ATI RADEON 9100 IGP Integrated Chipset Review

by Ilya Gavrichenkov
12/01/2003 | 11:02 PM

The recent advances of ATI Technologies are hard to overestimate. This VPU maker has fortified its positions in the graphics market during the last year and today ATI offers undoubtedly the best solutions in some price categories. The last year was also remarkable for ATI’s attempt to take the chipset market by storm. I’d like to remind you that ATI had already had integrated chipsets for mobile computers in its product range and some mainboard makers, for example FIC, even use them in mainboards for desktop PCs. That said, the ATI’s previous attempts to make chipsets can hardly be called a success. The RADEON 340M IGP and RADEON 320M IGP never really took off. Our today’s review is devoted to another attempt of ATI’s: the ATI RADEON 9100 IGP chipset.

Watching NVIDIA succeed at promoting its Socket A and Socket754 chipsets along with their GPUs, ATI chose to put more effort into conquering the chipset market. Since ATI has a license agreement with Intel, the choice of the platform was an easy one. The ATI RADEON 9100 IGP is for Socket478 processors. It’s also quite natural for the RADEON 9100 IGP to have an integrated graphics core – ATI is very experienced in producing inexpensive but efficient graphics cores.

Although the ATI RADEON 9100 IGP was announced quite long ago, we couldn’t get one for a review until now. The engineering team encountered problems when developing the South Bridge – ATI has to earn its chipset-making experience yet. The problems having been successfully solved, we can now test the newcomer in detail.

It should be noted that the new chipset from ATI drew furtive glances from many mainboard makers. The leading companies, including ASUS, MSI and Gigabyte, have already announced their intention to create RADEON 9100 IGP-based products. This is of course no indication of the real advantages and prospective success of the new chipset. After all, the users will decide whether ATI can become a competitor to Intel, VIA and SiS or not. Does the chipset have a potential to achieve this goal? We will check this out right now!

The Chipset

Glancing through the specs, you can’t see anything exceptional about the RADEON 9100 IGP. More to that, while the North Bridge is quite up-to-date, the South Bridge is closer to the chipsets of tomorrow. Here is the flowchart of the RADEON 9100 IGP:

Formally, the North Bridge supports Pentium 4 processors family with 400/533/800MHz FSB, contains an integrated graphics core, but is also capable of working with external AGP 8x graphics cards. The chip supports Hyper-Threading and features a dual-channel 128-bit memory controller supporting DDR400/333/266 SDRAM. It seems like these qualities make it a good alternative to Intel’s integrated chipset, i865G.

This is only a superficial impression, though. I should note that the support of the 800MHz Quad Pumped Bus and DDR400 SDRAM are dubious qualities of the RADEON 9100 IGP. At least, ATI didn’t dare to name them officially on the announcement of the chipset, but revised the specs later. Moreover, first mainboards on the RADEON 9100 IGP to appear didn’t support processors with the 800MHz FSB at all.

This problem was partially solved later. Off-the-shelf mainboards on the ATI RADEON 9100 IGP that have become now available do support the 800MHz QPB and DDR400. My experience with such mainboards tells me that this support is not universal and comprehensive. The new chipset from ATI sets strictest requirements to the memory modules working at 400MHz. Some DDR400 SDRAM modules just don’t work at their specified frequency with the ATI RADEON 9100 IGP, while others can only be used with loose timings. For example, the Corsair XMS3200LL memory we use often in our tests feels all right with Intel’s chipsets at 400MHz and with 2-2-2-5 timings, but is only stable in RADEON 9100 IGP-based mainboards with 2-3-3-8 timings. So, some problems with the memory controller in the North Bridge turn to be more persistent than expected and declared.

The North and South Bridges of the ATI RADEON 9100 IGP are connected via the proprietary A-Link bus that provides a bandwidth of 266MB/s. In its previous chipsets, ATI used to link the Bridges with the PCI bus, but its bandwidth is too low according to the today’s standards. The change of the bus also forced ATI to develop their own South Bridge called IXP250 (the previous chipsets from ATI came with South Bridges from ALi, but this trick is no longer possible).

