> > On the 3rd machine, it seems to be abnormal :
> >
> > - Win98 (same as above)
> > - Pentium III 650, 1.65 V, L1 and L2 activated (I verified the BIOS)
> > - 128 Mb ram, 20 gigs UDMA 4
> > - MB: Asus CUV4X (agp 4x bus, not a cheap one), Xentor 16Mb video ... -
No
> > abnormal process running (same antivirus as other machines, etc.) - P
> > 9264797 => 0.231 (George's gives 0.190)
> 1) All systems using SDRAM & the Intel 820 chipset seem to be very
> disappointing. The 820 chipset was designed to use RDRAM and the
> required "translation" in the memory bus slows things down somewhat.
This cheaper version of this Asus CUV4X MB uses the VIA 82C chips : I am
now very happy not having paid the extra 100 $ to buy the Asus Intel's
version, which as you say may have given the same result !
> 2) A PIII-650 has 100 MHz memory bus speed, just like a PIII-500.
> Since Prime95 drives the memory bus quite hard, perhaps one shouldn't
> expect too much speed increase. Especially when you have the 820
> chipset MTH bottleneck in the circuit.
I understand. I didn't think at Prime95 so much using the bus (in fact, in
Paris the Metro is far more convenient). I was also not aware that a new MB
could make a bottleneck to a not-so-recent processor... I do appreciate
Asus for years because they are very reliable (imho), but now i'm kind of
deceived.
> 3) The smaller cache in the PIII-650E relative to the "old" PIII-650
> (which ran at 2.0V with 512K L2 cache at 0.5x core speed) will result
> in increased loading on the memory bus, which may more than offset
> the clocks saved by the improved cache design.
Ho ho, another tricky point here. It seems to me this 256K PIII wind up
beeing another kind of "light" version of a serious cpu. Decreasing cache
size may be just like gluing a tape on the border of a large 21" screen to
make a 15" of it ?
George also talked about sdram speed, it may be the point too.
> Commercial benchmarks exercise the graphics & disk subsystems as well
> as the memory subsystem (in fact a lot will run in the L2 cache); the
> extra raw speed will definitely help boost these benchmark figures,
> even if Prime95 speed remains depressed.
OK i'll check if I can find some serious testing around the
memory/cache/bus/sdram ... in fact, we got it, it's called Prime95, thanks
to George. By the way, why not making a special version of Prime (with no
net connection), that does only the testing of a number of iterations on
some different numbers (defined in the ini file), and either give this
program as a "comparative mesurement" of machines, and/or have a site that
takes the users measures and publish "average" result depending of
materials ?
So we could know if a solution is good before we buy...
> I've switched to Athlon since the Athlon memory bus design is
> superior even if the cache is slower. My Athlon 650 is turning in
> Prime95 performance equivalent to George's PII-400 scaled up to 750
> MHz.
Congratulations Brian. But in fact, even if I run my 5 machines 24h, they
don't serve me for Prime95 only (i'm poor). This PIII 650 seems to be quite
good for 3D calculations, PAO and graphics (along with a good agp card).
So, i'm not so complaining. Even if understand in a general meaning it may
be closer say to a 555 then a 650...
Sylvain Perez
PS: my fault, I forgot to put an objet to the initial email, this gives the
present awfull title of this thread.
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