AMD Athlon 1.2GHz with 266MHz FSB

by FastSite
12/26/2000 | 12:00 AM

The end of the year 2000 appeared very rich in events in the CPU market. The situation turned out not that brilliant for Intel recently. After Intel had to call back its Pentium III working at 1.13GHz because of its instability, everybody understood that Coppermine core had already exhausted its potential in terms of clock frequency increasing. AMD, which was carefully following Intel's activities couldn't miss such a perfect chance and easily surpassed its rival having announced 1.1GHz and 1.2GHz Athlon CPUs. However, on 20 November Intel launched a new generation processor, Pentium 4, working at 1.4GHz and 1.5GHz. As you see, this CPU managed to regain the frequency leadership, although its performance was not that impeccable and we wouldn't give Pentium 4 the first prize. Nevertheless, AMD was ready to respond to Intel Pentium 4 and as a stoke back, started manufacturing new Athlon processors with 266MHz FSB and using DDR SDRAM in the platforms for its processors. This is exactly the thing we are going to discuss in the current review: AMD strikes back with a new cool product.<%BANNER[article]%>

We have already discussed some new products and technologies, which have been introduced recently, in our latest reviews on Intel Pentium 4 and Iwill KA266-R Mainboard. However, there are still a couple of things worth mentioning, which we didn't even touch upon. Therefore, we will try to cover a number of other interesting things in our today's review of AMD Athlon 1.2GHz with 266MHz FSB. Namely, these topics will be:

• The performance of Athlon CPUs with 266MHz FSB compared to that of Athlon CPUs with 200MHz FSB.
• The performance gain provided by the new DDR memory: PC1600 and PC2100.
• The competitiveness of AMD Athlon + DDR SDRAM: can such a system beat Pentium 4?

266MHz EV6 Bus

First of all we would like to say a few words about the EV6 processor bus used in AMD Athlon and Duron CPUs and its working frequencies. EV6 bus, which AMD licensed from DEC differs from the GTL+ bus used in Intel Pentium III processors quite significantly. One of the major things that distinguishes EV6 from Intel's GTL+ is the fact that in EV6 all data is transferred along both signal edges, like by DDR SDRAM. So, provided both buses, EV6 and GTL+, work at the same frequency, the data transfer rate offered by the first one is twice as high as that offered by the latter. That's why the processor bus frequency value marked for AMD Athlon and Duron CPUs usually denotes not the strobe signal equal to 100 or 133MHz, but the efficient data transfer rate, which in this case makes 200 or 266MHz. So, later on in this article we will stick to this terminology, especially since it really does reflect the real state of things, because EV6 really does have higher bandwidth than the GTL+.

On 30 October AMD introduced its new Athlon processors supporting 266MHz FSB. Before that all Athlon and Duron CPUs were available only with 200MHz FSB. There is nothing to be surprised at from the technological viewpoint. Last year, when AMD was manufacturing its first Athlon processors, the company promised to increase the EV6 bus frequency up to 400MHz one day. However, why did they raise the bus frequency up to 266MHz only now? The answer to this question is very simple. The thing is that the bandwidth of a 200MHz bus, 1.6GB/sec, was quite enough for all the system components. With a bandwidth of 1.064GB/sec, PC133 SDRAM used in Athlon based systems couldn't load the processor bus to the full extent. That's why speeding up the processor bus didn't make much sense and couldn't ensure any further performance gain.

Now the situation is totally different. The CPUs with 266MHz FSB appeared together with new AMD-760 and ALi MAGiK 1 chipsets supporting DDR SDRAM, which can boast double data transfer rate. So, now increasing the processor bus working frequency can really have a certain effect, because faster processor bus eliminates the possible bottleneck of the system caused by the fact that the bandwidth of the 200MHz EV6 bus is lower than that of the PC2100 DDR memory. As a result, in all new systems built on new AMD CPUs and using PC2100 DDR SDRAM the bandwidth of the memory and processor buses equals to 2.1GB/sec.

By the way, Intel seems to be acting the same way: they also simultaneously increase the processor bus and the memory bus bandwidths. Take, for instance, i850 chipset supporting new Intel Pentium 4 CPU. Its bus works at 400MHz and supports two Rambus channels. That's why both: Quad Pumped Bus and memory bus in Pentium 4 based systems feature similar bandwidth of 3.2GB/sec.

