by Ilya Gavrichenkov
05/27/2005 | 10:44 AM
The launch of dual-core AMD Athlon 64 X2 and Intel Pentium D/Intel Pentium Extreme Edition processors gave way to endless debates on numerous web-sites and hardware forums. Although these CPUs are not available in retail yet, the violent discussions of the performance highs and lows of the new dual-core AMD and Intel processors keep going on. Actually, it is evident already that AMD dual-core architecture turned out more successful from the performance point of view.
Due to the fact that the top AMD Athlon 64 X2 processors work at the same core clock frequency as the top Athlon 64 CPUs, they prove quite efficient even in single-threaded environments. And in multi-threaded applications they are simply beyond any competition. The competitor from Intel, the Pentium Extreme Edition working at 3.2GHz core clock yields to AMD Athlon 64 X2 in both cases.
It looks like this verdict should have wound up the competition matter between dual-core processor solutions from different manufacturers. However, in our comparison of the top processor models in both dual-core families from Intel and AMD we didn’t take into account one more very important factor: the price.
Actually, you can notice a few pretty interesting things when you compare the price of AMD Athlon 64 X2 processors with that of the youngest Pentium D models:
CPU | Price | CPU | Price |
Athlon 64 X2 4800+ | $1001 | Pentium Extreme Edition 840 | $999 |
Athlon 64 X2 4600+ | $803 |
| |
Athlon 64 X2 4400+ | $581 | ||
Athlon 64 X2 4200+ | $537 | Pentium D 840 | $530 |
| Pentium D 830 | $316 | |
Pentium D 820 | $241 | ||
As we see, AMD and Intel position their dual-core processor absolutely differently, so that the direct side by side comparison is only fair for the top models of the processor families. AMD Athlon 64 X2 processors extend the single-core Athlon 64 processor family from the top. In other words, dual-core processors from AMD occupy the niche above the single-core ones (we do not take into consideration the exclusive Athlon 64 FX here). Intel, on the contrary, “dilutes” the single-core processor line-up with the dual-core ones. It means that today Intel is offering users the choice between single-core and dual-core solutions. They are offered at about the same price. Therefore, although Athlon 64 X2 processors are very attractive, they are still targeted for pretty wealthy users. Those guys who work in multi-threaded applications a lot but do not want to spend tons of money on the new processors are most likely to go for Pentium D. No other way.
These particular suppositions pushed us to return to dual-core processors discussion again and to take a closer look at the performance of the youngest Pentium D CPU models relative to the solutions offered at the same price point. So, today we would like to particularly dwell on the features and performance of the new Pentium D 820 processor compared against its direct competitors: Pentium 4 and Athlon 64 offered in the same price range.
Note that in our today’s article we will not speak about the peculiarities of the dual-core architectures from AMD and Intel. If you want to learn more about them you can always check our previous articles called:
Pentium D 820 processor is the youngest dual-core CPU from Intel based on the Smithfield core. This CPU is none other but a combination of two Prescott dies within a single piece of silicon.
It works at 2.8GHz clock frequency and has no Hyper-Threading Technology support. The detailed formal characteristics of this solution are given in the table below:
Pentium D 820 | |
Frequency | 2.80 GHz |
Package | 775-pin PLGA |
Vcore | 1.25V-1.4V |
Bus frequency | 800 MHz |
Typical heat dissipation | 95W |
Core stepping | A0 |
Max. typical case temperature | 69.8°C |
L2 cache size | 1MB+1MB |
Production technology | 90 nm |
Hyper-Threading Technology support | No |
Intel Extended Memory 64 Technology (EM64T) support | Yes |
Execute Disable Bit Feature (NX) support | Yes |
Enhanced Intel SpeedStep (EIST) support | No |
I would like to draw your attention right away to a few curious things that you can see in the specification.
Firstly, Pentium D 820 processor does not support Intel Enhanced SpeedStep technology, which is available in all other dual-core processors on Smithfield core. The reason for this is the clock frequency multiplier, which equals 14x for this CPU. It is the minimum clock frequency multiplier for all processors based on modifications of Prescott core. For the same reason, Pentium D 820 does not support such technologies as C1E (Enhanced Halt State) Technology and TM2 (Thermal Monitor 2) Technology, which also require dynamic change of the CPU clock frequency multiplier.
