Dell Inspiron 5150 - Low CPU speed

Question

Hi, I've just got back my Inspiron at my office, coming back from Dell support for a motherboard problem. I've just installed a Gentoo, as it was set up before the motherboard change. The really ennoying problem is that when I boot, the CPU is detected correctly at boot: -> cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 15 model : 2 model name : Mobile Intel(R) Pentium(R) 4 CPU 3.06GHz stepping : 9 cpu MHz : 3059.921 cache size : 512 KB physical id : 0 siblings : 1 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 2 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe cid bogomips : 5996.54 The problem is that the CPU doesn't run at ~3GHz, 400-500MHz would be more realistic. I've tried a small soft (bogo) that gives me ~900 BogoMIPS. I know that BogoMIPS is not a really relevant measure, but here it shows the gap. For information, I'm running a homemade 2.6.8.1-SMP kernel, but it was the same with the generic 2.4.26 gentoo kernel. I've flashed the BIOS with the A36, in case of... I don't know what to do, so if anyone has an idea it would be greetly appreciated. Thank you, Kerso.

kerso · Answer

Just an update to my post.
I think I identified the problem:
- cpu throttling is set at state T6 at boot
- I can change it up up to T7 but not downgrading it lower than T6

Could it comes from ACPI kernel management, BIOS, hardware...

Any suggestion would be greatly appreciated.

Kerso.

msbridges · Answer

Why are you using a two processor kernel ? That could be why your laptop is running slower.

reefcrazed · Answer

If you are really worried about it turn off CPUSPEED in the list of things running at boot up, problem solved it will run at max all the time.

kerso · Answer

I'm using a SMP kernel because whitout SMP activated, I've got an interrupt conflict with my ide controller. I can solve this problem by deactivating ACPI at boot or activate SMP (IO-APIC interrupts use solves the conflict I guess).
Anyway, as I said, the gentoo install kernel is a generic 2.4.26, without SMP, and the speed was the same. But maybe cpufreq was also activated, I'm going to try without, as said below.

UPDATE: I've tried with cpufreq disabled, it gives the same results, also without ACPI. I'm pretty sure it's an hardware problem at this point, due to motherboard relpacement.

Message Edited by kerso on 08-30-2004 02:53 PM

seancoates · Answer

I had what seems to be the exact same problem, see my post, here: http://forums.us.dell.com/supportforums/board/message?board.id=insp_general&message.id=148354 Maybe you got my dud. (-: S

Agent Orange · Answer

this could be a problem with the bios. the bios holds the DSDT tables which the system uses to figure out what your hardware is and how to use it with ACPI. This may be the problem - but it's just a wild guess.

another thing to look at are the files in /sys/devices/system/cpu/cpu0/cpufreq/ which will tell you what scaling etc that cpufreqd is using. might be some leads in there.

Linux General

Was this post helpful?