Intel flaunts FPU strength of Pentium 4 by SPEC CFP2000

tnaw_xtennis

Intel on Monday will introduce its Pentium 4 processor at 1.4GHz and 1.5GHz clock speeds
at $644 and $819. An introductory offere of CPU, D850GB mobo and two 64Mb PC800 Rambus
RIMMs is provided. The largest surprise that Pentium 4 benchmarking results will bring to us should
be the Pentium 4 having the highest SPEC CFP2000 performance of any PC processor
that's out there. "And, in fact, Pentium 4 compare very favorably to a lot of RISC microprocessors
which for so long have been resident in things like workstations." Paul Otellini, executive vice
president and general manager of the Intel Architecture Group, said.

As suggested by Intel, many review sites will use SPEC CFP2000,  a long run times and large
problem benchmark produced by SPEC which contains 14 applications for measuring floating
point performance of the computer's processor, memory architecture and compiler, for the first
time to usher FPU strength of the Pentium 4 thoroughly. According to the data from Daniel Rutter,
our testing and SPEC, we would like to delivery the first unveiled posted concerning the directly
SPEC CFP2000 performance comparison between the Pentium 4 and Athlon Thunderbird.

In our point of view, the most important factor that makes Pentium 4 shine in CFP2000 is
the 400MHz FSB (Front Side Bus) it applied. Since most of the testes in CFP2000 deals with
large date set which stress system and memory bus bandwidth performance than the computational
testes that stress the FPU performance of the processor. In the applications such as 3DStudio
Max rendering that are very floating point intensive and not very stressful on the system
and memory bus, Athlon Thunderbird will still have a very competitive performance in
rivaling with Pentium 4.

The figure below shows the SPECfp2000 performances of top CPUs from AMD and Intel.

Pentium 4 1.4GHz and Pentium 4 1.5GHz have +36% and +41% better SPECfp2000
performances respectively over 1.2GHz Ahtlon Thunderbird, the fastest AMD CPU today,
runs with DDR SDRAM. While compared with Pentium 3 1GHz (Intel VC820, PC800 RDRAM),
they have +72% and +79% performance boosts.

The influence of FSB on the SPECfp2000 performances is indicated in the table. The results shows
clearly that most of the testes in CFP2000 depend heavily on the system bus bandwidth performance.
Increasing the FSB of the Pentium 3 800MHz system from 100MHz to 133MHz, a +8%
SPECfp2000 performance improvement was gained.

SPECfp2000 Results of Pentium III (coppermine) 800 MHz with different FSB*
Benchmark Category FSB
100MHz		 FSB
133MHz		 Performance gained
with faster FSB (%)
168.wupwise Physics / Quantum Chromodynamics 288 296 2.8
171.swim Shallow Water Modeling 267 365 36.5
172.mgrid Multi-grid Solver: 3D Potential Field 189 210 11.1
173.applu Parabolic / Elliptic Partial Differential Equations 188 206 9.6
177.mesa 3-D Graphics Library 309 316 2.3
178.galgel Computational Fluid Dynamics 247 284 15.0
179.art Image Recognition / Neural Networks 262 298 13.7
183.equake Seismic Wave Propagation Simulation 271 276 1.8
187.facerec Image Processing: Face Recognition 217 220 1.4
188.ammp Computational Chemistry 260 260 0.0
189.lucas Number Theory / Primality Testing 239 258 7.9
191.fma3d Finite-element Crash Simulation 237 244 3.0
200.sixtrack High Energy Nuclear Physics Accelerator Design 139 140 0.7
301.apsi Meteorology: Pollutant Distribution 269 292 8.6

Floating Point Performance - SPECfp2000

 237 256 8.0
* Source: Pentium III 800 (100MHz) and Pentium 800 (133MHz)

 

Now, we will use the extrapolation to find out how much performance boost could be obtained when
increasing the FSB from 133MHz to 400MHz, which is applied by Pentium 4 system, and then do
some explanation to the fact that Pentium 4 1.4GHz and Pentium 4 1.5GHz have up to +72% and +79%
SPECfp2000 performance boosts over Pentium 3 1GHz.

The extrapolation applied here has been proved to be quite advisable. In the last posted, we got a
Quakes3 performance number of 210 for a Pentium 4 1.4GHz system by the extrapolation. A week later,
we were very happy to see that Daniel Rutter posted a Quakes3 performance number of 202.3 obtained
by a real Quake3 benchmarking test.

 

From the extrapolation shows in the above figure, a +50% SPECfp2000 performance boost could
be obtained when changing the FSB from 133MHz to 400MHz. This is close to the +46% Quake3
performance boost extrapolated results with increasing FSB speed to the same extent.

 

 

According to the Intel CPU performance formula:
Performance = MHz (CPU clock frequency)x IPC (instructions executed per clock)
and the goals of Pentium 4 design: maintaining an average IPC that was within approximately 10%
to 20% of the P6 micro-architecture. Since floating point application tend to have branches that are
very predictable, and thus naturally have a higher average IPC potential. Therefore, in the floating point
performance - SPECfp2000 extrapolated, we designate that the IPC of Pentium 4 to be 90% of Pentium 3
at the same core speed. Considering the memory bandwidth improvement from 1.6GB/s to 3.2GB/s will
boost SPECfp2000 performance +7% [ value obtained by the fact: SPECfp2000=335 (1 GHz Pentium III,
Intel OR840); SPECfp2000=314 (1 GHz Pentium III, Intel VC820) ]

Now we got the SPECfp2000 performances of Pentium 4 1.4GHz and Pentium 4 1.5GHz

P4 1400 = P3 1400 (400MHz) x 90% x 1.07% = P3 1400 (133MHz) x 150% x 90% x 1.07%
               =367x 150% x 90% x 1.07
               =530 (2.3% less than the test results 541)

P4 1500 = P3 1500 (400MHz) x 90% x 1.07% = P3 1500 (133MHz) x 150% x 90% x 1.07%
               =380x 150% x 90% x 1.07
               =549 (2.3% less than the test results 562)

The above extrapolated results seems to prove once again the most important factor that makes Pentium 4 shine
is the 400MHz FSB it applied.

 

Links of Turning your GeForce/GeForce2 into a Quadro/Quadro2 click!

1.4GHz Pentium 4 vs. 1.2GHz Athlon Thunderbird with DDR SDRAM ( 05/11/2000 )

400MHz FSB Makes the Pentium 4 Shine ( 08/11/2000)