Secondly, the low TDP level of the Pentium D 820 processor is also quite remarkable here. All other Pentium D CPUs and Pentium Extreme Edition 840 feature the thermal design power of 130W. Moreover, this characteristic of the Pentium D 820 processor is even lower than that of the top single-core Pentium 4 solutions: their TDP equals 115W. This gives us some hope that Pentium D 820 will turn out not so hot as the previously reviewed Pentium Extreme Edition 840 and will allow using pretty simply cooling solutions. Besides, relatively low heat dissipation and power consumption of the Pentium D 820 processor should make it possible for this processor to work just fine in mainboards without “enforced” CPU voltage regulator.
Other than that, Pentium D 820 doesn’t boast anything else different from its elder brothers.
CPU-Z utility provided the following info about this processor:
The operating system sees this CPU as two processors, which is actually not surprising at all, because it has two physical cores and doesn’t support “virtual multi-core architecture", i.e. the Hyper-Threading Technology.
We couldn’t disregard testing the power consumption of the Pentium D 820 processor, of course. It was the low TDP Intel set for this processor that stimulated our interest to this parameter. If the power consumption (and, consequently, the heat dissipation) of this CPU is not that high, it will be even more attractive for the users.
The diagrams below show the results of power consumption measurements for the Pentium D 820, Pentium 4 and Athlon 64 CPUs offered at the same price point today. We used the special S&M utility to load the CPUs to their maximum for a more illustrative picture. You can download this utility here.
Since Pentium 4 processors participating in this test support C1E technology, their working frequency drops down to 2.8GHz in idle mode. That is why the dual-core Pentium D 820 processor working at the same frequency under any workload consumes a little bit more power than its single-core fellows. However, the power consumption of the Pentium D 820 processor in idle mode is just a little bit higher than that of the Pentium 4.
As for Athlon 64, it is a few times less power-hungry here. And the remarkable thing is that we tested it with Cool’n’Quiet disabled!
Even under the maximum workload Athlon 64 CPUs (we tested those on Venice core) also boast considerably lower power consumption. You may consider it funny but the Athlon 64 processors under maximum workload consume about the same amount of power as the Pentium 4 processors in idle mode. This is something to think about, don’t you agree?
As for the power consumption of our today’s hero, Pentium D 820, it eats up about the same amount of power as the Pentium 4 processors from the same price group working at 3.0-3.4GHz. By the way, these processors’ TDP is set at 84W, so it looks like Intel set the 95W barrier for its Pentium D 820 just in case.
During our tests of the Pentium D 820 processor we revealed a few unexpected issues with the mainboards compatibility.
First of all, I would like to remind you that Pentium D processors require special chipsets, which should not only work with dual-processor configurations, but also be optimized for dual-core processors. If you install a Pentium D processor into a board based on an older chipset, it will simply not start. Luckily, you will not harm the CPU or the mainboard in this case.
The list of chipsets supporting Pentium D CPUs has been revealed for a quite a while now. It includes the new Intel 955X and Intel 945P/G, and NVIDIA nForce4 SLI (Intel Edition). The previous generation chipsets, i925/i915, do not support dual-core processors. However, our tests showed that the situation with Pentium D 820 is somewhat different.
Pentium D 820 doesn’t have any problems working in i955X or i945P/G based mainboards. In fact, this is quite normal, even despite the fact that i945P/G based mainboards do not support the dual-core Pentium Extreme Edition 840. In fact, I assume this is a purely marketing limitation.
The situation with Pentium D 820 and NVIDIA nForce4 SLI (Intel Edition) is much worse. Our tests revealed a few compatibility issues in this combination. When we installed our Pentium D 820 into NVIDIA nForce4 SLI (Intel Edition) based mainboards (and we tested a few most popular models), the system worked pretty strangely. Although the mainboard detects two processor cores and the operating system boots-up successfully, many popular applications either freeze or cause the platform restart. If you disable the second core in the BIOS Setup the problem will go away, but I don’t think you will like the idea of using a dual-core CPU in single-core mode.
NVIDIA’s comments did not shed any light on the issue (for details see this news story). The company representatives we asked about this matter did confirm that Pentium D 820 is incompatible with NVIDIA nForce4 SLIU (Intel Edition), and advised to use faster dual-core solutions, because the chipset was initially developed for computer enthusiasts who do not work with slow CPU models.
