New Products from Intel: Intel Pentium 4 3.0GHz with 800MHz Quad Pumped Bus, Intel 875 and Intel 865 Chipsets Review

by Ilya Gavrichenkov
04/13/2003 | 12:09 PM

The competition in the CPU market hasn’t become any weaker. Despite the fact that both major processor developers, AMD and Intel, have almost run out of the scalability potential of their current processor cores, the companies keep on the armament drive by seeking new ways to speed up their CPUs. The shift to new 90nm technology, which will allow increasing the CPU clock frequencies further on without any difficulty, is expected to take place only in the end of this year – beginning of the next year. Therefore, the only weapon for the CPU developers will be the processor bus frequency increase, which doesn’t require and changes in the processor core.

Today Intel announced its new Intel Pentium 4 3.0GHz processor, which appeared the first solution supporting 800MHz Quad Pumped Bus. This way the processor bus bandwidth of the today’s fastest Pentium 4 models has been increased up to an impressive value of 6.4GB/sec. to load this bus with work Intel has also developed two new chipsets: i875 and i865 supporting dual-channel DDR400 SDRAM. This memory subsystem guarantees the bandwidth of the same 6.4GB/sec.

Pentium 4 3.0GHz processor, which has been just launched, will be not the only processor featuring such a fast bus. Intel is planning to push 800MHz Quad Pumped Bus very actively into the industry, so that to make it and Hyper-Threading technology widely spread. All Intel CPUs to be announced after today will support Hyper-Threading technology and feature fast processor bus. As we see, Intel’s policy is highly flexible. If you remember, last autumn the microprocessor giant hasn’t even mentioned the 800MHz bus and claimed that Hyper-Threading technology will be implemented only in CPUs working at over 3GHz core clock. However, the latest event’s, which had happened in the memory market lately, pushed Intel to undertake some serious measures to improve the performance of their flagman CPU family.

Pentium 4 CPUs with 3.0GHz core frequency, 800MHz bus and Hyper-Threading technology support will be available string from today, and a bit later in the second half of May more CPUs of the kind will come out. The new processors to be launched in the second half of May will work at 2.4GHz, 2.6GHz and 2.8GHz. Here we would like to draw your attention to the fact that Hyper-Threading technology will be enabled in all Pentium 4 processors with 800MHz bus, but the only CPU with 533MHz bus and Hyper-Threading technology will still remain Pentium 4 3.06GHz launched last year. Moreover, Pentium 4 processor family supporting both: 400MHz and 533MHz bus will stop developing, although Intel will still supply these CPUs for the  lower market segments. This approach will help the company transfer the entire industry to CPUs with 800MHz bus very quickly. According to the preliminary forecasts, in Q3 2003 35% of all Intel processors will already support 800MHz bus, and by the end of the year this number will grow up to 60%.

This way, the enhancements introduced to Intel’s processors will let the company raise the performance bar a little higher again. First time they did it by introducing Hyper-Threading technology. At that time an only 5% die size increase resulted into a significant performance improvement in a number of multi-threaded applications. Almost the same thing happens when we shift from 533MHz bus to faster 800MHz one. The specific internal architecture of the Pentium 4 Quad Pumped Bus implies that the addresses are transferred via it twice per clock, and the data – four times per clock. Therefore, the effective data transfer rate through the Pentium 4 bus can be easily increased by just raising the FSB frequency on mainboards up to 200MHz. However, the performance of systems with 800MHz bus should become significantly better. Why does Intel so urgently want to increase its CPUs performance ASAP, without even waiting for the new processor family on 90nm Prescott core to come (which is scheduled for the end of this year already)? One of the possible answers to this question is Intel’s vital desire to be able to respond to its major competitor’s, AMD’s, actions. As you remember, AMD was going to start shipping this spring its new generation processors based on Hammer architecture and using x86-64bit technology. For example, we could prove this statement by the fact that the first Hammer based processor models will also feature 6.4GB/sec bus bandwidth, just like the new Pentium 4 CPUs. Therefore, Intel does an absolutely correct thing from the marketing prospective: they don’t want to let the competitor outpace them anywhere.

However, Intel’s concerns about AMD introducing a new Athlon 64 processor generation based on Hammer architecture into the mass market didn’t come true. AMD decided to postpone the launching of their x86-64 processors until this fall. Intel, however, has already announced its definite intention to introduce 800MHz bus all over the place and didn’t want to give up its plans, therefore 800MHz bus appeared in Pentium 4 processors earlier than the competing processor solutions with the same bus from AMD.