As for Athlon based systems built on AMD-760 and ALi MAGiK 1 chipsets and equipped with PC1600 DDR SDRAM, they will have the CPU working only at 200MHz FSB. The thing is that it is a bit too complicated to make the DDR chipsets work with asynchronous buses, and the strobe signal frequency by PC1600 is 200MHz only.

However, it is not only the happy owners of expensive systems equipped with PC2100 DDR memory, who are lucky enough to be able to use new AMD Athlon CPUs with 266MHz FSB frequency. VIA has also launched a new version of its KT133 chipset: KT133A, which will allow using new Athlon processors in the systems with PC133 SDRAM. However, you should bear in mind that this combination will hardly provide any noticeable performance gain, because the performance of KT133A based systems will be significantly limited by the memory bus bandwidth.

Summing up everything we have just said, we would like to offer you a brief table describing all the today's chipsets supporting new AMD Athlon CPUs with 266MHz FSB:

So, if all new AMD Athlon processors manufactured next year feature 266MHz FSB, there shouldn't be any problems with assembling platforms for them. There are already quite many chipsets supporting new front side bus in all price groups, so that you undoubtedly will be able to find one for yourself.

As far as further EV6 frequency increase is concerned, it is very likely to be worth doing next year already. At least in the end of 2001 we expect new PC2600 DDR SDRAM modules to appear in the market. This memory will feature 333MHz strobe frequency and 2.6GB/sec memory bus bandwidth.

New FSB - New CPUs

Now AMD has already announced three Athlon CPUs supporting 266MHz FSB. They are: 1GHz, 1.13GHz and 1.2GHz models with the clock frequency multipliers equal to 7.5x, 8.5x and 9x correspondingly. In fact, the clock multipliers are the only difference between the new and the old Athlon with 200MHz FSB. The clock multipliers by Athlon CPUs are locked, as you know probably. The new processors have smaller multipliers than the old ones. Besides that, there are no architectural or any other differences between the old and the new CPUs.

So, the basic features of a new AMD Athlon CPU with 266MHz FSB look as follows:

• Thunderbird core manufactured with 0.18 micron technology. The die size makes 120sq.mm.
• The supported clock frequencies include: 1GHz, 1.13GHz and 1.2GHz, with the clock multipliers equal to 7.5x, 8.5x and 9x correspondingly.
• 128KB L1 cache (64KB for data and 64KB for instructions) working at the core frequency.
• Exclusive integrated on-die L2 cache with the size of 256KB working at the full processor frequency with 64bit data path.
• EV6 DDR processor bus working at 133MHz (266MHz efficient working frequency).
• PGA form-factor, 462-pin Socket A.
• 1.7V Vcore.

All the CPUs with a 266MHz FSB are manufactured in a fab in Dresden, because all of them have copper elements. Unfortunately, the new CPUs still heat too much: Athlon 1.2GHz dissipates around 59W. That's why you will have to use a very high-quality cooler with a new Athlon processor, before the company shifts to a new Palomino core.

We were lucky to get our hands on one of these new pieces with 266MHz FSB. It was manufactured during the 31st week, which was somewhere in early August, we suppose. This fact made us think that these were not the processors, but the chipsets, designed in such a way that a 266MHz FSB couldn't be used. In other words, the old AMD Athlon and Duron processors used on the new mainboards can be overclocked not only by means of unlocking and increasing the clock multiplier, but also in a much simpler way: by means of increasing the FSB frequency. However, you should also bear in mind that the new processors featuring the new 266MHz FSB won't work in the old mainboards based on VIA KT133 chipset in nominal mode, because the chipset doesn't support the new FSB frequency.

