Performance estimates: Almost a Pentium M at a fraction of the power
Despite the fact that Atom is a "good enough" processor in terms of performance and there is a clear focus on low power consumption, there's still the performance question: How fast is it?
Intel was very careful providing any exact data comparing the processor with other Intel CPUs or competing processors. We have seen some Intel slides with performance estimates and were able to take a few quick notes. Lucky us: Intel declined to provide the more interesting slides on an official basis and that is why you won't see many performance slides in this article.
So, we do have a few numbers, but remember to take these numbers with a grain of salt: Until there are official numbers from independent tests, these benchmark numbers are just indications how Silverthorne will perform.
In Intel's internal tests, Silverthorne's Spec_int2000 (an integer test benchmark) scores came in at 319, 439 and 653 points for models with clock speeds of 800 MHz, 1.2 GHz and 1.6 GHz (note that the 1.2 GHz is not a SKU that will be available for purchase). In comparison, a 1.86 GHz Core 2 Duo E6300 processor scores about 1900 points in this test. Intel said that Silverthorne's performance in this specific benchmark can increase by about 50%, if Hyperthreading is enabled. You can see an overview of Spec_int2000 test results here.
The floating point-focused Spec_FP2000 scores were 294, 402 and 582 points for these processors, which compare to about 1800 points that has been achieved by a (single core) 3.0 GHz Pentium 4 630 processor. You can see an overview of Spec_fp2000 test results here.
Intel estimates that Silverthorne processors without Hyperthreading will post about 126-130 points in the EEMBC v1.1 benchmark of the Embedded Microprocessor Benchmark Consortium, while the hyperthreaded versions will reach up to 172 points. It is difficult to compare the Silverthorne performance to other processors in this benchmark as there aren't many results for common processors available. The organization, however, lists AMD's 6 watt 1 GHz Geode processor with a score of 30.2 as well as Transmeta's discontinued 1 GHz Efficeon CPU with a score of 137.
Silverthorne will not be able to match the performance of the A110 CPU with the 90 nm Dothan core. Depending on their clock speed, the 800 MHz Atom CPU will be able to hit about 90% of the 3DMark2005 performance, about 70% of the Office performance and about 98% of the gaming performance. While this may sound disappointing for a new processor that is compared to a design that was introduced about five years ago, keep in mind that Silverthorne provides this performance at a power consumption that does not exceed 0.65 watts - while the 800 MHz A110 is currently rated at 5 watts.
In this perspective, the performance numbers are quite impressive.
Read on the next page: Market opportunity, Intel's challenges and conclusion