Nevertheless, AMD is still going to respond to the launching of Pentium 4 3.0GHz with 800MHz bus and Hyper-Threading technology before the coming fall. In the nearest future the company will announce another Athlon XP processor based on Barton core and supporting 400MHz bus. This CPU will be rated as 3200+ and will work at the actual 2.2GHz. Anyway, we will have another opportunity to talk about this product, and today our story is about Intel.

New Chipsets: Intel 875 and Intel 865

As we have already said above, new Pentium 4 3.0GHz processors launched today do not boast anything new from the technological point of view. The core they are based on remained the same: it is the same good old Northwood, which is used in Pentium 4 3.06GHz with Hyper-Threading support. The only thing different in the new Pentium 4 3.0GHz compared to the predecessor is the multiplier. Pentium 4 3.06 uses 23x multiplier, while the newcomer – 15x.

That is why the only thing Intel had to do to implement 800MHz bus support in the new CPUs was to make sure that they are supported by the chipsets and mainboards available in the market. This is exactly the reason why very soon we will see new i875 (Canterwood) and i865 (Springdale) core logic sets, which will not only support faster bus but also allowing the use of adequate memory subsystem built of dual-channel DDR SDRAM.

For Intel the launching of the new i875 and i865 chipset families will mean successful getting past another point in Pentium 4 platforms and NetBurst architecture evolution. The first Pentium 4 processors featured 256KB L2 cache and 400MHz system bus. Later on, as the company shifted to 0.13micron technology the L2 cache size of Pentium 4 processors grew up to 512KB and the Quad Pumped Bus frequency – to 533MHz. the chipsets developed specifically for these processors have already acquired some innovations by then: they features support for USB 2.0 protocol and worked with DDR SDRAM, which was getting more and more popular. In the end of last year Intel added Hyper-Threading technology to the list of its features and updated its core logic sets having provided them with DDR333 SDRAM support.

The new chipsets, which will be used together with the Pentium 4 CPUs supporting faster bus, will boast a few innovations. Among them we could list the following:

• 800MHz system bus support;
• Dual-channel DDR400/DDR333/DDR266 SDRAM;
• PAT (Performance Acceleration Technology);
• Serial ATA protocol and RAID 0 and 1 arrays support;
• CSA (Communication Streaming Architecture) for Gigabit Ethernet;
• Intel Extreme Graphics 2 - updated integrated graphics core;
• AGP 8x.

Let’s dwell on these and some other features now.

800MHz System Bus Support. The higher 6.4GB/sec data transfer rate between the CPU and the chipset allows improving the processor performance due to the fact that it spends less time waiting for the new data. High data feed rate is very important for contemporary Pentium 4 CPUs with NetBurst architecture and Hyper-Threading technology.

Dual-Channel DDR400/DDR333/DDR266 SDRAM. High-speed processor bus requires faster memory subsystem. Therefore, new Intel chipsets will feature a dual-channel DDR SDRAM controller, like the one used in i7205 (Granite Bay) chipset. However, 800MHz processor bus will also require fast memory to be used in the system. In order to provide a data stream fast enough for the 800MHz processor bus, new chipsets will support dual-channel DDR400 SDRAM.

So, it is exactly the two DDR SDRAM channels used in the new platforms with 800MHz Quad Pumped Bus that make these systems well-balanced. No other memory types can cope with the increased processor bus bandwidth.

PAT (Performance Acceleration Technology). This technology is intended to improve the chipsets performance. It speeds up the system by taking advantage of the “internal reserves”. Namely, this technology reduces the latencies when the CPU works with the system memory via the chipset. You don’t need any specific memory modules to make this technology work: all the necessary optimization is made inside the chipset North Bridge and in the BIOS. When the CPU addresses the system memory, the chipset omits some operations typical of other core logic sets and performs certain operations faster.

SerialATA Protocol and RAID 0 and 1 Arrays Support. New Intel chipsets will be equipped with a new South Bridge aka ICH5. It will differ from the ICH4 predecessors by bigger number of USB 2.0 ports (it will support 8 of them), and SerialATA support. It is remarkable but Intel didn’t implement ATA/133 protocol support in its ICH5 South Bridge tending to push the industry towards the newer and more convenient SerialATA interface (read more about SerialATA interface and its advantages in our Seagate Barracuda Serial ATA V HDD Review).

ICH5 supports a pair of SerialATA-150 channels. It means that you can now connect to ICH5 up to 6 ATA devices (keeping in mind two ATA/100 channels inherited from the ICH4 predecessor). It is also very important to point out that ICH5 will be the world’s first South Bridge with the integrated RAID functions support. A special version of this bridge aka ICH5R (Intel 82801 ER), which will be only $3 more expensive than the regular version, will support RAID 0 (striping). Although you will be able to build up a RAID array only of SerialATA HDDs, you will be able to do it any time: no OS reinstallment is necessary.

