Two Cores at a Low Cost: AMD Athlon 64 X2 3600+ CPU Review

Having lost the leadership in the high-end market segment, AMD started conquering the low-end territory. Today we would like to take a closer look at the new Athlon 64 X2 3600+ that boasts the lowest price point of all the dual-core AMD solutions available in the market.

by Ilya Gavrichenkov
08/11/2006 | 10:34 PM

The launch of Intel Core 2 Duo processors provoked significant changes in the processor market. In response to Intel’s launch AMD dropped the prices of its dual-core processors and hence had to completely reposition the entire dual-core processor line-up. The Athlon 64 X2 CPUs that have become considerably less expensive turned into mainstream solutions, which allows AMD to maintain the processor sales on the same level as throughout the past few years.

 

However, we shouldn’t forget that Core 2 Duo and Athlon 64 X2 are far not the only dual-core processor families existing in the today’s market. Besides them, there are also Intel Pentium D 9XX and Pentium D 8XX CPUs on NetBurst architecture, that haven’t yet been dumped into oblivion. The arrival of Core 2 Duo forced the prices of these processors to go down, so that they rapidly turned into budget dual-core solutions.

In other words, the dual-core Athlon 64 X2 processors acquired new competitors that perform faster and sell at a lower price. In this situation it is pretty hard for AMD to attract new customers. So, it is quite logical that they decided to make the following move. Since they couldn’t really add any new dual-core processor models to the “top” of the processor line-up, because of highly competitive Intel Core based solutions, they decided to expand their product range from the “bottom” by introducing new low-cost solutions that could compete with the Intel Pentium D processors.

Today we would like to introduce to you a new Athlon 64 X2 3600+ processor that was released to serve this particular purpose. This processor is not yet included into the company price-list, however we tend to believe that it should sell at about $130-$140, which is $15-$20 less than the price of Athlon 64 X2 3800+. As a result the newcomer will become direct competitor to Pentium D 915. Although this processor is based on the old Presler core with NetBurst microarchitecture, it boasts very attractive price-to-performance ratio after the last price drop.

Closer Look

We managed to get the AMD Athlon 64 X2 3600+ processor from one of the retail stores, although, unfortunately, it was slightly overpriced and was selling for $150. However, this is still a total newcomer at this time, so the retailers are trying to benefit a bit more from selling this “fresh and exclusive” new product. Hopefully, the prices will go down soon, since from the formal prospective this Athlon 64 X2 3600+ is seriously behind Athlon 64 X2 3800+ selling for $152: although they both work at the same clock speed of 2.0GHz, Athlon 64 X2 3600+ features half the L2 cache per core: 256KB.

At first glance this CPU reveals a lot of interesting details about itself:

Take a closer look at the marking. ADO3600IAA4CU line indicates that this processor belongs to energy efficient type. The typical heat dissipation of Athlon 64 X2 3600+ is 65W. In fact, there is nothing strange about it: It is fairly easy for the manufacturer to reduce the Vcore of the youngest processor in the family to 1.2V-1.25V. However, this small effort pays well: the CPU immediately falls into the unannounced energy efficient category offering attractive performance-per-watt that has become very common criterion since the launch of Intel Core 2 Duo. Moreover, since AMD is selling its Energy Efficient processors at a slightly higher price than the regular CPUs, Athlon 64 X2 3600+ becomes a very attractive offering, especially against the background of 65W Athlon 64 X2 3800+ officially selling for $176.

Also the processor marking indicates that the total L2 cache size is 512KB. In other words, Athlon 64 X2 3600+ is the first and so far the only AMD CPU featuring 256KB of L2 cache per core. From this prospective, it could have been also called Sempron X2, at least there are single-core Sempron processors with 256KB L2 cache in AMD’s product line-up. However, AMD is going to officially introduce dual-core Sempron processors only when they switch to 65nm mass production in 2007. Therefore, in the meanwhile the new processor that turns out very similar to the dual-core Sempron will be selling under the “Athlon 64 X2” brand name.

The diagnostic CPU-Z utility recognizes the Athlon 64 X2 3600+ quite correctly:

The screenshot doesn’t hide any surprises. The processor clock frequency is really 2.0GHz, and the cache memory is half as big as that of Athlon 64 X2 3800+. The L2 cache is designed exactly as by any other AMD processor. And it means that AMD may be building Athlon 64 X2 3600+ on the same semiconductor dies that they use for the “fully-fledged” Athlon 64 X2 by simply disabling half of their cache. In other words, the launch of Athlon 64 X2 3600+ allows AMD to put to good use some of the dies with partially non-operational cache memory.

