Re: Bogomips on AMD X2 (was Re:)

From: Michael Concannon
Date: Wed Sep 21 2005 - 08:58:34 EST


Robert.Boermans@xxxxxxxxxxxx wrote:

On Wednesday 21 September 2005 16:20, Robert.Boermans@xxxxxxxxxxxx wrote:


Hello,

I noticed that the bogomips results for the two cores on my machine are consistently not the same, the second one is always reported slightly faster, it's a small difference and I saw the same in a posted dmesg

from

somebody else on the list. Which made me wonder:


I guess it's a cache warming effect. Please show the numbers.
--
vda

Probably not, got this one from a web site, and on this one the first core seems to be faster (can't check my own machine it's off and at home and I'm at work.) The difference I get is similar, but always with the second one faster. It's the same when using cat on /proc/cpuinfo. Oh and I saw it on 2.6.11 and 2.6.12 as supplied with fedora core 4 myself.

Calibrating delay using timer specific routine.. 4014.73 BogoMIPS (lpj=8029470)
Mount-cache hash table entries: 512
CPU: L1 I Cache: 64K (64 bytes/line), D cache 64K (64 bytes/line)
CPU: L2 Cache: 512K (64 bytes/line)
CPU 0(2) -> Core 0
Intel machine check architecture supported.
Intel machine check reporting enabled on CPU#0.
mtrr: v2.0 (20020519)
Enabling fast FPU save and restore... done.
Enabling unmasked SIMD FPU exception support... done.
Checking 'hlt' instruction... OK.
CPU0: AMD Athlon(tm) 64 X2 Dual Core Processor 3800+ stepping 02
Booting processor 1/1 eip 2000
Initializing CPU#1
Calibrating delay using timer specific routine.. 4005.37 BogoMIPS (lpj=8010751)
CPU: L1 I Cache: 64K (64 bytes/line), D cache 64K (64 bytes/line)
CPU: L2 Cache: 512K (64 bytes/line)
CPU 1(2) -> Core 1
Intel machine check architecture supported.
Intel machine check reporting enabled on CPU#1.
CPU1: AMD Athlon(tm) 64 X2 Dual Core Processor 3800+ stepping 02
Total of 2 processors activated (8020.11 BogoMIPS).

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



opposite result here - 2nd one is faster (from /proc/cpuinfo):
processor : 0
vendor_id : AuthenticAMD
model name : AMD Athlon(tm) 64 X2 Dual Core Processor 4400+
cpu MHz : 2211.337
bogomips : 4374.52
...
processor : 1
vendor_id : AuthenticAMD
model name : AMD Athlon(tm) 64 X2 Dual Core Processor 4400+
cpu MHz : 2211.337
...
bogomips : 4407.29

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/