In the future ICH5R will acquire enhanced features set. It should also start supporting RAID 1 (mirroring) arrays and Windows 2000. so far, RAID function from Intel will work only under Windows XP.

CSA (Communication Streaming Architecture) for Gigabit Ethernet. Since the times of i440LX and until recently North Bridges of almost all chipsets featured 4 buses: processor bus, memory bus, AGP bus and a bus between the North and the South Bridge. Today Intel added one more, fifth, bus to its new chipsets’ North Bridge.

This is a 256MB/sec bus, which is intended for CSA (Communication Streaming Architecture) implementation. It will serve to create high-speed gigabit network connections. The use of a special separate bus for network needs makes the processing of network requests very fast and unloads the CPU quite tangibly. Moreover, CSA allows all network controllers connected to it to work with the memory directly. Intel uses its PRO/1000 CT chip as a network controller within the CSA.

Intel Extreme Graphics 2 - Updated Integrated Graphics Core. Some new chipsets supporting processors with 800MHz bus will also feature an integrated graphics core. In fact, this will be the same Intel Extreme Graphics core, which we have already met in i845GE chipset. However, from now on it will work much faster. It will be achieved due to faster memory subsystem, which will be used by the graphics core for its needs, as well as due to higher working frequency of the graphics core itself.

AGP 8x Support. Following in the footsteps of all chipset manufacturers, Intel now realized the necessity of the AGP 8x graphics bus, because the graphics cards supporting it have already got very popular in the market. This way the new chipset will exchange data with the graphics subsystem at 2.1GB/sec.

Depending on the application field, new i875 and i865 chipsets will have a selected set of the above discussed innovations. Now let’s take a closer look at the two new chipset families and their representatives.

• Intel 875P. Intel targets this chipset for the High-End market segment and for use in the fastest PCs. That is why it will have no integrated graphics core, which is always replaced with a high-performance graphics cards in any high-end PC. All other new features, including PAT, are fully supported. Also we would like to point out that this chipset is the only one of all newcomers with ECC support.

• Intel 865PE. This is the younger brother of i875P, which is targeted for the mass market. It boasts all the same features, except PAT and ECC support.
• Intel 865G. This is a modification of i865PE with an integrated graphics core aka Intel Extreme Graphics 2.
• Intel 865P. This is a “lite” version of i865PE, which doesn’t support 800MHz processor bus.

Intel 845PE Chipset

Speaking about the chipsets to support the new Pentium 4 CPUs with 800MHz processor bus, we should definitely mention i845PE. Although this chipset doesn’t officially support 800MHz Quad Pumped Bus, the practice shows that there re hardly any problems with this chipset using 200MHz FSB. Many mainboard manufacturers took advantage of this fact and announced their products based on i845PE with the 800MHz Quad Pumped Bus support among the specs. Therefore, we have every right to include i845PE in the list of chipsets, which will be able to work with the new Pentium 4 processors.

Of course, unlike i875 or i865, this chipset doesn’t support dual-channel memory. With FSB frequency set to 200MHz, you can only use single-channel DDR400 SDRAM memory. However, there is one very important argument in favor of i845PE as a solution for the new Pentium 4 processors: the price. Even though the new i875 and i865 chipsets do not require the expensive 6-layer PCBs, the engineering expenses during the mainboards production are still quite high. Besides, the chipsets themselves are somewhat more expensive than the good old i845PE. That is why mainboards based on i845PE supporting 800MHz Quad Pumped Bus can turn out quite a good buy, especially in the beginning.

Specifications of Discrete Chipsets Supporting 800MHz Bus

The table below compares three discrete chipsets supporting 800MHz Quad Pumped Bus one way or another. They are: i875P, i865PE and i845PE:

Testbed and Methods

The major goal of this test session was to find out the advantages of the faster 800MHz bus used with the new Pentium 4 processors. Namely, how greatly the Pentium 4 systems performance could improve this way. At the same time we also tested the new i875 and i865 chipsets, and checked the performance of the old buddy i845PE with the system bus overclocked up to 800MHz. As for the new i865 and i875 chipsets, we certainly were very much interested in their performance with different memory types and in the advantages of the PAT technology implemented in i875.

Therefore we tested the following solutions:

• Intel D875PBZ mainboard based on i875P. We tested this mainboard with 533MHz and 800MHz bus frequencies and used DDR400 SDRAM as well as DDR333 and DDR266 SDRAM in dual-channel mode.