So, Pentium D 820 is only compatible with the new Intel chipsets: i955X and i945P/G. By the way, we haven’t yet reviewed the mainstream i945P/G chipsets announced last week, that is why for your reference I would like to offer you a table with the main characteristics of these chipsets compared against other Intel sets of core logic:
Click to enlarge
We haven’t yet undertaken any overclocking experiments for dual-core CPUs. Nevertheless, we couldn’t leave out this exciting aspect, because there will definitely be enthusiasts among you who would wish to squeeze even more speed from their dual-core processors. Especially, the youngest processor model of the Pentium D family is simply calling for an overclocker: it just has to overclock at least up to the level of the top processor in this product line, which works at 3.2GHz. Moreover, keeping in mind that Smithfield is a combination of two Prescott cores of E0 stepping on a single semiconductor die, we can expect even more fruitful overclocking: the latest CPUs based on Prescott and Prescott-2M core proved easily overclockable beyond 4GHz bar. However, dual-core processors should have more specific and sophisticated overclocking procedures than their single-core fellows. The main problem will inevitably lie with their high heat dissipation. All in all, we couldn’t help carrying out a few practical experiments.
For our Pentium D 820 overclocking experiments we assembled a platform on ASUS i955X based P5WD2 Premium mainboard. The cooling was provided by a pretty efficient Zalman CNPS7700Cu cooler. During overclocking we didn’t increase the processor Vcore. The CPU was overclocked by raising the FSB frequency: the clock multiplier of the Pentium D 820 processor is locked just like by Intel’s single-core solutions. The PCI Express and PCI bus frequencies were fixed at the nominal values. The memory frequency was reduced a little bit so that the Corsair CM2X512A-5400UL memory modules didn’t turn into a bottleneck during overclocking.
The actual overclocking of Pentium D 820 processor started quite unexpectedly. We managed to raise the FSB frequency to 250MHz in no time and without any special effort. This brought the CPU clock rate up to 3.5GHz.
The system started and booted-up normally at this speed and allowed running all sorts of small utilities (including single-threaded ones) without any problems. However, when we took a closer look at the system functioning in these conditions, we saw that it could not provide fully-fledged functionality in this case. The Zalman CNPS7700Cu cooler couldn’t cope with its task when the CPU got loaded heavily.
The temperature kept growing and the CPU would shut down. Since Zalman CNPS7700Cu is a pretty powerful air cooler, the conclusion we can draw here is not very optimistic. You need an extremely efficient cooling solution, a water-cooling system, for instance, if you intend to try overclocking your dual-core processor. We still decided it would be interesting to find out what is the maximum frequency our processor can work at stably with the air cooler, because this type of cooling is currently used in most computer systems. We reduced the FSB frequency to 240MHz and continued out stability tests. The CPU was working at 3360MHz in this case.
The results obtained in this case turned out even more interesting. The thing is that the system remained stable, the CPU temperature stayed within the acceptable range, and all major tests would run smoothly. However, when we started a benchmark supporting multi-threading, some weird things began happening. The results appeared suspiciously low in this case. When we launched two independent copies of a single-threaded application (we used WinRAR archiving utility), we managed to reveal a very interesting effect: Pentium D cores can get into thermal throttling independently. In other words, the first core continued working at its normal speed, while the second core started missing clocks losing its speed tremendously. The strange thing is however, that the temperature still remained within acceptable range of 75-78oC.
It turned out that the explanation is fairly simple. The temperature reported by the CPU is the temperature of the first core only. Unfortunately, Pentium D processors do not allow monitoring the temperature of both cores, this feature is implemented only in dual-core server processors.
So, to our great disappointment we cannot find out what actually happened with the second core. In our case, only the second core got overheated and went to thermal throttling, while the first core kept working normally.
So, we had to drop the FSB frequency to 230MHz and continue our tests. The CPU in this case worked at 3220MHz. At this frequency the second core didn’t get overheated any more, which is actually not a surprise for us, because this frequency is close to the clock rate of the top Pentium D CPU models.
So, our experiments suggest that Pentium D can only be overclocked if you have efficient cooling solution at hand. Regular air coolers allow significantly modest overclocking of this processor up to 3.2-3.3GHz only without thermal throttling of any of the cores.
As we have promised in the beginning of this article, Pentium D 820 will compete in our performance tests against other processors offered at the same price point. Among them are AMD Athlon 64 3200+ and 3500+, Intel Pentium 4 540 and 550 and Pentium 4 630 and 640, which are priced between $200 and $270. This test session will allow us to conclude whether it would be a good idea to base your platform particularly on the Pentium D 820 CPU.
Our platforms were assembled with the following components:
The results of Pentium D 820 tests in signle-threaded office applications are pretty logical: dual-core CPU is slower than its single-core fellows with higher clock frequency.