You can actually see from the screenshot that Athlon 64 X2 3600+ uses the same die as any other dual-core Socket AM2 processor: the processor we had at our disposal is based on the traditional Windsor revision F2 core. Of course, the use of the same dies for Athlon 64 X2 3800+ and 3600+ allows AMD to reduce the production costs and hence to offer more attractive retail prices. As a result, AMD should be able to drop the prices down to the desired $100 mark for its youngest Athlon 64 X2 processors by the end of the year.

Here I would only like to add that Athlon 64 X2 3600+ processor is assigned to the Athlon 64 X2 family, and not Sempron, because it supports DDR2-800 SDRAM, which is currently the prerogative of AMD’s top processor family.

Summing up everything I have just said, let me offer you a list of formal specifications of the new Athlon 64 X2 3600+ processor that are still absent even on AMD’s official web-site:

Athlon 64 X2 3600+

Marking

ADO3600IAA4CU

Frequency

2.0 GHz

Packaging

Socket AM2

L2 cache

2 x 256 KB

Memory controller

128-bit, dual-channel

Supported memory types

DDR2-533/667/800 SDRAM

Hypertransport bus frequency

1 GHz

Core stepping

F2

Production process

90 nm, SOI

Transistors

153.8 mln.

Die size

183 sq.mm

Typical heat dissipation

65 W

Maximum case temperature

72o C

Vcore

1.20 - 1.25 V

AMD64 technology

Yes

NX-bit

Yes

Cool’n’Quiet technology

Yes

Overclocking

As we have already pointed out in our previous article called “AMD’s Response to Intel Conroe: Energy Efficient Athlon 64 X2 CPU”, AMD Energy Efficient processors do not always boast satisfactory overclocking potential. Athlon 64 X2 3600+ is one of those processors, so we decided not to pin too many hopes upon its overclocking potential.

The practical experiments were conducted on a traditional testbed including the following hardware components: ASUS M2N32-SLI Deluxe mainboard based on Nvidia nForce 590 SLI chipset, Corsair Twin2X2048-8500C5 memory and PowerColor X1900 XTX 512MB graphics card. The processor was cooled with Zalman CNPS9500 AM2 air-cooler. Since the maximum clock frequency multiplier of the

Athlon 64 X2 3600+ is locked at 10x maximum, these CPUs can only be overclocked by raising the clock generator frequency. In this case we had to reduce the multiplier for the memory frequency and HyperTransport bus connecting the CPU with the SPP in order to ensure that all other subsystems of the test platform work stably.

We worked to reveal the maximum clock speed this processor could work at by raising the Vcore from the nominal 1.25V to 1.5V. Note that this Vcore increase is not really dangerous for the CPU, because they build Athlon 64 X2 3600+ using the same semiconductor dies as in the “normal” dual-core processors with the nominal core voltage of 1.3-1.35V.

In this case we managed to retain system stability not only in general benchmarking applications but also in the special tests (such as S&M, in the first place) with the clock generator frequency at 260MHz. Further frequency increase affected the system operational stability, although it would still boot at up to 275MHz frequency.

So, we would consider 2.6GHz clock speed the final result of our Athlon 64 X2 3600+ overclocking experiment.

As a result, our Athlon 64 X2 3600+ sample overclocked by 30%, i.e. up to the level of Athlon 64 X2 5000+. Note that this overclocking can be quite efficient from the performance prospective, because the clock generator frequency of 260MHz also allows overclocking the memory. Even the minimal memory frequency divider (CPU Frequency / 5) that ensures DDr2-800 SDRAM support in the nominal mode allowed increasing the memory frequency to 1040MHz.

There are a lot of overclocking-friendly memory modules in the market these days. Take, for instance, Corsair Twin2X2048-8500C5. Although, unfortunately, we had to set the maximum timings and 2T Command Rate, the performance turned out better than in case of DDR2-800 SDRAM with 4-4-4- timings and 1T Command Rate.

So, you can expect the overclocked to 2.6GHz Athlon 64 X2 3600+ to reach the performance level of the top AMD Athlon 64 X2 processors. And now we are going to perform a few additional tests to prove this statement.

Testbed and Methods

The major goal of our test session was to find out the performance potential of the new AMD Athlon 64 X2 3600+ processor. In this case it was interesting to compare it against AMD Athlon 64 X2 3800+ working at the same clock speed, but featuring twice as large L2 cache and against Intel Pentium D 915, which is its main competitor in the same price group.

As for the overclocked to 2.6GHz Athlon 64 X2 3600+, we decided to compare it against 2.6GHz Athlon 64 X2 5000+.

For a more illustrative picture, besides the processors mentioned above, we will also offer you the benchmark results for Intel Core 2 Duo E6300 processor, which is actually not a direct rival to our today’s hero.

So, this is what we used to build our test platforms:

The tests were performed with the mainboards BIOS setup for maximum performance.