The IXP250 South Bridge is scanty in its functions. My deepest sorrow was about the missing SerialATA/150 support: we have already got used to seeing it in modern chipsets. Seems like ATI has got some problems with this function, just like NVIDIA. Otherwise, the ATI IXP250 South Bridge supports six USB 2.0 ports, two ATA/100 channels and six-channel AC’97 audio. The network capabilities of the IXP250 are implemented by means of an integrated 3Com 10/100 Ethernet controller. Overall, ATI took it easy when developing this South Bridge. Some useful capabilities are simply missing, some are implemented by using third-party controllers. By the way, I have some reasons to think that the ATA/100 controller in the ATI IXP250 comes from Intel, too.

Besides the IXP250, ATI offers two alternative South Bridges connected to the A-Link bus: IXP150 and IXP200. These two chips are simplified versions of the IXP250, featuring no power-saving functions. The IXP150 is also devoid of the network controller. ATI promises to release one version of the South Bridge with the so badly needed SerialATA support. According to ATI, it is going to appear in the first quarter of 2004.

Thus, it is only possible to build an inexpensive mainboard using the regular functionality of the RADEON 9100 IGP chipset. That’s in fact normal for a chipset with an integrated graphics core. IEEE1394 (FireWire) and SerialATA interfaces can be implemented on such mainboards by means of extra onboard controllers, but that would mean higher product cost.

At the same time, the ATI RADEON 9100 IGP is the second chipset with an integrated graphics core to claim for the title of “Its High Performance”, since it supports Hyper-Threading, the 800MHz QPB and dual-channel DDR400 SDRAM. These qualities make ATI’s chipset a direct rival to the i865G. Let’s compare their characteristics:

The integrated graphics core is one of the trumps of the ATI RADEON 9100 IGP chipset. The architecture of the graphics core resembles the RADEON 9200 VPU and it makes the RADEON 9100 IGP look advantageous compared to integrated chipsets from other manufacturers.

Before we start discussing the 3D capabilities of ATI’s chipset, I would like to say a couple of words about 2D graphics. Thanks to the 400MHz RAMDAC, this RADEON supports a maximum resolution of 2048x1536x32bit with 85Hz refresh rate. A refresh rate of 100Hz is available in the more common mode, 1600x1200x32bit. This results in a superb 2D image quality (against many other integrated chipsets). The image is crisp and sharp even in the highest supported resolutions. Of course, the engineering team included support for hardware DVD decoding. The chipset features enhanced DVD playback options, including hardware iDCT and motion compensation. It should also be mentioned that the ATI RADEON 9100 IGP supports TV and DVI outputs without any additional chips or daughter cards.

As for 3D, the ATI RADEON 9100 IGP is undoubtedly the most advanced integrated chipset of today. For example, it is the only one to support DirectX 8. The NVIDIA nForce2 and Intel 865G cannot boast this quality as they only support DirectX 7. In order to put things in a perspective, I have built a table with the graphics core of the RADEON 9100 IGP set against the Intel Extreme Graphics 2 core from the i865G:

I think the table is self-explanatory: the ATI RADEON 9100 IGP is beyond competition as far as functionality is concerned. It is also one of the strong points about ATI’s chipset that it is highly compatible with a majority of games. Added the support of the ver.1.4 pixel shader, RADEON 9100 IGP can handle most of the current games (I hope you are aware that the i865G cannot run quite a number of computer games).

As for the performance of this graphics core, ATI tried to boost it up by optimizing its operations with the memory. Modern integrated chipsets are allocated graphics memory from the main RAM. Thus, the graphics core becomes yet another active consumer of the memory bus bandwidth. That’s why graphics data compression technologies are heartily welcome. This may provide a hefty performance gain, since performance of Unified-Memory-Architecture chipsets in 3D is often limited by the low memory speed.

