The story of Intel chipsets for P6 CPUs is extremely instructive. Starting from i440FX, the first chipset announced simultaneously with Pentium Pro, and up to the victorious i440BX, Intel had never had any problems with the public acknowledgement of its new products and the market welcomed each of them with arms wide stretched. AGP, 100MHz FSB, PC100 SDRAM - Intel kept adding new stuff to its products little by little. However, one of Intel's last chipsets for high performance systems suffered a total fiasco. Trying to influence the market and to make the users turn to RDRAM for their desktop PCs, Intel stumbled. Neither the manufacturers, nor the users were ready for drastic changes like that, which were moreover connected with quite tangible spendings, because SDRAM and RDRAM cost differed by nearly 3-5 times. Besides, Intel failed to launch its i820 in time and the supplies of this notorious chipset were postponed now and then.

So, the things with the chipsets stood not in the best way for Intel. Cheap i810 and i810E equipped with the integrated graphics core and aimed at Low-End market sector immediately turned out much more popular, than the mainstream i820 because they supported SDRAM. And since Intel's positions here appeared pretty weakened, VIA took advantage of the situation and started winning more and more popularity and users' trust due to its successful Apollo Pro133 and Apollo Pro133A.

In this case Intel couldn't but indulge the users' desires and provide i820 with SDRAM support. However, adding SDRAM support couldn't be carried out that easily. So, the maximum Intel could think of, was to add another microchip, which would be responsible for interaction between i820 and SDRAM, namely for the interaction between SDRAM and RDRAM. As a result, this combination of absolutely different architectures led to extreme performance worsening of the entire system and its awful instability, so that Intel had to call back this unsuccessful solution. So this attempt of i820 to meet the customers' requirements ended up in failure.

Watching the ordeals of its newly born baby it suddenly occurred to Intel that the world needed another chipset supporting SDRAM, namely, its latest modification - PC133 SDRAM. Unfortunately, i440BX, which kept rendering obedience, started getting morally outdated, because it was unable to support the whole bunch of modern features, such as AGP 4x, PC133 SDRAM, UltraDMA/66 and the most significant drawback: it didn't support 133MHz FSB.

Well, this was a brief prehistory, which should explain why we got one more chipset at our disposal: Intel 815 (Solano). So, let's take a look at i815 main features compared to its major competitors.

As you can see from the table, i815 is a fully-fledged successor to i440BX. It also looks quite nice even against the background of VIA Apollo Pro133A. The only thing that makes us feel on guard is very small system memory: only 512MB compared to 1GB by competing products. But nothing to do with it, i815 is based on i810E and it is the bad heredity of i810E that tells. Both chipsets use Accelerated Hub Architecture, which Intel is currently implementing in all its newest chipsets.

The main idea of Accelerated Hub Architecture is very simple and looks as follows. The chipset South Bridge is in charge of IDE-devices support, AC'97 sound, network and other peripheral stuff and of course, it also needs memory access. So, the bandwidth of the bus connecting it with the North Bridge, which contains the system memory controller, should be high enough to transfer the data between the bridges at normal rates. When the South Bridge used to be a conventional PCI-device and was connected to the North Bridge by means of the conventional PCI bus, the bandwidth provided made 133MB/sec. Today this is too slow. Take, for instance, a new ATA/100 HDD interface: it allows transferring the data along either of the two IDE-channels at 100MB/sec. As you see, a new bus providing higher bandwidth between the South and North Bridges is badly needed. That's why Intel introduced Accelerated Hub Architecture, so that the bus between these two bridges has finally become able to provide the bandwidth of 266MB/sec.

Now the chipset is composed of two main hubs:

• Intel 82815 Graphics and Memory Controller Hub (GMCH)
• Intel 82801AA or Intel 82801BA I/O Controller Hub (ICH or ICH2)

and of an additional FWH, which is simply a flash-memory microchip.

Now let's discuss each of the hubs in a bit greater detail.

Intel 82815 Graphics and Memory Controller Hub

GMCH of Intel 815 chipset includes a memory controller and an integrated graphics core and provides interface with the CPU, system memory and external AGP 4x port.

As for the integrated graphics, nothing has changed here compared to i810. i815, like its predecessor, features the old i752. Here, however, it works at 133MHz and doesn't have the display cache, which can be installed into the AGP slot as a Graphics Performance Accelerator if necessary. As far as the performance is concerned, it hardly got any better, i.e. it remained at the level of the second-generation graphics accelerators, which is even slower than NVIDIA Riva TNT. If you'd like to learn more about i752, you may take a look at our i810 Review and i810E Review.

Speaking about the memory controller, we should bear in mind a few peculiarities. Intel has finally managed to implement PC133 SDRAM support in its chipset. However, since i815 is based on i810, the new chipset supports only 6 memory banks, which is only 3 DIMM slots. Moreover, it supports these 3 slots only as PC100. If you want to get the promised 133MHz memory working frequency, you will have to restrict yourself to 2 memory modules (4 banks) only. As soon as you get the fifth bank, the system automatically changes the memory frequency to 100MHz.

