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DL145 G2, /proc/cpuinfo reports 1.8Ghz, but BIOS says 2.2

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Timothy Carlson
Occasional Advisor

DL145 G2, /proc/cpuinfo reports 1.8Ghz, but BIOS says 2.2

I've got a number of dual dual core 145 G2 boxes running RHEL 4 U2 x86_64. Specific kernel is

2.6.9-34.ELsmp

/proc/cpuinfo says

cpu MHz : 1808.362

But the BIOS reports (and I know I purchased) 2.2Ghz. My grub line is

kernel /boot/vmlinuz-2.6.9-34.ELsmp ro root=LABEL=/ tsc numa=on

removing "tsc" doesn't change the reported values.

Any ideas why the kernel thinks these are 1.8Ghz CPUs?

Thanks
8 REPLIES
TwoProc
Honored Contributor

Re: DL145 G2, /proc/cpuinfo reports 1.8Ghz, but BIOS says 2.2

Just a thought -

Maybe the clock speeds on the system aren't set right, so what the CPU *can* run isn't really what's being run?

What does the "model name:" line say and what does the "cpu Mhz:" line say?

Mine is so exact it says 2800.204 for the "cpu Mhz:" line - which looks to me that it is a computed value - not a copied string.
We are the people our parents warned us about --Jimmy Buffett
Timothy Carlson
Occasional Advisor

Re: DL145 G2, /proc/cpuinfo reports 1.8Ghz, but BIOS says 2.2

THanks!

Here are some numbers.

processor : 3
vendor_id : AuthenticAMD
cpu family : 15
model : 33
model name : Dual Core AMD Opteron(tm) Processor 275
stepping : 2
cpu MHz : 1808.352
cache size : 1024 KB

I have a cluster of 18 of these machines and I am getting an array of different values. Here they are across the cluster.


cpu MHz : 1808.441
cpu MHz : 1808.441
cpu MHz : 2009.289
cpu MHz : 2009.292
cpu MHz : 2210.199
cpu MHz : 2009.262
cpu MHz : 2009.280
cpu MHz : 1808.360
cpu MHz : 2210.221
cpu MHz : 1808.439
cpu MHz : 2009.280
cpu MHz : 2009.267
cpu MHz : 2009.280
cpu MHz : 1808.342
cpu MHz : 1808.345
cpu MHz : 1808.352
cpu MHz : 1808.359
cpu MHz : 1808.352

TwoProc
Honored Contributor

Re: DL145 G2, /proc/cpuinfo reports 1.8Ghz, but BIOS says 2.2

Oh, your posting solves that!

The Opterons are "2200+" - that speed is not a "speed" - that's just a comparable term so that you can see what performance an Opteron will do compared to an Intel...

[pregnant pause]
[crickets]


The speed of an Opteron 2200 is:

1.8 Ghz!

So, I think in your cluster of stuff, you've got a "2200" and a "2400" and a "2600" to explain your various speeds.

HTH
We are the people our parents warned us about --Jimmy Buffett
Timothy Carlson
Occasional Advisor

Re: DL145 G2, /proc/cpuinfo reports 1.8Ghz, but BIOS says 2.2

That would be a bit odd considering I purchased all 18 at the same time and they are all supposedly the same machine, and they are all supposed to be 2.2Ghz boxes (which is what the BIOS reports on a few that I have looked at).



Timothy Carlson
Occasional Advisor

Re: DL145 G2, /proc/cpuinfo reports 1.8Ghz, but BIOS says 2.2

FWIW, on bootup, all of the nodes report the correct Mhz (according to time.c)

time.c: Using 3.579545 MHz PM timer.
time.c: Detected 2210.218 MHz processor.
time.c: Using PM based timekeeping.

Although a few of them are using a different timer.

time.c: Using 25.000000 MHz HPET timer.
time.c: Detected 2210.315 MHz processor.
time.c: Using HPET based timekeeping.

Maybe CPU throttling?

Tim
TwoProc
Honored Contributor

Re: DL145 G2, /proc/cpuinfo reports 1.8Ghz, but BIOS says 2.2

Oh yeah!

There actually is a daemon service running that does exactly what you're talking about that showed up in RH version 4 ( I think ). I f I remember correctly, I turned it off on my server farm. But, at the moment - I can't remember the name of that process that starts in the /etc/rcx.d area...

We are the people our parents warned us about --Jimmy Buffett
Manuel Wolfshant
Trusted Contributor
Solution

Re: DL145 G2, /proc/cpuinfo reports 1.8Ghz, but BIOS says 2.2

it's the cpuspeed daemon, probably. it tries to lower the speed the processors run at any given time in order to minimize power consumption.
Timothy Carlson
Occasional Advisor

Re: DL145 G2, /proc/cpuinfo reports 1.8Ghz, but BIOS says 2.2

Excellent answer. Thanks for all the help! Problem solved.