Re: [gentoo-user] [OT]Real compute cycles in a laptop?

[Mark Knecht]

On 11/7/06, Alan McKinnon <alan@××××××××××××××××.za> wrote:
>
> You seem to know enough about these matters already to make a sane
> judgement, so you probably already know that the real answer to your
> question is "it depends".
>
> Here's what I would do: pop along to your local store, preferably not
> one of the big chains, find the sanest sales guy with a clue and
> explain your problem. Don't listen to his recommendations, just ask if
> you can test his demo machines with the actual app in question. If it's
> an owner run store he probably say yes. Then test the thing for real
> and measure progress after 30 minutes or so. Buy the best performer.
>
> This will take a while, but at least you'll know for real which one
> suits your needs best
>
> alan

Thanks Alan.

The problem with running the neural network app is that it's a huge
install under Windows. It requires Internet access as it has a
hardware key that has to be validated against the specific machine.
Probably takes 1 hour just to set up. Then, once it's set up it takes
maybe 15 minutes to run a single solution on my older Athlon XP 1600+.
With that as background I'm sure you can understand that I'm not
anxious to do it more than once or twice.

What I was hoping to do was find some basic way of comparing the
BogoMIPS on my old Athlon XP machine with BogoMIPS on some new
machines at the dealer. They haven't had any problems in the past with
me bringing in a LiveCD and booting Linux. If I could do this then I
might estimate that the new machine will run the same speed or will
run 3X the speed when doing these neural network jobs?

Here's some info on the machines in my house today:

1) A 3GHz P4HT machine we use as a MythTV backend server and desktop machine:

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 15
model           : 3
model name      : Intel(R) Pentium(R) 4 CPU 3.00GHz
stepping        : 3
cpu MHz         : 2995.346
cache size      : 1024 KB
<SNIP>
bogomips        : 5996.11

processor       : 1
vendor_id       : GenuineIntel
cpu family      : 15
model           : 3
model name      : Intel(R) Pentium(R) 4 CPU 3.00GHz
stepping        : 3
cpu MHz         : 2995.346
cache size      : 1024 KB
<SNIP>
bogomips        : 5990.25

2) My son's AMD Compaq low cost machine:

processor       : 0
vendor_id       : AuthenticAMD
cpu family      : 15
model           : 47
model name      : AMD Sempron(tm) Processor 3200+
stepping        : 2
cpu MHz         : 1803.767
cache size      : 256 KB
<SNIP>
bogomips        : 3611.84

3) 1 of 2 Pundit-R's used as Myth frontend machines:

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 15
model           : 3
model name      : Intel(R) Celeron(R) CPU 2.26GHz
stepping        : 4
cpu MHz         : 2261.847
cache size      : 256 KB
<SNIP>
bogomips        : 4526.57


4) My AMD64 Gentoo machine is use daily:

processor       : 0
vendor_id       : AuthenticAMD
cpu family      : 15
model           : 47
model name      : AMD Athlon(tm) 64 Processor 3000+
stepping        : 0
cpu MHz         : 1809.286
cache size      : 512 KB
<SNIP>
bogomips        : 3619.63

5) The current Athlon XP Windows machine is busy running Trading
Solutions but when in Linux I *think* it has a BogoMIPS spec around
2800. No way to verify that right now.

It's pretty boring but it seems that you can sort of double the CPU
MHz spec and come pretty close to the BogoMIPS numbers. However that
doesn't take cache size into account so maybe BogoMIPS isn't even the
right thing to be looking at.

At the root of it all my questions are:

1) How representative are BogoMIPS in determining how fast a machine
will eventually be on compute bound apps?

2) Are there any good listings of BogoMIPS on different processor
types and speeds? (This is what I really want....)

3) Do BogoMIPS include FPU measurements in case that is important for my app?

4) How well do BogoMIPS translate to the same machine when it runs Win XP?

Anyway, thanks very much for your answers. I appreciate the help even
if it isn't primarily about running Gentoo. I suspect there are others
out there that have to dual boot. Maybe this will help someone in the
future with similar questions.

Cheers,
Mark
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