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Date:      Fri, 25 Apr 2003 09:06:08 -0700
From:      "jeev" <jeev@boldinternet.net>
To:        "'Petri Helenius'" <pete@he.iki.fi>
Cc:        freebsd-smp@freebsd.org
Subject:   RE: Dual 2.40ghz xeon w/hyperthreading
Message-ID:  <000301c30b44$95bc4090$0200a8c0@mainframe>
In-Reply-To: <3EA91BBA.9080104@he.iki.fi>

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Which would give me the best performance? To disable hyperthreading or
enable machdep.cpu_idle_hlt, and if I were to enable it, it would be =
from
loader.conf or?

j

-----Original Message-----
From: owner-freebsd-smp@freebsd.org =
[mailto:owner-freebsd-smp@freebsd.org]
On Behalf Of Petri Helenius
Sent: Friday, April 25, 2003 4:28 AM
To: jeev
Cc: freebsd-smp@freebsd.org
Subject: Re: Dual 2.40ghz xeon w/hyperthreading

jeev wrote:

>Basically guys, this box is not exceeding an ide computer I have on =
idea.
>
>I noticed the dual xeon to be slow. So I ran:
>
>dd if=3D/dev/urandom of=3D/dev/null bs=3D1m count=3D1024
>
>on 2 servers, 1 is the top one and 1 is the xeon.
>Obviously the ide killed the scsi with dual cpu's running =
hyperthreading,
>why?
> =20
>
Hypethreading gives you two virtual CPU's out of one real one. They =
perform
at ~60-70% of the capacity of real one.

Enable machdep.cpu_idle_hlt  (disabled by default on SMP) to have the=20
other virtual
core to execute HLT when it's not doing anything useful except =
busylooping,
which is what happens now.

Or even better, disable hypethreading to recover real performance.

Pete

>
>-SINGLE 2.4ghz p4 w/1gb ram and 80gig ide
>
>1073741824 bytes transferred in 266.387823 secs (4030747 bytes/sec)
>2.4ghz
>CPU: Intel(R) Pentium(R) 4 CPU 2.40GHz (2399.74-MHz 686-class CPU)
>  Origin =3D "GenuineIntel"  Id =3D 0xf27  Stepping =3D 7
>=20
>Features=3D0xbfebf9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,MC=
A,CMO
V
>,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
>real memory  =3D 1073676288 (1048512K bytes)
>avail memory =3D 1039519744 (1015156K bytes)
>ad0: 76319MB <WDC WD800JB-00DUA1> [155061/16/63] at ata0-master UDMA100
>-----------------------
>
>
>
>-dual 2.4ghz xeon each with hyperthreading, 2gb ram ddr, 73gb scsi hd.
>
>1073741824 bytes transferred in 410.476271 secs (2615844 bytes/sec)
>CPU: Intel(R) Xeon(TM) CPU 2.40GHz (2395.92-MHz 686-class CPU)
>  Origin =3D "GenuineIntel"  Id =3D 0xf27  Stepping =3D 7
>Features=3D0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,P=
GE,MC
A
>,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
>  Hyperthreading: 2 logical CPUs
>real memory  =3D 2146959360 (2096640K bytes)
>avail memory =3D 2085502976 (2036624K bytes)
>Programming 24 pins in IOAPIC #0
>IOAPIC #0 intpin 2 -> irq 0
>Programming 24 pins in IOAPIC #1
>Programming 24 pins in IOAPIC #2
>Programming 24 pins in IOAPIC #3
>Programming 24 pins in IOAPIC #4
>FreeBSD/SMP: Multiprocessor motherboard
> cpu0 (BSP): apic id:  0, version: 0x00050014, at 0xfee00000
> cpu1 (AP):  apic id:  6, version: 0x00050014, at 0xfee00000
> cpu2 (AP):  apic id:  1, version: 0x00050014, at 0xfee00000
> cpu3 (AP):  apic id:  7, version: 0x00050014, at 0xfee00000
> io0 (APIC): apic id:  2, version: 0x00178020, at 0xfec00000
> io1 (APIC): apic id:  3, version: 0x00178020, at 0xfec80000
> io2 (APIC): apic id:  4, version: 0x00178020, at 0xfec80400
> io3 (APIC): apic id:  5, version: 0x00178020, at 0xfec81000
> io4 (APIC): apic id:  8, version: 0x00178020, at 0xfec81400
>da0 at ahc0 bus 0 target 0 lun 0
>da0: <SEAGATE ST373307LC 0004> Fixed Direct Access SCSI-3 device=20
>da0: 160.000MB/s transfers (80.000MHz, offset 63, 16bit), Tagged =
Queueing
>Enabled
>da0: 70007MB (143374744 512 byte sectors: 255H 63S/T 8924C)
>
>what could be causing this issue?
>
>Thanks!
>
>j
>
>_______________________________________________
>freebsd-smp@freebsd.org mailing list
>http://lists.freebsd.org/mailman/listinfo/freebsd-smp
>To unsubscribe, send any mail to "freebsd-smp-unsubscribe@freebsd.org"
> =20
>



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