How Fast Is The 400 MHz Pentium* II Processor?
By Wilson Chan
Intel formally announced their fastest processors--the 350 and 400 MHz Pentium* II processors--on April 15th. Harmony Central put together a system to see how fast the 400 MHz processor really is. The result? We found the processor to be 50% to 100% faster than the 266 MHz Pentium II processor that was announced a year ago. Time to upgrade, guys!
100 MHz Bus
The most significant feature of the two new processors is the faster 100 MHz "front-side bus". The front-side bus is the set of wires that connects the processor to the chipset and memory. The frequency of this bus had been stuck at 60 or 66 MHz since the very first Pentium chip came out in 1993. The jump from 66 MHz to 100 MHz means that the processor can get data to and from memory a lot faster. 100 MHz also happens to fall right in the middle of the FM radio spectrum. If the chassis is not properly designed, the system can interfere with radio reception!
And for all you hardware geeks out there, we ran the STREAM benchmark which measures the memory bandwidth of a system. The 400 MHz Pentium II system has a bandwidth of about 300 MB/s doing COPY, SCALE, ADD and TRIAD. As a comparison, the single-processor SGI* Origin 2000*'s bandwidth is about 300 MB/s, Apple* PowerMac* 266 MHz G3*'s is about 140 MB/s and, finally, the single-processor Cray* T94* supercomputer's bandwidth is about 10 GB/s.
[Note: If you feel compelled to reply at this point to say how fast the PowerMac G3 is, let me repeat: the STREAM benchmark measures the memory bandwidth of a system. It is FACT that the PowerMac 266 MHz G3 has a 66MHz bus and the 350/400MHz Pentium II had a 100MHz. We are not saying the PowerMac G3 is slower in other benchmarks or applications. See PC Week for iMac vs. Intel benchmark results.]
How We Tested
We were looking for a program that stresses the processor/memory system and found Sonic Foundry's Sound Forge* and Ziff-Davis' CPUmark32 seem to fit the bill the best. Sound Forge is a very comprehensive audio processing tool that runs on both Windows 95* and NT*. It can do noise reduction, EQ, pitch shift, acoustics modeling, reverb, and tons of other functions. If you haven't seen it, try out the demo copy. CPUmark32, part of Winbench* 98, is a benchmark written by the publisher of PC Magazine* and PC Week*. It tests only the processor and memory system and does not measure the disk or graphic system at all.
The two systems that we ran the benchmarks on are very similar in configurations. One system contains a 266 MHz Pentium II processor, the other uses a 400 MHz Pentium II processor. One other major difference is the memory (DRAM) used. The 266 MHz system uses EDO memory and the other uses SDRAM. As mentioned before, the 266 MHz system has a 66 MHz system bus versus the 100 MHz in the 400 MHz system.
We picked a 19-second stereo sound clip from our MusikMesse '98 Coverage and ran it through three compute-intensive functions in Sound Forge: Noise Reduction, Pitch Shift, and Acoustics Modeler. Sound clips and detailed description of the tests are available here.
Noise Reduction is designed to remove background noise such as tape hiss, electrical hum, and machinery rumble from sound recordings. Pitch Shift changes the pitch of a sound clip with or without preserving the duration of the clip. In our case, we preserved the duration of our sound clip since this requires more computation than the other case. Acoustics Modeler is "a digital signal-processing tool that adds the acoustical coloration of real environments and sound altering devices to existing recordings." In other words, you can make your recording sound like it's being played in Carnegie Hall, the Capitol, or your bathroom. The Acoustics Modeler CD comes with a bunch of acoustic signatures. If they are not enough, the manual also shows you how to create your own.
Results
| 266 MHz Pentium* II System | 400 MHz Pentium II System | Percent Faster | |
| Noise Reduction | 10.476 seconds | 6.040 seconds | 73% |
| Pitch Shift | 9.509 seconds | 5.701 seconds | 67% |
| Acoustics Modeler (Masonic Center) | 15.019 seconds | 7.250 seconds | 107% |
| Acoustics Modeler (Capitol) | 17.854 seconds | 9.248 seconds | 93% |
| CPUmark32* (higher is better) | 669 | 986 | 47% |
As you can see from the above table, the 400 MHz Pentium II system is about 50% to 100% faster than the 266 MHz system. We are not quite sure why a 50% boost in clock speed (from 266 MHz to 400 MHz) results in a 107% jump in performance. One possible explanation is that the newer (0.25 um) version of the Pentium II processor has a faster floating-point unit than the older (0.35 um) version. If you have time, compare the "fppp" results of the 300 MHz to the 333 MHz.
For More Information....
on the performance of Intel processors
- Intel Processor & System Performance -- Intel's benchmark page
- the Standard Performance Evaluation Corporation -- one of the most widely used benchmarks
- Business Application Performance Corporation -- another popular benchmarks for business environment
on the software programs used in this article
- Sonic Foundry -- maker of Sound Forge, a very comprehensive audio processing software
- ZDBop -- Ziff-Davis Benchmark Operation tests products for PC Magazine, PC Week, etc.
- STREAM -- benchmark for measuring memory bandwidth
*All other brands and names are property of their respective owners.