You can distinguish between the old and the new Athlon CPUs by the processor marking. The second line in the marking of the Socket A processor looks like this:

You should read it as follows:

• The first letter denotes the CPU type. "A" stands for Athlon, "D" - for Duron.
• Then goes the CPU clock frequency.
• The next letter "A" denotes PGA-packaging.
• The next symbol stands for the CPU Vcore: "M" stands for 1.75V, "P" - for 1.7V.
• After that you can see the maximum die temperature: "S" means 95C, "T" - 90C.
• The one but last number is the L2 cache size. "3" stands for a 256KB L2 cache, "2"- for 128KB L2 cache.
• The very last letter is exactly the one to denote the FSB frequency. The CPUs supporting 266MHz bus are marked with letter "C", while the CPUs intended for 200MHz bus - with letter "B".

The photos below show two AMD Athlon CPUs with different clock frequencies: 200MHz and 266MHz:

AMD Athlon 1GHz (200MHz FSB)		AMD Athlon 1GHz (266MHz FSB)

Besides, the CPUs with a 266MHz FSB are also more expensive than their 200MHz fellows.

Testing Environment

To test the new CPUs with a 266MHz FSB we used Iwill KA266-R mainboard based on ALi MAGiK 1 chipset. This mainboard proved very reliable and fast in out DDR Investigation, when we checked its performance with the PC1600 DDR SDRAM. Now it's high time we took a look at its performance with faster PC2100 memory. For a better comparison we also took the results obtained on a system with PC133 SDRAM and a mainboard based on VIA KT133. We also took the results for the today's eldest Intel Pentium CPUs, namely, Intel Pentium III 1GHz and Intel Pentium 4 1.5GHz. So, all in all, there were the following systems tested:

We installed Microsoft Windows 98 SE on all the systems.

Performance

As usual, we first of all suggest looking at the results obtained in a synthetic benchmark called SiSoft Sandra 2001. Of course, we would like to draw your attention to those tests, which take the memory bandwidth in the first place:

The first thing that catches your eye is definitely the huge gap between Pentium 4 and all other testing participants. Please, don't be shocked. SiSoft Sandra 2001 is a synthetic benchmark, which shows only the memory bus bandwidth and how rapidly ALU and FPU instructions are executed. These instructions are responsible for transferring the data to the memory subsystem for further processing. You know that Pentium 4 systems work with dual-channel Rambus memory with the bandwidth of 3.2GB/sec, which is even higher than the bandwidth of the new PC2100 DDR SDRAM. Besides, Pentium 4 ALU works at twice the CPU frequency. That's why these results the benchmarks showed are hardly surprising.

In fact, we are much more interested in the results shown by different AMD Athlon systems, because they differ only by their memory bus and processor bus bandwidths. As you can see from the charts, in case of ALU memory operations PC1600 DDR SDRAM provides about 17% performance increase compared to the results obtained for PC133 SDRAM, while PC2100 DDR SDRAM offers even higher results: 33%. If the data is transferred with the FPU involved, SiSoft Sandra 2001 shows even higher performance increase: 34% for PC1600 DDR SDRAM and 58% for PC2100 DDR SDRAM.

This is the first time we used a new Business Winstone 2001 benchmark in our tests. This test measures the time needed to run some popular office applications, including: Microsoft Office 2000, Lotus Notes R5 mail client, Netscape Communicator 4.7 internet browser, archiving and antivirus utilities. Trying to model the real environment, Business Winstone 2001 runs several applications simultaneously and shifts between them from time to time.

The results of this test show just perfectly that the use of DDR memory in office applications almost doesn't tell on the performance: the gain we see is negligible. Since the applications of this kind do not operate large data packs, PC2100 DDR SDRAM can increase the performance by only 3.5%. As far as Pentium 4 is concerned, it looks even worse than AMD Athlon 1.2GHz working with PC133 SDRAM, not to mention the DDR systems. All in all, AMD Athlon 1.2GHz with PC2100 DDR SDRAM manages to prove 8% faster than the notorious Pentium 4 1.5GHz.

Also we replaced the traditional Content Creation Winstone 2000 with a new version called Content Creation Winstone 2001. This benchmark works just like the previous version and differs only by the set of applications used. This benchmark version uses newer versions of the following content creation apps: Adobe Photoshop, Adobe Premiere, Macromedia Director, Macromedia Dreamweaver and Sonic Foundry Sound Forge.