When we overclocked Athlon 64 X2 3600+ to 2.6GHz, the memory worked in DDR2-1040 mode with the timings set to 5-5-5-15-2T.

Performance

SYSMark 2004 SE: General Performance

The first results reveal relatively small performance difference between Athlon 64 X2 3600+ and Athlon 64 X2 3800+. According to SYSMark 2004 SE, it is no more than 5%. So, we can conclude that the half as big cache memory of the new dual-core Athlon 64 X2 processors of only 256KB leads to no dramatic results.

I would also like to stress that the performance of the new AMD CPU looks very good against the background of the Pentium D 915 processor. Athlon 64 X2 3600+ allows AMD to claim that they are offering the best price-to-performance ratio in the budget segment.

Synthetic Benchmarks

Old single-threaded benchmarks demonstrate almost the same performance level for both; Athlon 64 X2 3600+ and 3800+: the performance difference doesn’t exceed 2%. Moreover, Athlon 64 X2 3600+ also performs quite well when overclocked: it outpaces Athlon 64 X2 5000+ working at the same clock frequency and featuring twice bigger L2 cache. Of course, it is fast memory that contributed mostly to this victory. Thanks to increased clock generator frequency, the memory is running at over 1GHz speed.

Although the size of cache memory doesn’t seriously affect 3DMark06 results, the situation between Athlon 64 X2 5000+ and Athlon 64 X2 3600+ overclocked to 2.6GHz changes to the opposite. As for the performance of our hero in the nominal mode, we have to admit that it is again much faster than the Intel competitor with the same price – Pentium D processor.

ScienceMark 2.0 is also almost completely indifferent to the size of L2 cache of the dual-core processors. So, the only remarkable thing worth mentioning is certainly the high performance of the K8 based processors.

Gaming Applications

As we know from the previous tests, the gaming applications are quite sensitive to the size of single-core processor cache memory. In case of dual-core CPUs, this rule remains active. So, Athlon 64 X2 3600+ is on average 3%-5% behind Athlon 64 X2 3800+ in games. However, this performance difference is very unlikely to scare away potential AMD Athlon 64 X2 buyers.

Audio and Video Encoding

We can hardly draw any conclusions from the video encoding performance charts. The performance of Athlon 64 X2 3600+ processor is quite close to that of the next model in the family, which is 3800+. As for its advantage over the Intel Pentium D 915 competitor, the gap is pretty significant.

Image and Video Editing

The same situation can be observed in image processing and non-linear video editing applications. Even the overclocked Athlon 64 X2 3600+ working at 2.6GHz performs pretty traditionally. We can conclude that fast memory makes up for its smaller L2 cache, so when we overclock the processor to 2.6Ghz, it catches up with Athlon 64 X2 5000+.

Archiving Applications

WinRAR is probably one of the few tests that benefits evidently from a larger cache, because this application is very critical about the memory subsystem performance. However, the performance difference between the two CPUs working at the same clock speed, but featuring very different L2 caches of 512KB and 1024KB, is not as dramatic as you may have expected: 4.7%.

Professional OpenGL and Final Rendering

The results obtained in typical professional tasks are far from being original. Cache memory size doesn’t really affect the final rendering speed. As for OpenGL, you can notice the performance difference in one test out of four.

Conclusion

The obtained results indicate that the new low-cost AMD processor that has already started selling turned out a very attractive solution. Although Athlon 64 X2 3600+ features half the L2 cache compared with the “fully-fledged” dual-core Athlon 64 X2 CPUs and hence can be regarded as a “dual-core Sempron” at some point, its performance didn’t suffer that much. In the worst case, Athlon 64 X2 3600+ is no more than 5% behind the 3800+ model with the same nominal clock speed of 2GHz. And in fact, there are very few applications like that. In other words, Athlon 64 X2 3600+ offers very decent performance, especially keeping in mind that it is less expensive than the 3800+ model.

If we compare the performance of our hero against Intel Pentium D 915, which will most likely be its primary competitor from the pricing standpoint, the AMD solution turns out a definite winner. Just like before, the new AMD processor on K8 microarchitecture outperforms the competitor built on NetBurst. Even the recent price wars didn’t change anything, and the recently announced Core 2 Duo processors are still in a different price category.

The important advantage of Athlon 64 X2 3600+ is that it belongs to the Energy Efficient type with the 65W maximum heat dissipation. As a result, this solution will become very popular in quiet systems, because Energy Efficient dual-core AMD processors have always been a little bit more expensive.

As for overclocking, we managed to hit only 2.6GHz clock speed, which is not too impressive. However, on the other hand, the performance boost from overclocking appeared quite tangible. Athlon 64 X2 3600+ working at 2.6GHz can compete successfully with the top model in the family with 5000+ performance rating. So, those overclocking fans who decide to go with the new AMD CPU will be happy.