processor not running at full speed

[RabbieBurns]

got a trolley of 10 exact same laptops, pretty old and slow things. Some are running slower than others, so looking at system properties (xp sp3) I see that some are running at 1.6Ghz (which is what they are) and some of them are running at 797Mhz. There is no option in the bios to set the speed. They all have 512mb ram, which as far as Im aware is what they were shipped with.. Any ideas why some might be running slower than the others?

[SYNACK]

Have you checked what windows power schemes are being used on the offending laptops, they could be set to max battery instead of minimal power management and stepping down the clock speed to 50% in an attempt to save power even if they are plugged in. Also check the CPU temps and the cooling paths inside the laptops as if they are getting to hot they could also be stepping their speed down automatically.

[RabbieBurns]

Interesting, I hadn't clocked that 797 was pretty exactly half of 1600.

 

Ive compared the power scheme settings of a full speed and half speed. Both are exactly the same, default portable/laptop scheme.

 

I will try changing them to mimimal power management and see if that makes a difference, cheers.

[FN-GM]

What processors are they?

 

Z

[srochford]

Is there a BIOS setting about SpeedStep or anything which looks like speed or power management - does look like they've decided to slow down to save power.

 

What happens if you do something CPU intensive (play a video, for example)? It could be that when they're idling they just slow down the clock but will wind it up again when needed.

[Michael]

It's all to do with conserving power, after all, will a CPU operating at 797MHz make any difference to word processing or browsing the internet? The additional speed automatically kicks in when CPU use increases (like watching a video).

[craiglay]

This is probably Speedstep as my laptop and pc sometimes shows this. Try running CPUZ on the affected machine and see what that says. It will give you a realtime indication of CPU speed.

 

Craig

[CyberNerd]

my linux laptop does this, at low load /proc/cpuinfo reports cpu 1200MHz. But when its under load doing something /proc/cpuinfo reports a 2200MHz processor.

 

If I do

 cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies 

it shows: 2200000 1200000

 

so basically it scales the cpu on demand

[RabbieBurns]

they are amd opteron 2800 I think, Ill double check in the morning.

 

I never knew aboout the variable speed thing. Will have a look tomorrow.

 

Cheers

[mrbios]

they are amd opteron 2800 I think, Ill double check in the morning.

 

I never knew aboout the variable speed thing. Will have a look tomorrow.

 

Cheers

 

Probably cool'n'quiet (an AMD thing since A64s were released) if it isnt a power saving setting in windows

[RabbieBurns]

My mistake, they are Sempron not Opteron. As I say they are pretty old. HP Compaq nx9105. Had the CPU up at 100% playing a couple of videos and doing a large network transfer but system properties still showed only 797.

 

msinfo32 shows:

 

x86 Family 15 Model 28 Stepping 0 Authentic AMD ~ 797 Mhz

 

The ones that were 1600 yesterday have booted to 797 today.. Strange.

 

There is nothing in the bios at all about Speedstep or such, I will try CPUZ today.

[RabbieBurns]

OK, well CPUZ showed it fluctuating between 798.0 and 1595.0 so I guess all is well.

 

Thanks for the info

[richard.thomas]

We had this on some of our Compaq laptops. As other people are saying it was because of power management. It'd scale down the CPU speed because it was on battery but it never turned it backup!!

We just changed the settings in the 'Power Options' and this sorted it

[tarquel]

I personally cant stand this feature, while of course it has its uses, is a very annoying feature as in many occasions, you get lag when doing stuff while the machine attempts to pick up the pace.

 

Maybe its not true of all machines, but all the ones I've seen in the past do this, including my Intel P35 based machine at home [which i soon turned that feature off and lag-free running as a result ].

 

Maybe i multi-task alot or have that much running with fluctuating usages that i cause it myself, but still.... you dont buy a Jag to drive at 5mph most of the time do u?

 

Just my 2p.

Nath