The RADEON 9100 IGP has an exclusive and curious thing to offer: Surroundview. The mainboards on this chipset can work with three monitors if you use an external graphics card. That is, the chipset-integrated graphics core remains enabled even after you install an external add-on graphics card. The most peculiar thing about this technology is that it doesn’t actually work, although some mainboard makers have been advertising it hard. There arose some problems with its practical implementation, so the mainboards on the RADEON 9100 IGP to arrive in the near future will force the disabling of the integrated graphics after installation of an AGP 8x card.

Testbed and Methods

We tested the new integrated chipset from ATI in two steps. First, we checked out the performance level of the RADEON 9100 IGP with the integrated graphics core. Then, we installed an external graphics card and ran the tests once again. This also helped us estimate the efficiency of the chipset memory controller.

The chipset itself came to us on a new mainboard from Sapphire, AXION 9100 IGP (RS300-MA26).

As you see, this MicroATX mainboard features the RADEON 9100 IGP and the IXP150 South Bridge. This product is evidently targeted at the lower end of the market and has just the necessary set of functions (USB 2.0, ATA-100, AC’97, 10/100Mbit Ethernet) and a minimum of expansion slots (3 PCI, 2 DIMM and AGP 8x). Even such ordinary functions as hardware monitoring or Ethernet support are optional for the AXION 9100 IGP. On the other hand, this has cut the price of the mainboard to about $70. And for this small money you get a mainboard with an integrated graphics core and support of the topmost processors!

Of course, it would be wrong to demand any exclusive features from Sapphire. It’s only necessary for this mainboard to provide stable work of the system and it may become popular among PC integrators and users who want to purchase an inexpensive system. The AXION 9100 IGP handles the task well enough. We can present no stability-related complaints about this product.

We also took a mainboard on Intel’s integrated chipset to be a kind of reference point. This was an i865G-based mainboard from the same Sapphire Company.

As a second reference point (to compare it to the chipsets’ performance with an external graphics card), we chose a mainboard on the discrete Intel 865PE chipset.

Overall, the testbed configuration looked as follows:

• Intel Pentium 4 3.2GHz CPU (800MHz QPB);
• Sapphire AXION 9100 IGP (RS300-MA26), Sapphire 865GMS4-A10 and ASUS P4P800 mainboards;
• 2x256MB Corsair XMS3200LL memory;
• NVIDIA GeForce FX 5900 Ultra graphics card (Detonator 52.16 driver);
• Western Digital WD400JB HDD.

The testbed ran under control of Windows XP Professional SP1 with DirectX 9.0b installed.

Performance

We are going to check out the performance of the integrated memory controller first. The ScienceMark 2.0 test set will help us to measure the bandwidth and latency of the memory subsystem.

The memory controller of the RADEON 9100 IGP is less efficient than its counterpart from the Intel chipsets for several reasons. First, the RADEON 9100 IGP requires less aggressive memory timings to be set up. Second, the memory controller itself is far from perfect – the engineering team from ATI doesn’t have much experience at developing system chipsets.

There is one peculiar thing about the results. The integrated chipsets (i865G and RADEON 9100 IGP) suffer differently from activation of the integrated graphics cores. While the i865G experiences a perceptible bandwidth reduction and higher latency, the memory controller from ATI is less vulnerable. This is probably due to the graphics core from ATI loading the memory bus less as it uses compression algorithms applied to the data pumped along the bus.

Note also that the i865PE shows higher speed than the i865G even when the external graphics card is used. Although these two chipsets don’t differ in their internal architecture, the difference is clear. I think the chipsets have nothing to do with this, for this is the mainboard’s fault. Mainboard manufacturers don’t think it necessary to optimize the BIOSes of their products on the i865G, since they are targeted at budget systems. That’s why i865G-based mainboards are slower than their mainstream counterparts: they come with average internal timings and without even mentioning the PAT support.

