T2500 (2.00GHz) running at 1.99 GHz?

I have a E1505 Core Duo T2500 (2.0GHz) laptop. I've noticed something interesting.

Occasionally when I check My Computer -> System Properties -> Computer, it lists the processor as "T2500 @2.00GHz", ok it looks fine there...but right below that, it also lists the actual processor clock speed (I believe) and the amount of memory.

It seems the actual processor speed is not consistent everytime I boot up my computer to desktop. Say if I restart my computer 10 times and go to System Properties everytime to check the computer info, sometimes it lists the processor speed running at 2.00GHz, while other times it shows the processor running at slower speed 1.99GHz (see below), it's about 50-50 I guess. Just curious, is this normal?

Genuine Intel (R) CPU
T2500 @ 2.00GHz
1.99GHz, 512 MB of RAM

For those of you who have a laptop with a T2500 processor (2.0GHz), does this happen to you too?

 

mine is often running at around 1ghz (998mhz) the core du just hangs out at a speed just above what you require. so obviously you are using it at its full potential and then sometimes you arent.

 

I don't remember ever seeing the processor speed of my old computers (Celeron, Pentium 4) fluctuate like this. They also always ran at the specified CPU speed I think.

Is this just the way the new Intel Core Duo processors behave? I just hope it's not my system being unstable.

Thanks.

 

This is expected behavior for duo core processors. You can read all about the processor at Intel's website.

 

Its quite normal. It happens in any processor. A clock speed is basically derived from a transistors turning on/off, so these small fluctuations are quite normal.

The cpu staying at 1GHz is due to Speedstep which helps in power consumption and is a normal feature of mobile processors a well.

 

I clicked Dell Quickset -> System Information, it shows the processor as:

"x86 Family 6 Model 14 Stepping 8 Genuine Intel 1995 MHz."

Is any other T2500 (2.00GHz) owner's CPU also identified as 1995MHz?

 

Your processor speed is going to be relivant to the voltage going into it, this is why you can Overclock or Underclock your processor speed by adjusting the voltage going into it. My own T2500 processor seems to be always constant though I also don't plug directly into the wall outlet at my house and instead go through a rather expensive APC battery back up surge supression system just because I've had to replace too many power supplies here because we seem to get some really dirty power in my area and your run of the mill surge protectors don't save me from the dirty power problems we get in my area.

Unless your also going through a simular high end power supply that your plugged into then it would make sense that the cheap power supply that converts your AC voltage to DC voltage to power your laptop would also fluxuate with the available line voltage feeding itand this would be dependant not only on the power usage at the time in your own house, but could be influenced by the power usage on your entire grid or nieghborhood. If you had a good quality digital voltage meter to check with you'd probably find when you were sensing lower speeds on your processor your probably also going to see lower voltages coming out of the wall outlet your plugged into.

I've seen the power at my own house range from as low as 108V AC to as high as 139V AC. If your living in the US then the power supply that came with your laptop has a step down type transformer in it that was designed to work at exactly 120V AC, the DC output voltage it produces from the bridge rectifier built into it is going to be directly proportional with the supplied voltage. So low voltage going in means lower voltage coming out which means a slower clock speed. Your talking a difference from 1995MHz to 2000 MHz which isn't very much, just having the electric clothes dryer in your house and the compressor on your refrigerator kicking on could cause enough of a voltage drop in your house to make this minimal of a difference.

With the differences your describing here I wouldn't lose any sleep over it, as a end user your not going to notice any dramatic slow downs or lock ups because of it, if you weren't looking for this problem you'd never even know it was happening and it's not going to cause any damage. Modern electronic devices for the most part are designed to allow for these minimal voltage fluctuations without doing any harm. Without doing the actual math on it I'd guess your looking at an extreme voltage drop at your wall outlet from 118V AC to the normal and probably steady 120V AC your getting at your house which is minimal and far from the damaging extremes I experience where I live.

Even if you believe your voltage is steady other factors can apply like the frequncy of your AC power. If you understand how your power supply works, that's the black plastic box you plug into, it basicly has a transformer in there which is nothing more than coils of wire. Voltage in corrolates with voltage out, but since we're talking AC power here then the frequency of that voltage applies as well. Yes it's a standard rule of thumb that in the US your going to be running AC power at 60Hz, but this can fluxuate as well depending on something as simple as the types of devices you have running on the same circuit in your house where you can also get feedback voltages up your nuetral line, add to that a bad ground circuit and things can get even screwier. Stuff like fluorescent lights and microwave ovens can play havoc on the frequency of the AC power your plugged into.

Even just the routing of your AC power cords can have an effect on things like your CAT5 cables and WiFi and once your aware of all this stuff you become rather anal about the routing of all your power cords and your power supply like I get.