Since faster data access is much more important for content creation applications, DDR SDRAM appears more efficient and provides higher performance gain. In case of a system equipped with PC1600 DDR SDRAM we get a 7% performance gain, while in case of PC2100 DDR memory it makes 13%. Again AMD Athlon 1.2GHz beats Intel Pentium 4 1.5GHz by nearly 10%, which is quite tangible.

SYSmark 2000 is another benchmark measuring the CPU performance in office and content creation applications. However, the performance of the CPU is taken for each applications separately that's why the benchmark doesn't load the memory that much (compared with the previously described tests). It is especially noticeable in Office Productivity applications.

The performance gain in case of PC1600 DDR SDRAM is hardly noticeable and PC2100 DDR SDRAM provides an only a 4% growth. However, despite this fact the system with Intel Pentium 4 1.5GHz falls behind the system built with AMD Athlon 1.2GHz by over 15%.

To estimate the system performance in a popular 3D modeling application 3D Studio MAX, we checked the time each system required to render Anisotropic Wheel scene at 800x600. So, take note that the smaller is the value (the less time the system needed), the better. Since in 3D Studio MAX the major workload falls upon the processor FPU and not upon the memory bus, we see absolutely identical results in all systems with AMD Athlon processors working at the same frequency. This is also the reason why Pentium 4 proved very poor here: it executes the standard floating point operation slower than AMD Athlon. Therefore, AMD Athlon 1.2GHz combined with PC2100 DDR memory shows 35% higher performance than Intel Pentium 4 1.5GHz. However, you should keep in mind that in case the applications had been optimized for SSE2 set, which includes some floating point instructions as well, Pentium 4 could have performed much faster. And in fact, it will perform faster because we expect this optimization to turn up quite soon already.

In order to find out how fast the CPUs appear when compressing data, we measured the time each system required to compress a 100MB directory with the texture-files for Unreal Tournament. In this case the use of PC2100 DDR SDRAM ensured 18% performance increase compared to the results obtained for PC133 SDRAM. While Pentium 4 1.5GHz fell behind the eldest Athlon CPU by over 27%.

We also took a look at mp3-files encoding speed with the help of a well-known AudioCatalyst application. For this purpose we used a specially created 100MB wav-file. And again the system with Athlon 1.2GHz CPU and PC2100 DDR SDRAM proved the best. It turned out capable of encoding mp3-files 8% faster than the similar system with PC133 SDRAM and 50% faster than the system built with Intel Pentium 4 1.5GHz. As far as PC1600 DDR memory is concerned, the test shows very clearly that there is hardly any need to replace your PC133 with PC1600 SDRAM: they are very close.

And now let's shift to gaming applications. Trying to satisfy all our readers, we carried out a lot of gaming tests of all sorts. However, before we pass over to the actual gaming, we suggest taking a quick look at the synthetic 3DMark2000 benchmark.

As you can see from the results obtained in this benchmark, DDR SDRAM can ensure a really tangible performance gain even in those applications, which mostly load the graphics subsystem. For instance, with the resolution set to 800x600 in 16bit color mode PC1600 DDR SDRAM provides a 2% increase in performance, while the use of PC2100 DDR SDRAM - a 10% increase compared to what we can squeeze out of the system with PC133 SDRAM installed. As for the results obtained for Pentium 4 1.5GHz, it appears very hard to beat in 3DMark 2000. Only AMD Athlon 1.2GHz combined with PC2100 DDR memory proves just a bit faster than Pentium 4 1.5GHz.

At the resolution set to 1024x768x32 Pentium 4 1.5GHz appears invincible, because the higher gets the resolution, the larger appear the data packs transferred that's why the bus bandwidth turns out one of the most important things.

The results obtained in Quake3 show that increasing the memory bus bandwidth doesn't make any sense if the processor bus bandwidth remains unchanged. As you can see from the diagram, the performance increases greatly only in case Athlon gets a new 266MHz FSB and PC2100 DDR memory. It gets 13% higher! In case of a Pentium 4 system, it is even more impressive: Pentium 4 leaves Athlon by over 25% behind!

With the growth of the resolution, the processor gaming performance gets limited by the AGP bus bandwidth as well as by the graphics card used in the system. That's why all the systems proved very close to one another here. Nevertheless, PC2100 DDR SDRAM still managed to beat PC133 SDRAM by 5%.