Now, let’s turn to applications that don’t use 3D graphics.

The Winstone tests show how fast the system is in office and content-creation applications. And they also show that the RADEON 9100 IGP is speedy enough. The main contributor to this result is the IDE controller, sitting in the South Bridge. Its efficiency matches the IDE controller from the ICH5.

Data compression and encoding performance depends mostly on the memory controller. When the integrated graphics cores are in use, the RADEON 9100 IGP performs as fast as i865G. When we install an add-on AGP card, ATI’s chipset falls behind the i865G.

The next round of tests is connected with the performance of the integrated graphics core of the RADEON 9100 IGP.

The ATI RADEON 9100 IGP shows its best in the 3DMark2001 SE test set. The i865G tries to look competitive in the first two tests and only in 640x480 resolution, thanks to the higher clock-rate of its graphics core. In higher resolutions the RADEON 9100 IGP shows much higher results as it uses the memory bus more efficiently. The third gaming test, Lobby, uses vertex shaders, which are much better implemented in the RADEON 9100 IGP than in the i865G. That’s why ATI’s chipset wins in all resolutions in this test, including the lower ones. As for the Nature test, it requires DirectX 8 support from the graphics core, which the i865G cannot provide. So, this test simply doesn’t run on Intel integrated chipset.

3DMark03 suggests that it’s not quite fair to run modern computer games on integrated chipsets. Although the DirectX 8 tests launch and run on the RADEON 9100 IGP, the speed is simply depressing. As for the single DirectX 7 text, Wings of Fury, the RADEON 9100 IGP wins it thanks to its high-quality vertex shaders support and the ability to map six textures per clock cycle.

It’s funny, but Intel’s chipset is faster in Quake 3 than the RADEON. This is the only 3D test to rank the chipsets this way. The higher frequency of the i865G core together with the relative simplicity if the gaming engine (it doesn’t use vertex shaders or all six TMUs of ATI’s chipset) must have led to this situation.

ATI’s chipset is much faster than the competitor in the more modern Unreal Tournament 2003.

The same is true for Serious Sam: The Second Encounter.

We have come to the second part of the testing. We upgrade the systems by installing an external NVIDIA GeForce FX 5900 Ultra graphics card and get them run through the tests once again.

As you see, the RADEON 9100 IGP profits but little from the upgrade. The weakness of the memory controller integrated into this chipset makes it perform slower than Intel’s chipsets in games when the external AGP 8x card is used.

Conclusion

The results of our today’s tests suggest that the current ATI Technologies’ attempt to enter the integrated chipset market has a chance to become a lucky one. The new chipset, RADEON 9100 IGP, features a high-quality integrated graphics core, which provides good compatibility with current games and high performance (for its class). The performance is enough for you to play comfortably a 3D game of the previous generation in resolutions up to 1024x768. Thus, the ATI RADEON 9100 IGP suits well as a foundation of an inexpensive system.

As for the prospect of a future upgrade, there may be problems. Although the RADEON 9100 IGP supports the newest Socket478 processors and features an external AGP 8x port, its performance after installation of an external graphics card can hardly be called satisfactory. Unfortunately, the memory controller that resides in the RADEON 9100 IGP is slow and badly-compatible with DDR400 SDRAM. As a result, RADEON 9100 IGP-based mainboards fall behind analogous products that are based on competitor chipsets.

Summing it up, I’d say that this chipset should become popular exactly as an integrated solution, considering the low price of the mainboards based on it. It will sure find its way into small form-factor PCs and inexpensive systems. At the same time, ATI Technologies has a long time yet to become a really successful chipset maker. If it were not for the graphics core, the ATI RADEON 9100 IGP wouldn’t grab any interest at all. The ATI engineering team has to learn yet how to develop and optimize memory controllers and improve South Bridges. I hope the next chipset from this manufacturer will be higher-performing and also hope that it will arrive in the near future rather than in a year or two.