i82845e Chipset

   Intel’s latest chipset, the i845e is, a good companion for the Pentium 4. Technically the i845e supports both Intel Celeron (starting at 1.7 GHz) and Intel Pentium 4 processors (including 533 MHz P4B). If the i845e supports Pentium 4 with a 533 MHz front side bus it doesn’t unleash the full potential of this processor since the supported DDR memory isn’t able to offer a 4.2 GB/s bandwidth. The main advantage of the i845e is its native support of the popular DDR-SDRAM memory that remains much more affordable than the expensive Rambus while providing good performance. With a new 82845e Memory Controller Hub, the i845e chipset is able to support PC1600, PC2100 memory. Officially Intel i845e chipset doesn't support -yet- the high end PC2700 (equal to DDR333) memory. However some manufacturers like Asus offer support of the DDR333 memory on i845e motherboards through the BIOS. For information the PC2700 DDR memory offers a 2.7 GB/s bandwidth against 2.1 GB/s for PC2100.

Intel Pentium 4 & Intel i845e Chipset

The i845e comes with the brand new ICH4 southbridge 82801DB component providing native support for the emerging USB 2.0 standard with up to 6 USB 2.0 ports. The ICH 4 also supports Gigabit-Ethernet: motherboard makers that want to offer an embedded ethernet solution will be able to use Intel’s very own 82854GC companion chip to provide support for 10/100/1000 Mbit/s network. Finally the ICH4 provides an integrated AC’97 audio solution supporting 7 channels. Other than that, the soutbridge supports UDMA 100 (and not UDMA 133 since Intel prefers to adopt Serial ATA) and AGP 4x.

USB 2.0 Backgrounder

Massively adopted by every computer user, the Universal Serial Bus standard has almost replaced the old school serial port because of its numerous yet undeniable advantages. The promoters of the USB worked hard to deliver a connecting norm that features serious qualities: hot plug, plug & play, plus the ability to connect 127 devices simultaneously. However USB as we know it today has one weak point; the interface offers a slow transfer rate. With USB 1.1’s poor transfer rate it was impossible for manufacturers to consider releasing USB storage devices like hard disks, USB high speed burners, USB network adapters, USB video capturing devices, etc.  

That’s why the members (Compaq, Intel, Hewlett Packard, Microsoft, Nec, Philips, etc.) of the USB Implementers Forum have co-developed a new promising generation of the USB norm extending performance by up to 40 times over existing capabilities. USB 2.0 features all the qualities of today’s USB but above all it offers an extraordinary bandwidth of 480 Mbps against only 12 Mbps for USB 1.1, thus unveiling new possibilities to connect high speed and high demanding devices. Today many USB 2.0 devices are available like hard drives, scanners, burners, etc.   

As stated before, the main advantage of the USB 2.0 is its unprecedented bandwidth. With a 480 Mbps bandwidth, the USB 2.0 beats the theoretical 400 Mbps bandwidth offered by the FireWire standard. Obviously the D850EMV2 motherboard is backward compatible with thousands of USB 1.1 devices; this means you can still connect and use your USB 1.1 equipments with the card. However, USB 1.1 devices connected on a USB 2.0 controller will work only at 1.5 Mbps or 12 Mbps. Just like its predecessor you can connect up to 127 USB devices to the USB 2.0 ports of your motherboard (you can combine USB 1.1 & USB 2.0 devices).   

As hot and exciting as it sounds, USB 2.0 has some drawbacks! Indeed you’ll have to change your existing USB hubs if you want a hub that offers full speed USB 2.0 connectors. Moreover, connecting a USB 1.1 hub to the USB 2.0 port of the D845EBT motherboard will limit the speed of your USB devices to the maximal speed of 12 Mbps that the USB 1.1 offers. Plus you have to use special USB 2.0 branded cables to connect USB 2 devices to the adapter, otherwise the USB 2.0 devices will operate in USB 1.1.