• Intel D865PERL based on i865PE. We tested this mainboard the same way as described above.
• ASUS P4PE based on i845PE chipset. This mainboard, which has stood the test of time already, works perfectly well at up to 200MHz FSB, therefore, we managed not only to run the tests for 533MHz bus frequency, but also for 800MHz.

Also for a more illustrative and complete comparison we took the results obtained from an AND Athlon XP 3000+ working in the fastest configuration possible: with NVIDIA nForce2 based mainboard and DDR333 SDRAM.

As a result, out testbeds looked as follows:

All dual-channel chipsets were tested in dual-channel mode. The mainboards BIOS’s were set to get the maximum performance. All benchmarks were run in Windows XP SP1 operation system.

Performance

Before we go to the systems performance in real applications, let’s check how fast the new chipsets work with the memory subsystem. So, let’s resort to the synthetic Cachemem test, which we have been using for a long time now to test the new sets of core logic.

Actually, the results speak for themselves. Nevertheless, I would like to comment on a few things. Firstly, let’s check out how efficient PAT technology implemented in i875 proved. According to the obtained results, the use of this technology allows not only to reduce the latency when the memory is addressed, but also to speed up the reads from the memory. These two factors explain why i875 outperforms i865.

Also we would like to point out that the use of 800MHz bus really does tell on the work with the memory. In particular, even if you use 800MHz FSB and dual-channel DDR266 SDRAM, this combination will prove faster in most tests than a combination of 533MHz FSB and DDR333 despite the equal bandwidth of the bus between the processor and the memory.

The single-channel i845PE chipset demonstrated pretty nice results with 800MHz bus. Its trump is low latency during the work with system memory. This fact may affect its performance in real tasks a lot, so that it could appear not much slower than the dual-channel chipsets.

All in all, the results of the synthetic SiSoft Sandra 2003 benchmark measuring the practical bandwidth of the memory subsystem appear proportional to the theoretical bandwidth of the bus between the CPU and the memory in each particular case.

However, there are a few curious things here. I would like to stress that the practical bandwidth of the i875 chipset is always higher than the results shown by i865, which demonstrates how efficient the PAT technology is. It is also important that the FSB frequency exerts more influence over the path between the CPU and the memory than the memory frequency increase.

Another synthetic benchmark measuring the memory subsystem performance, which we used in our test session, is PCMark2002. In this test i875 also managed to beat i865, with the performance difference in some cases reaching 5-7%. As for the CPU, the processors with 800MHz bus managed to outpace those with 533MHz bus by 13-14%. We would also like to point out that the performance of i865 chipset appeared higher when we took Pentium 4 3.06GHz CPU with 533MHz FSB than that of i875, which indicates pretty clearly that PAT technology is most efficient when the FSB frequency equals 800MHz.

The processor test from the PCMark2002 test set showed that Pentium 4 3.06GHz with 533MHz Quad Pumped Bus was faster than Pentium 4 3.0GHz processor with 800MHz bus. This happened because the core clock frequency of the first CPU was higher: this benchmark almost doesn’t use the memory bus. This way it is hypothetically possible that newer processors will not be faster than their predecessors with 533MHz bus.

Now let’s move from synthetic tests to complex ones.

Office and Content Creation Applications

As we see, in Business Winstone 2003 it is not only data transfer rate between the CPU and the memory that matters: low latency is also of great importance. This is actually why i845PE showed pretty high result here. As we have already said above, when we set the FSB to 200MHz in the i845PE based system, its latency gets very low.

Content Creation Winstone 2003 offers us a slightly different picture. However, Pentium 4 with 800MHz bus manages to show better results than Pentium 4 3.06GHz CPU with 533MHz bus frequency. Although the performance gap between them is not that big: about 2% only. The thing is that applications included into this test package use the memory bus quite actively but at the same time require high actual CPU performance.

Now let’s take a look at the streaming data encoding tasks, which are exactly the tasks where faster bus should play the main role.

And it is absolutely true! As soon as the system acquires 800MHz bus and dual-channel DDR400 SDRAM, the performance boosts significantly. For example, data compression with WinRAR utility gets over 20% faster. By the way, we can also see that the use of 800MHz bus with i845PE chipset doesn’t provide the same advantage any more. Unfortunately, this chipset is a single-channel one and hence the memory bus appears a noticeable bottleneck.

And the fastness of files encoding into MP3 format hardly depends on the memory subsystem performance, as we may see. That is why, just like in CPU benchmark from PCMark2002, Pentium 4 3.06GHz processor outperforms Pentium 4 3.0GHz CPU even despite the slower bus of the former.