In the multi-threaded environment created by the same single-threaded applications running in parallel, the situation is different. Depending on how serious the multi-threaded workload actually is, Pentium D 820 starts showing better results, getting far ahead its single-core competitors from AMD and Intel in the last test.
The same is true for SYSmark 2004 tests supporitng multi-threading. Pentium D 820 is not the last one here, but also not the first one. It goes very nicely with the other Cpus from the same price range.
Although Multimedia Content Creation Winstone 2004 test measures the processors performance basing on their speed in typical digital content creation applications, which support multi-threading, Pentium D 820 is not so good here.
However, in SYSmark 2004 tests emulating the user’s work with digital content, Intel’s dual-core CPU is almost always the leader.
PCMark04 benchmark does support multi-threading therefore Pentium D 820 looks very attractive here.
Unfortunately, we can’t say the same about 3Dmark benchmark family, because they do not use the second processor core, just like most contemporary games.
However, 3Dmark05 has two purely processor tests working in two threads: one of them emulates the shaders and another one calculates the physical environment model. In this case Pentium D 820 proves very impressive, yielding to Athlon 64 3500+ only once. Note that none of the Pentium 4 processors from the same price range can compete with Pentium D 820 here.
The situation with gaming applications has long been quite clear. The developers of this software use only single-thread algorithms, that is why dual-core processors cannot provide any benefits in games. And it looks like will not for quite a long time.
Pentium D 820 showed pretty low results in WinRAR, because this archiving utility uses only one core of the dual-core processor. So, relatively low clock frequency of only 2.8GHz prevented it from competing successfully with pentium 4 CPUs working at 3.0-3.4GHz and Athlon 64 processors boasting very efficient low latency memory subsystem.
Another archiving utility, 7zip, does support multi-threading, however, Pentium D 820 still occupied only the last place in it. The real multi-core architecture seems to be of no use here, because the apoplications is optimized for “virtual” multi-core, i.e. Hyper-Threading technology.
During audio and video encoding with different codecs, Pentium D 820 processor demonstrated pretty good results. It proved faster than Athlon 64 processors of the same price in all tests, and in LAME, Windows media Encoder and DivX it also outperformed single-core Pentium 4 CPUs.
Professional Adobe applications for image editing and video editing/processing are well optimized for multi-processor systems. That is why Pentium D 820 performed so well here.
Software developers will not benefit from platforms based on dual-core processors, because major popular compilers do not use multi-threading.
Although we do see some advantages of the dual-core architecture in Sciencemark test, Pentium D 820 manages to outperform only Pentium 4 630, which works at 200MHz higher clock frequency.
Pentium D 820 is an indisputable winner in 3D rendering tasks. No wonder: this type of algorithms can be easily split into a few parallel threads.
In this review we tried to compare the processors from the mainstream pricing segment of the today’s CPU market. The situation here changed when Intel announced its dual-core Pentium D processors. The lowest model in this family working at 2.8GHz costs $241, and hence is qualified formally for use in typical mainstream computer systems. So now the users can choose not only between Athlon 64 and Pentium 4. Among the candidates for this position we now also have Intel Pentium D 820, which performance we have just compared against that of the other solutions falling into the $200-$300 range.
According to our tests, the launch of an inexpensive Intel processor can seriously affect the users’ preferences. Pentium D 820 appears faster than its single-core rivals in a pretty big number of test applications. Although this is mostly true for Pentium 4. Athlon 64 solutions retain their leadership in those tasks where they have been the best. But in many applications where the winner’s laurels used to belong to Pentium 4 CPUs, we now see Pentium D 820 raising the performance bar even higher.
So, with all certainty, we can recommend using the new Pentium D processors for multi-threaded environments and applications optimized for multi-processor systems. In this type of tasks, the new Intel dual-core CPU can show the best results. If you consider yourself a gamer or if you rarely use multi-threaded applications, you should still go for your ideal choice: Athlon 64.
As for the Pentium 4 processors, they sometimes appear faster than the dual-core Pentium D, but only in those tasks where the absolute leadership is already taken by Athlon 64. However, you should also keep in mind a few negative things about the new Pentium D 820. This is primarily the need to buy a new mainboard for it. Unfortunately, Intel’s dual-core newcomer is compatible only with new mainboards on i955/i945 chipsets. And these boards are still not so widely spread and cost quite a bit of money. So, it would be a way too early to cross out the good old Pentium 4, which doesn’t suffer from any compatibility issues.