[parisc-linux] Linux/PA-RISC speed (was Re: C240 Graphics, 64bit kernel and more)

Markus Grabert xam@student.cs.ucc.ie
Thu, 15 Nov 2001 14:08:46 +0000 (GMT)

Jurriaan Kalkman wrote:

>>Are you aware of any other gcc/binutils bugs or should
>>gcc/binutils NOW create proper executables for pa2.0 and
>>pa1.1 (including the old CPUs like 730's PCX-S CPU) ?
> There are still bugs.

But Grand Grundler wrote:

| Yes - should work fine. Note one can build 32-bit PA2.0 binaries.
| The scheduling and insns are optimized for PA2.0 CPU but will
| run in "narrow" mode.

Mhh who's right ? I tend to believe Grand.

Of course there are bugs in binutils/gcc. But are there KNOW bugs/issues
a software developer (not a kernel freak) has to be aware of ?
What about glibc ?
Are threads fully supported ? Are gcc's ObjC, Java and C++ compilers
also working ?

>>I can imagine that the Linux/HPPA kernel is not very optimized yet
>>(can't compare the speed on my 730 with HP/UX since I don't
>>have the OS software anymore ...). Is the speed difference just a
>>few percent or can you 'feel' it (mhh, fuzzy question) ?
> I can only say that compiling a kernel on my C200 takes about 2 times
> as long as on my alpha (21164, 500 Mhz, 2 Mb cache). I feel it should
> be faster.

That's odd.
A 21164/500MHz (not 21164A or 21164PC) is slower according to
Spec_INT95, Spec_FP95 and the Spec_base(INT|FP)95 variants.

Indeed the benchmarks say that the Alpha is about 50% slower for FP stuff

and just a little bit slower for INT stuff (compared to a C240 HP/UX).

Moreover, according to SPEC:
If you compare it to a Intel CPU, the PA8200/236Mhz seem to be as fast as
a Pentium II 400-450 for integer operations and as fast as a
Pentium III 750-800 for floating point operations.

Well, lies, bigger lies/statistics and benchmarks.
Don't trust them.
Nevertheless a factor of 2 shouldn't occur. It's a too big number.
Is it just for compiling the kernel or for every application ?

greetings Max

> Good luck,
> Jurriaan