freebsd-performance Digest, Vol 3, Issue 11

[David O'Brien]

On Thu, May 22, 2003 at 09:14:45AM +0200, Pavel Kraynyukhov wrote:
> As far as i know HyperThreading is an Intel trademark and technologie as
> well.
> AMD has something similar for them processors, but i have no idea is such
> feature supported by FreeBSD for AMD processors.

I can tell you with upmost authority that AMD does not have something
like HyperThreading in its CPU's -- not even in K8.


> > I gotta question. I am contemplating buying the new AMD Opteron for a
> > newer FreeBSD server. I am certain because of it's x86 compatibility
> > running FBSD won't be a problem,

Nope, no problems:

FreeBSD 5.1-BETA #9: Thu May 22 09:20:08 GMT 2003
    root at k8.amd.com:/hammer/sys/amd64/compile/GENERIC

CPU: AuthenticAMD AMD64 Class Processor
  Origin = "AuthenticAMD"  Id = 0xf40  Stepping = 0
  Features=0x78bfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CM
    OV,PAT,PSE36,CLFLUSH,MMX,FXSR,SSE,SSE2>
AMD Features=0xe0500000<<b20>,AMIE,<b29>,DSP,3DNow!>


# file /boot/kernel/kernel
/boot/kernel/kernel: ELF 64-bit LSB executable, AMD x86-64, version 1 (FreeBSD),
 dynamically linked (uses shared libs), not stripped


> > and I know that there is a 64Bit Apache
> > underways, but is there any 64 bit MySQL Server on the way? Or does MySQL
> > compile with that option? I am certain it can be built with Hyper
> > Threading, but can that help performance on a single 64 bit CPU? Please
> > help! (before I invest :-))

It will perform very well -- HyperThreading does is not the same as
having two real processors.  Some apps do perform better on a
HyperThreaded CPU, others don't.