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Pentium 4 with FSB 533 MHz in the test: Intel sets new standards

Pentium 4 with FSB 533 MHz in the test: Intel sets new standards

Table of contents
  1. 1 Foreword
  2. 2 Technology
  3. 3 Bandwidth
  4. 4 Power consumption
  5. 5 Requirements
  6. Overclocking
  7. 6 Test system
  8. Benchmarks
    1. 7 Boottime
    2. Sandra 2002
    3. 8 PCMark 2002
    4. 3DMark 2001SE
    5. 9 GLMark
    6. 10 Quake 3 Arena
    7. 11 Sysmark 2002
    8. 12 Seti @ Home
    9. WinACE
    10. 13 FlaskMPEG
    11. Lame
    12. 14 Cinema 4D
    13. 15 ViewPref
    14. 16 Lightwave
  9. 17 Pricing
  10. 18 Conclusion

Bandwidth

Since in the past we were less concerned with the bandwidths of the bus systems, At this point I would like to briefly discuss some of the basics and why they are so important. Since a processor can process more and more data with increasing clock rate, it is important that it can also be supplied with sufficient data per cycle or per second. What use is the fastest processor if it cannot be supplied with data quickly enough? You also have nothing from an immensely high memory bandwidth if the processor is not able to process the incoming data or the connection of the processor is simply so bad that the data cannot even reach the processor.

The Pentium 4 is connected to the Northbridge, with Intel the Memory Controller Hub (MCH), via a 64-bit bus. Intel is able to get on this busto transmit a total of four pieces of data information per cycle. The bandwidth of the bus for the Pentium 4 processors can be calculated as follows:

  • 400MHz: 64 bit bus width * 100 MHz bus clock * 4 data packets = 25,600 Mbit per second
  • 533MHz : 64 bit bus width * 133 MHz bus clock * 4 data packets = 34048 Mbit per second

The result divided by 8 to get to bytes per second gives a bandwidth of the system bus of 3 as mentioned before , 2 and 4.2 GB per second, respectively. The new Pentium 4 can send or receive 4.2 GB per second. It therefore largely depends on the Memory Controller Hub (MCH) how high the system performance is ultimately with the Pentium 4. In the case of the MCH or the Northbridge, the data from the main memory, the AGP bus and all other system components converge. The most important factor here is certainly the main memory, as this is where open applications are 'stored'. Basically, it can be said that the main memory has a significant influence on the overall system performance. Both the graphics card and the other components only play a subordinate role, especially in modern systems.

The introduction of the Accelerated Graphics Port (AGP) was originally used to improve the connection between the graphics card and the main memory, so that these textures can be swapped out 'faster'. For this reason, the clock frequency of the AGP has been doubled compared to the PCI from 33 MHz to 66 MHz. Since it is still a 32-bit bus, it was possible to increase the bandwidth from 133 MB/s with PCI to 266 MB/s with AGP 1x. In the meantime, with the help of little tricks, you can send or receive four data packets per cycle with AGP, which means that the bandwidth with AGP 4x has increased to a little more than 1 GB per second. But already with the step from AGP 2x to AGP 4x you could despite doublingobserved only slight increases in performance over the theoretical bandwidth. But why?

One reason for this is certainly the fact that modern graphics cards no longer have to store any textures in the main memory due to their large graphics card memory. Since the processor no longer has to be used for transformation or light calculations (keyword T&L), less data also has to be exchanged between processor and graphics card. This means that only a fraction of the theoretical bus load of 1 GB/s is left.

This makes it clear that the connection to the main memory is particularly important. Since the data read from hard disks or CD-ROM drives initially end up in the main memory, the main memory is the instance that has a major influence on system performance. In order to allow the Pentium 4 with a bus connection of 3.2 or 4.2 GB/s its full performance, it needs fast working memory. For this reason, with the introduction of the Pentium 4, Intel decided on Rambus as the storage technology. Only this was able to deliver the bandwidth for the Pentium 4 with 400 MHz FSB at the time of its market launch. Rambus with a clock rate of 400 MHz (PC800) can achieve a bandwidth of 3.2 GB/s. In order to supply the new 533 MHz Pentium 4 with enough data, there is a so-called PC1066 Rambus which theoretically can achieve a bandwidth of 4.2 GB/s. However, Intel's new Rambus chipset officially only supports the slower Rambus, but the faster version still runs completely stable on such boards, so that manufacturers like Asus even advertise their products based on it with such Rambus support.

However, Rambus is still not enjoying the popularity that Intel wanted, although the memory is no longer more expensive than good DDR SDRAM in terms of price is. ThereHowever, Rambus is still the first choice for Intel in the high-performance area, the new Pentium 4 with a front-side bus of 533MHz is also initially starting with a new Rambus chipset (i850-E). However, Intel will shortly present a DDR SDRAM chipset (i845-E), which is also suitable for the new Pentium 4 with 533 MHz. However, this will not be able to develop the full power of the Pentium 4. The i845-E will only support working memory according to PC200 and PC266 standards. The bandwidth of the PC266 is, without wanting to open large bills at this point, only 2.1 GB per second. When it comes down to it, simply too little for the old Pentium 4 and especially for the new Pentium 4, since the bandwidth increase cannot be used in this case. Even PC333 memory, which is supported by some Pentium 4 chipsets such as the SiS 645DX or the VIA P4X333, is not yet fast enough with its 2.7 GB per second. How big the difference in performance really is in practice will be shown in a later review.

Incidentally, with the AMD Athlon XP we also have a 64-bit bus. This is clocked at 133 MHz and works with the double data rate method. In this way, the Athlon XP can communicate with the Northbridge with a bandwidth of 2.1 GB per second. Thus, DDR SDRAM according to the PC266 standard with its 2.1 GB/s can supply the Athlon with enough data. The use of faster main memory such as PC333 therefore only has a small effect on the overall performance of an Athlon system. However, a small increase in performance can still be seen, since normally not only the processor accesses the main memory. This information is only marginal.

On the next page: Power consumption

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