Intel's Dothan Makes Its Late Debut

The New Dothan, Or The Evolution Of Banias, Continued

In addition, the new fabrication process allows significantly more transistors to fit in the same surface area. While the developers were able to put 77 million transistors, including the 1 MB L2 cache, onto an 82.8 mm² surface, Dothan now boasts 140 million transistors and a 2 MB L2 cache on a surface of only 83.6 mm². With nearly the same die surface, the number of transistors has increased by nearly 80%. The L2 cache takes up only 56% of the die surface.

Dothan die: With Dothan, the 2 MB L2 cache takes up more than half of the die surface...

Banias die:..with Banias, the 1 MB L2 cache took up only" 40%.

The strained silicon technology used for the Prescott also makes its "mobile" debut in the Dothan. This technology entails lightly stretching the lattice of silicon crystals in the area under the transistor gate, resulting in higher mobility of the electrons, which move through the canal between the source and drain electrodes. Because the electrons are more mobile, transistors fabricated this way can switch faster. When applied to a CPU, which represents nothing more than a huge collection of transistors, it is possible to produce processors that can be clocked to significantly faster speeds.

Theoretically, the use of 90-nm and strained silicon technologies, combined with a 2 MB L2 cache, should result in a fast and power-saving processor. This is also reflected by the value of the thermal design power, which Intel specifies at 21 watt for Dothan. On paper, the CPU thus consumes less power than its predecessor as well. Later on, we will see if this holds true in practice too.

Intel Pentium-M 755Intel Pentium-M 745Intel Pentium-M 735Intel Pentium-M 1.70 GHz
Processor Frequency2.00 GHz/ 600 MHz1.80 GHz/ 600 MHz1.70 GHz/ 600 MHz1.70 GHz/ 600 MHz
Package TypeMicro-FCPGAMicro-FCPGAMicro-FCPGAMicro-FCPGA
Transistors140 Mio.140 Mio.140 Mio.77 Mio.
FSB Speed100 MHz100 MHz100 MHz100 MHz
L1-Cache32 kB/32 kB32 kB/32 kB32 kB/32 kB32 kB/32 kB
L2- Cache2048 kB2048 kB2048 kB1024 kB
L2 Cache Speed2.00 GHz1.80 GHz1.70 GHz1.70 GHz
Bus/ Core Ratio20181717
Core Voltage1.340 V/ 0.988V1.340 V/ 0.988V1.340 V/ 0.988V1.484 V/ 0.956 V
Thermal Design Power21 W/ 7.5 W21 W/ 7.5 W21 W/ 7.5 W24.5 W/ 6 W
Sleep Power3.2 W3.2 W3.2 W1.7 W
Deep Sleep Power2.5 W2.5 W2.5 W1.1 W
Deeper Sleep Power0.8 W0.8 W0.8 W0.55W
Manufacturing process90 nm90 nm90 nm0.13 micron
Die Size84mm²84mm²84mm²83 mm²

Technical Data: Dothan vs. Banias

Intel left the speed of the front side bus (FSB) unchanged. The launch of Dothan models with a faster FSB of 133 MHz (533 MHz quad-pumped) are slated for launch in the second half of the year at the earliest. By then, a new platform, Sonoma, should be waiting in the wings, with plenty of new features that will be introduced in Wintel notebooks: dual-channel DDR2, PCI Express, DX9-capable integrated graphics, Intel high definition audio, the WLAN module Calexico 2 (a/b/g), ExpressCard and Intel Display Power Saving Technology 2.0 as well as Ambient Light Sense. Support for fast system memory will remain the same, with DDR 333/266 continuing as the standard.