North Bridge/IGP

RADEON 9100 IGP

ATI’s RADEON 9100 IGP supports the latest Prescott and Northwood Pentium 4 processors. The chipset supports front side bus speeds of 400/533/800MHz with a dual-channel memory architecture supporting the latest memory types. Single-channel operation is also supported, but for optimal performance you really should outfit both memory channels with memory, especially if you’re relying on the integrated graphics. Like Intel and SiS’ dual-channel Pentium 4 chipsets, the RADEON 9100 IGP supports up to 4GB of system memory (1GB per DIMM).

5 PCI Slots

Integrated into the North Bridge of the chipset is the 9100 IGP (integrated graphics processor). The RADEON 9100 IGP is based on a cut-down variant of the RADEON 9000. Whereas the RADEON 9000 features a four pixel pipeline architecture, with one texture unit per pixel pipeline, the RADEON 9100 IGP halves the number of pixel pipelines to two, with one texture unit per pipe (2x1). This is necessary to keep the complexity of the chip down, and also reduces cost. To help offset this, ATI has increased the core clock frequency to 300MHz, which is 25MHz above RADEON 9000 PRO, and also higher than NVIDIA’s IGP found in nForce2.

In another cost-cutting move, ATI has removed the hardware vertex shader unit from RADEON 9100 IGP. This functionality is instead performed by the CPU, so ATI can still claim DX8.1 compliance.

RADEON 9100 IGP’s memory interface is 128-bits wide, with a maximum capability of 128MB, which is shared with the system memory.

Like RADEON 9000, the RADEON 9100 IGP sports dual 400MHz DACs, so potentially the RADEON 9100 IGP could be used to drive dual displays (although this capability isn’t provided by the ASUS board). The chip also provides TV-out support, allowing you to output directly to your TV.

Isometric view

4 USB and 1 Firewire

Case switch jumpers

One area that did concern us was visual quality. Motherboard manufacturers have been known to skimp on this area in the past with their integrated solutions, but we’re glad to report that the display quality of the 2D portion of the 9100 IGP was quite good on the P4R800-V Deluxe, and actually looked better than a RADEON 9000 PRO card we received from Powercolor. The chip supports a maximum resolution of 2048x1536. All that’s really missing is DVI capability; the 9100 IGP needs an external DVI transmitter to provide this.

SURROUNDVIEW

One additional feature the RADEON 9100 IGP supports is SURROUNDVIEW. Once a discrete ATI graphics card is installed, the 9100 IGP can be used to drive up to three separate displays, the first in a system chipset. SURROUNDVIEW is supported by the entire RADEON 9x00 family (excluding the RADEON 9700 and RADEON 9100), and works with Built By ATI as well as Powered by ATI graphics cards from manufacturers such as Sapphire, ABIT, and ASUS. All you will need is the latest BIOS for your motherboard (ASUS’ SURROUNDVIEW BIOS is currently in beta) as well as ATI’s CATALYST 4.3 display driver.