A brief chipset look
Before we begin our review of the ST61G4 in usual HEXUS fashion, it would be prudent to take a concise look at exactly what the Radeon 9100 IGP chipset brings to the table and how ATI reckons it is an Intel i865G-beater.We could write volumes about how it supports this feature, or how it does incorporates that useful technology. The best way of desibing and evaluating the 9100 IGP is to compare it directly to the chipset that it will compete against. So a table that highlights the specifications of both the i865G and 9100 IGP should suffice. We'll pay specific attention to the IGP incorporated into the ST61G4.
| Chipset | ATI Radeon 9100 IGP (ST61G4) | Intel i865G |
| North Bridge | RS300 | i865G |
| South Bridge | IXP 150 | ICH5 (R) |
| FSB Support | 800 / 533 / 400MHz | 800 / 533 / 400MHz |
| Maximum CPU support | 3.2GHz*, H-T support | 3.2GHz*, H-T support |
| Memory support | DDR400 / 333 / 266 / 200 Dual Channel | DDR400 / 333 / 266 / 200 Dual Channel |
| Bandwidth limit | 6.4GB/s | 6.4GB/s |
| Maximum RAM limit | 4GB | 4GB |
| AGP rate | 8x (AGP3.0) | 8x (AGP 3.0) |
| Bridge interconnect speed | 266MB/s | 266MB/s |
| USB Ports | Up to 6 USB 2.0 | Up to 8 USB 2.0 |
| Storage | 2-channel IDE ATA100 | 2-channel IDE ATA100 + 2-port SATA 150 |
| Other | Integrated 3COM Ethernet controller | Optional MCH-attached LAN |
| Onboard graphics | 9100 / 9200-like | Extreme Graphics 2 |
| O/B specs. | 2 rendering piplelines / 1 texture unit per pipe | Unknown |
| Max Mem Usage | 128MB | 64MB, Dynamic Allocation |
| DirectX | 8.1 | 7 |
| Shading | PS1.4 in hardware. Vertex shading in software | None |
| Core speed | 300MHz ? | 266MHz |
| AA / AF | 6x AA / 16x AF | 2x AF ? |
| Display | 2 x 400MHz RAMDACs, TV-Out (1024x768), 1600x200 for LCDs | 2 x 350MHz RAMDACs, TV-Out (1024x768), 1600x1200 for LCDs |
Ignoring the integrated GPUs for a second, both the RS300 and i865G North Bridges are startlingly similar. ATI has managed to replicate Intel's dual-channel (2 x 64-bit) memory controller. That's a potential 6.4GB/s of bandwidth with the supported 200MHz (800MHz QDR) CPUs. Both chipsets feature an identical interconnect speed but the Intel ICH5 (or ICH5R) manages to eke ahead with on-chip SATA support, something that's not present in the IXP150. It's clear that the ATI Southbridge is a little lightweight on the features front. ATI may counter this by stating the intended market is looking for value more than features. In that case, if the RS300 / IXPxxx combination can be priced aggressively and produced by first-tier manufacturers, it may well have a future. We state that with some confidence because the integrated graphics are leagues ahead of the comparison i865G's. It's difficult to obtain hard-and-fast specifications on the Intel Extreme Graphics 2, but after having used it and its predecessor over the past year or so, I can say that it's lacking in pure grunt and specs.
This isn't a GPU review. We'll conduct our usual motherboard-related benchmarks. Suffice to say, ATI's Radeon 9100 IGP looks impressive enough on paper. The question is whether the transition between paper and decent tangible performance comes over intact.
