: 07/15/2013 10:27 AM
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 07/15/2013 10:27 AM
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Joined: 07/15/2013

I am experiencing a problem with my AMD A8-4500M APU.  It is rated to be able to run at 2.8 gHz, but I have only seen this speed once or twice, very briefly.

The clock speed changes depending on the power setting in Windows that I am using.  On the max power setting, the highest I can get is approx 2.3gHz (100 x 23.0).

Note: computer is a laptop, model specified below.

I don't know how to get the APU to run at it's maximum capibilties.  Can anyone help with this?


Graphics Card
- AMD Radeon HD 7640G (integrated graphics)

AMD Catalyst Driver Version, and Driver History
- 13.4

Operating System
- Windows 7 Home Premium SP1

Issue Details
- My APU dynamically clocks based on the power setting I am using in Windows.  This can range anywhere from 0.8 gHz to 1.3gHz to 2.3 gHz at it's max.  The APU is supposed to be able to go up to 2.8 gHz but in no way have I been able to achieve this on my own.  I have seen it rise to 2.8 briefly only a few times - it is hard to say when this occurs, although I seem to remember it happening at the start of Windows once.

Motherboard or System Make & Model
Board: AMD Pumori Base Board Version
Bus Clock: 100 megahertz
BIOS: Insyde Corp. 1.10 05/10/2012

Power Supply

- 65W (19V 3.42A) Auto-sensing, 100-240V / 50-60Hz input

Display Device(s) and Connection(s) Used
- HD TruBrite® LED Backlit display, 14.0" widescreen

Applications and Games

- Any usage of computer within Windows

CPU Details
- AMD A8-4500M APU

Motherboard BIOS Version

System Memory Type & Amount
- 2 GB stick and 4 GB stick, DDR3 1600 mHz

Additional Hardware
- None

Additional Details
- Computer is a Toshiba Laptop:

 07/23/2013 03:13 PM
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Posts: 11
Joined: 07/23/2013

This is where you need to research a little more.  That higher rating is with Turbo Core enabled under certain conditions.  The Windows settings may be too generic to really help you here.

For turbo core to work it must be enabled (check your bios settings.)  Next the load needs to be only one or two threads / processes.  Basically the TDP (thermal design power) rating comes into play.  When running a light load, the CPU/APU can turn off unused cores.  When those cores are turned off, they stop creating heat.  Then the still running cores can be overclocked without exceeding the maximum wattage rating (TDP.)

The idea is that higher workloads finish faster with more cores at slower speeds.  Lighter workloads run best with fewer cores at much faster speeds.  Windows is not always great at process management, so you may not  always see the best combination being used.

I hope that helps clarify why you are not seeing your max speed rating in practice.  I don't believe that there is anything wrong with your rig, but the operating system may not be making the best use of it.


From a Tandy w/AMD 286/12mhz and 1MB ram to FX-8350 w/32GB ram.  I don't know everything by far, but I have probably forgot things you never knew.  Always happy to help, happy to be wrong, and happy to learn.

 07/23/2013 08:00 PM
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Heavy Wizardry

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Joined: 11/13/2009

...and as AMD article points out. There is a lot of good information in the FAQ section of the forum FAQ


Intel I7 960 @ 3.87ghz *Intel DX58SO *AMD R9 290 4gb *Corsair TX650M *2x4gb Corsair XMS3 *WD Black 1TB *Windows 7 Home Premium 64bit ***Asus N71Jq laptop *Intel I7 720QM Processor *Mobility Radeon HD5730 1gb *8gb Ram *Windows 7 64bit ** Toshiba P75-A7200 * Intel I7-4700MQ * Windows 8.1 64bit 

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