When we encode into MPEG-4 format, the picture is totally different. Although the processor speed here is as important as during MP3 encoding, the systems with 800MHz bus are slightly faster than the same systems with 533MHz bus. Also the PAT technology implemented in i875 ensures a certain advantage here.

We see almost the same thing with Windows Media Encoder. By the way, we would like to stress that the new Pentium 4 processors manage to beat AMD Athlon XP 3000+ in all data encoding tasks. Intel CPUs owe this victory to the gigantic Pentium 4 bandwidth as well as to Hyper-Threading technology, which allows using the CPU resources in a much more efficient way.

Now let’s check the performance of our testing participants in gaming applications.

As you remember, AMD Athlon XP 3000+ used to be the fastest in 3DMark2001 SE. However, today the situation changed not in AMD’s favor. Intel Pentium 4 3.0GHz with dual-channel DDR400 appeared faster than the competitor from AMD. Pentium 4 3.0GHz proved also pretty fast with the i845PE chipset. It means that the overclocked i845PE can be used as a basis for a gaming platform as well.

Futuremark 3DMark03 is a benchmark that loads the graphics subsystem very heavily. This is exactly why the results of all platforms tested differ just a tiny bit from one another. Nevertheless, the advantage of the 800MHz bus is evident even here.

It would be much more exciting to check the CPU score index provided by this benchmark. This parameter is obtained during software vertex shaders calculation, which loads not only the CPU, but also the memory subsystem.

Here we see very clearly the advantage of the 800MHz bus as well as the positive effect of the PAT technology. The use of faster bus speeds up Return to Castle Wolfenstein by about 10%, PAT technology implemented in i875 – by about 3%. Also note that high speed memory subsystem is very important for games built on Quake3 engine. As a result the platform built with i845PE chipset and 800MHz bus falls 12% behind i875 based platform. Also note that if you use CPUs with 533MHz bus frequency, i875 and i865 chipsets will perform almost equally fast. So, if you have been considering the purchase of an i875 based mainboard for a system with Pentium 4 processor supporting 533MHz bus, we suggest that you should change your mind.

Almost the same picture appears in Unreal Tournament 2003. The only difference here is the outstandingly high performance of AMD Athlon XP 3000+ processor.

It is pretty interesting how fast new Intel solutions will perform during rendering.

Well, everything is clear: need fast rendering - take a faster CPU. The memory bus speed hardly has any influence on its performance.

The results obtained during rendering in Lightwave 7.5 only prove the supposition made above.

We can’t say anything principally new about rendering with CINEMA4D package. By the by, just look what a failure an AMD Athlon XP 3000+ appears in 3D modeling applications. This situation became a common case after Intel had provided its CPUs with Hyper-Threading technology support. The “virtual multi-processor configurations” implemented with the help of Hyper-Threading improve the performance of the Pentium 4 processor quite a lot, as it allows using its resources in a more efficient way.

And in conclusion, let’s check the systems performance in professional applications using OpenGL.

The results of SPECviewperf 7.1 prove that i875 with dual-channel DDR400 memory and 800MHz bus is an excellent platform for professional tasks.

Conclusion

Let’s sum it all up now. Due to a significant increase in the processor bus frequency of Pentium 4 3.0GHz CPUs, Intel managed to improve the performance of its platforms. If we compare the performance of Pentium 4 3.0GHz with that of competing CPUs, we will see that Intel’s solutions win in a much greater number of applications now. Intel owes its success to the new chipsets supporting dual-channel DDR SDRAM in the first place.

Speaking about the chipset, which we considered in our investigation today, we can say that i875 and i865 are really outstanding products. These chipsets have every chance to become very popular and widely spread. Although they will hardly be able to repeat the success of the legendary i440BX. They life-time is not so long, because in about a year or so new chipsets with DDR II support will come to replace them. However, even despite this fact, i875 and i865 deserve all our compliments. Beside outrageously high performance, these chipsets appeared the first solutions in the industry to support SerialATA and RAID arrays, and featuring an individual bus for high-speed network connections. No doubt that these innovations will be really demanded in the market.

And in conclusion I would like to stress once again that Hyper-Threading technology, which was first introduced in Intel Pentium 4 3.06GHz and now has found its place in the new Pentium 4 3.0GHz, proved to be a really smart way to increase the system performance. This technology allowed speeding up the work in many applications so significantly, that the competing CPUs without it hardly have any chances left. Therefore, it is a very pleasing fact that we will soon see CPUs with lower clock rates than 3GHz featuring this technology.

Well, let’s wait and see if AMD manages to strike back this time. Athlon XP 3200+ and the new Athlon64 family are approaching already...