We have also included Quake3: Team Arena demo-version in our tests. This game is also built on Quake3 engine, however, its geometry is much more complicated and the textures are larger. Nevertheless, the outcome is very similar to what we observed in regular Quake3. The real performance gain in Athlon systems made about 12% due to the use of PC2100 DDR SDRAM, and Pentium 4 1.5GHz again surpassed the eldest Athlon CPU by 25%.

The results here resemble those of the ordinary Quake3 Arena. It's only the absolute values that differ.

The situation in Unreal Tournament looks the same as in Quake3: PC1600 DDR SDRAM doesn't have any tangible effect. However, PC2100 DDR SDRAM in Athlon systems provides an 8% growth in performance. As for the Pentium 4 1.5GHz and Athlon 1.2GHz competition, both showed almost the same amount of fps.

MDK2 is a typical gaming application of the older generation, because this game uses a relatively small amount of polygons. Nevertheless, the results obtained in MDK2 are very close to the picture we saw in Quake3. PC1600 DDR SDRAM again remains nearly useless. In the system built with AMD Athlon CPUs and PC2100 DDR SDRAM the performance increases by 8%. And Pentium 4 1.5GHz again leaves AMD Athlon 1.2GHz with DDR memory 7% behind.

In higher resolutions the gaps between the competitors get smaller.

The last gaming application, which we decided to use in our review, was Mercedes-Benz Truck Racing demo version. This truck racing simulator is a good example of the latest generation games, which use a lot of textures and complex geometric model.

Since the game requires a lot of data to be transferred through the memory, unlike all the previous tests, even PC1600 DDR SDRAM appears worth using here: it offers a 3% performance increase compared to the system with PC133 SDRAM. However, the results prove much cooler as soon as we shift to a 266MHz FSB and PC2100 DDR memory. Here the gain over the system with PC133 makes about 20%.

However, even this advantage doesn't make AMD Athlon 1.2GHz fast enough to beat Intel Pentium 4 1.5GHz, which again turns out 8% ahead. These results give us to understand one more time how important the memory bus bandwidth is for gaming applications.

Conclusion

Well, let's sum up what we've got. According to the tests we have carried out, PC2100 DDR SDRAM used with AMD Athlon CPUs may provide about 10% performance gain. This value may vary depending on the application type. In office apps, the performance gain is hardly that noticeable, while in games, especially in the latest ones with complicated geometry and large textures, the effect made by the DDR memory is much greater.

However, faster memory is not the only thing you need to speed up the system. In order to really use the DDR memory to the full extent, you'd better get new CPUs with 266MHz FSB. Otherwise, narrow processor bus may turn out a bottleneck of your system and will limit its performance. This is exactly the reason why the systems with PC1600 DDR SDRAM and the CPUs featuring 200MHz FSB prove as fast as the systems with PC133 SDRAM, not more.

Speaking about Intel Pentium 4, we should point out that it proved a really great CPU for gaming needs. Even the new Athlon with a 266MHz FSB working together with DDR memory appeared unable to beat it. Sometimes the gap in performance increased up to 25%! But as it came to office applications, Pentium 4 immediately lost the lead. In business, content creation, 3D modeling and mp3 encoding applications Athlon managed to leave its competitor far behind.

So, taking into account that Athlon based systems are cheaper than those with Intel Pentium 4 inside, a combination of AMD Athlon + DDR memory is undoubtedly the best choice you could make today. Unless Pentium 4 starts supporting DDR memory, which is cheaper than the currently used RDRAM (should happen somewhere in 2002 at the earliest), and the cost of the systems with it also gets down to some acceptable level, Athlon will remain the best choice for those who want to have high performance systems for a reasonable price.

However, extreme gamers who are ready to pay any crazy sum of money for higher fps rates, will most likely decide on a Pentium 4. Especially since its performance is expected to grow even more as soon as SSE2 instructions find wider application.

Therefore, next year AMD will have to do its best to catch up with Pentium 4 in terms of clock frequencies and to find a way to improve the gaming performance of its processors. Otherwise, the situation in the CPU market will return to what we all saw about 1.5 years ago, when AMD was considered to be a CPU manufacturer of the Value sector.