100mhz bus frequency Chipsets features comparison

Intel 440BX AGP Chipset

The Intel ® 440BX AGPset includes the 82443BX Host Bridge and the 82371EB PIIX4E for the I/O subsystem. The 82443BX features include: • Support dual Pentium II processor configurations • Support full symmetric Multi-processor (SMP) • 64-bit GTL+ based Host Bus Interface • 32-bit Host address Support • 64-bit Memory Interface optimized for PC100 SDRAM • 32-bit Primary PCI Bus Interface (PCI) with integrated PCI arbiter • AGP Interface (AGP) with 133 MHz (X2) data transfer capability • Mobile and "Deep Green" Desktop power management support

The following block diagram shows a typical platform based on the Intel ® 440BX AGPset. The 82443BX host bus interface supports up to two Pentium II processors at the maximum bus frequency of 100 MHz. The 82443BX provides an optimized 64-bit DRAM interface. This interface is implemented as a 3.3V-only interface that supports only 3V DRAM technology. Two copies of the MA, and CS# signals drive a maximum of two DIMMs each; providing unbuffered high performance at 100 MHz. The 2443BX provides interface to PCI operating at 33 MHz. This interface implementation is compliant with PCI Rev 2.1 Specification. The 82443BX AGP interface implementation is based on Rev 1.0 of the AGP Specification. The AGP nterface supports 133 MHz (AGP 2X) data transfer rates and can be used as a Secondary PCI interface operating at 66 MHz/3.3V supporting only a single PCI agent.

As you can see the BX Chipset is not very different of a LX Chipset. The main difference between the LX and BX Chipsets is that the later support a bus frequency of 100mhz, Does this make a great performance improvment? Not realy, because the L2 cache is installed on the CPU cartridge on the slot 1 Pentium II architecture it is clocked and half the CPU frequency so cloking the CPU to 4.5 times 66mhz or 3 times 100mhz for a PII 300mhz will give the same final results with a L2 cache frequency of 150mhz, so, there are no real performance gain here ! However, if used on Socket 7, this chipset would give a real boost to the L2 cache memory because on these motherboards the memory is clocked at 66mhz, therefore, 100mhz bus speed representing a 50% incrrease in speed over the standard 66mhz bus architecture this should give a real good push to the L2 cache memory especially when used with PC100 SDram memory.

The Aladdin Pro II is a new generation Pentium II class system Chipset. It consists of two BGA packed chips, the M1621 and M1533 or M1543. The M1621 is an AGP, memory and I/O controller and a data path with multi-port buffers for data acceleration. With an external I/O APIC controller, it can support multiple Pentium II processors.

The M1533 provides a bridge between the PCI bus and ISA bus. It includes power management unit, ACPI, deep green function, 2-channel dedicated Ultra-33 IDE master controller, 2-port USB controller, SMBus controller, and PS2 Keyboard/Mouse controller. The M1543 integrates ACPI, green function, 2-channel dedicated Ultra-33 IDE Master controller, 2-port USB controller, SMBus controller, PS/2 keyboard/mouse controller and Super I/O (Floppy Disk Controller, 2 serial port/1 parallel port) support.

Aladdin Pro employs various techniques to improve the memory and I/O throughput to match up with the advanced super-scalar, super-pipelined Pentium II class processors. On the memory subsystem side, the Pentium II data bus utilization is minimized. The pipelined memory cycle design helps hidden precharge latency and refresh cycles. Different ways of configurations optimize the performance for a wide range of memory size. On the I/O subsystem side, deep buffers shadow the latency for both PCI devices initiated master read and write. To support the 3D graphics function, M1621 supports a 66 Mhz graphics PCI bus, and 1x/2x AGP mode.

VIA Apollo Pro supercedes VIA's Apollo P6 (introduced in 1996) and is the industry's first available alternative Slot-1 core logic chipset. The north bridge chip of the new chipset is called the VT82C691. Complimenting VIA's new Apollo Pro north bridge core logic chip is a new south bridge, the VT82C596, which also upgrades the Apollo MVP3 Socket-7 chipset (VT82C598MVP), introduced Jan 14, 1998.

The Apollo Pro is a two-chip set supporting both desktop and mobile designs. It consists of the (VT82C691) north bridge controller and the also new (VT82C596) south bridge. The north bridge features 100MHz support for Slot-1 processors. It also provides synchronous and pseudo-synchronous CPU/AGP/PCI operation and support for the full range of currently available DRAMs including PC100 SDRAM.

The new VT82C596 south bridge supports both Socket-7 and Slot-1 PC system designs and is the first device offering support for the emerging ATA-66 disk drive interface standard. ATA-66, also known as ULTRA DMA 66, effectively doubles drive data transfer rates. The new south bridge also provides PC98 ACPI, UDMA and USB support. It works with the advanced power management features of VIA's currently available north bridge chips including suspend-to-DRAM and independent clock controls for system buses.

By reading the informations and comparing the features of this Chipset we can easily see that this Chipset is the most advanced and the most feature packed of all available Pentium II slot-1 logic cores !

The following table summarize all the features of the 440BX Chipset and compares
it to the VIA Apollo Pro and Ali Aladdin Pro II Chipsets which are both 100mhz Chipsets.