Like its counterpart, VIA Apollo Pro133A, i815 can clock the memory asynchronously with the FSB, however, even in this case the restrictions also appear inevitable. If your CPU uses 66MHz or 100MHz bus, the memory will work only at 100MHz, nothing more. But if you install a CPU supporting 133MHz FSB, the memory can be clocked for 100MHz as well as for 133MHz. As you see, unlike i820, our hero also supports 66MHz CPUs, i.e. Celeron. This once again proves that Intel aims its i815 at a low-cost systems market rather than at high performance desktop PCs.

Intel 82801BA I/O Controller Hub

Mainboards with GMCH i82815 can have one of the following two microchips for the second hub, as in case of i820: Intel 82801AA (ICH1) or Intel 82801BA (ICH2). The first one, ICH1, should be already familiar to you from the previous Intel chipsets with hub architecture. Among its major features we would like to point out the following:

• Features 33MHz PCI bus compatible with the specification version 2.2;
• Supports up to 6 PCI slots;
• Provides power management;
• Fulfils the functions of DMA and IRQ controllers as well as those of a timer;
• Has an integrated IDE-controller with Ultra ATA/66 interface support;
• Supports 2 USB-ports;
• SMBus compatible with most I2C devices;
• Has a special out port for AC'97-compatible audio and modem codec;
• Supports LPC (Low Pin Count) interface;
• Supports FWH interface;
• ICH allows wake on LAN feature.

Well, you should be familiar with all these functions already, and for details on ICH1, please, check our Intel 820 Review. The only thing we would like to add here is the absence of ISA bus support, though you may still see ISA slots on i815 based mainboards. They are implemented through the external PCI-to-ISA bridge.

And now a few words about ICH2. This chip is the next piece in ICH family and offers a bit more functions than ICH1. The first and the most important thing about it is the fact that it supports new IDE ATA/100 interface, which we have already discussed in our ATA/100 Investigation. This interface allows increasing the theoretical burst transfer rate between the memory and the hard drive. And although the today's hard disk drives cannot reach 100MB/sec transfer rate in real practice, the performance gain provided by ATA/100 interface in case of smaller files multiple access stored in the HDD buffer is quite tangible.

The second important innovation in ICH2 is the integrated network controller, Intel 82559, which allows implementing 10/100 Ethernet or HomePNA. In other words, you shouldn't be surprised to see the network connectors on the mainboard built on Intel 815. And if there are none of them, you may install a small riser-card into CNR slot (developed from AMR, but not pin-compatible with it, unfortunately).

Besides, we should also point out 4 USB ports (compared to 2 USB ports in ICH1) and 6 AC'97 channels support (compared to 3 channels in ICH1).

As for FWH, it remained unchanged since the times of i810 that is why we won't describe it once again here.

Performance

And now comes the most interesting moment of our review: the tests. We are really anxious to find out the performance of i815, because it will show whether i815 can be defined as a real successor to i440BX chipset.

For our tests we took a mainboard on Intel 815, D815EEA. This mainboard of ATX form-factor is provided with Socket 370 and supports FC-PGA Intel Celeron and Intel Pentium III. Besides AGP slot, there are 3 DIMM slots, 5 PCI slots and 1 CNR slot. The integrated sound on D815EEA is implemented by means of the integrated PCI sound controller from Creative Labs. The mainboard supports new ATA/100 HDD interface, because it has ICH2.

We compared the performance of this mainboard with that shown by a mainboard built on i440BX (ASUS P3BF), a mainboard built on i820 (AOpen AX6C-L) and a mainboard on VIA Apollo Pro133A (Chaintech 6ATA4). For our tests we used a CPU supporting 133MHz FSB that's why the mainboard on i440BX worked in non-nominal mode and its AGP frequency was set to 89MHz (note that the nominal AGP frequency is 66MHz). Other than that the testing system was configured as follows:

• Intel Pentium III 933 CPU;
• Creative 3DBlaster Annihilator Pro graphics card;
• Creative Sound Blaster Live! sound card;
• IBM DJNA 372200 HDD;
• 128MB PC133 SDRAM by Micron (in systems on i440BX, VIA Apollo Pro133A and i815);
• 128MB PC800 RDRAM by Samsung (in the system on i820).

And now let's pass over to the results. At first let us offer you the performance in office applications in MS Windows 98SE.

According to this test, which shows the average performance in typical content creation applications, the leader is i815. Then comes i820, which owes this high performance to RDRAM system memory with its high bandwidth.

Here the situation is a bit different, because the test uses a wide range of typical office applications. However, i815 again appears the leader, proving that it has the best memory controller of all. Even the unexcelled i440BX fell a couple of points behind our newcomer.

For a better idea of the performance, take a look at a more detailed chart:

Well, the chart speaks for itself, no doubt. And now let's turn to games.

To estimate the AGP quality, we made use of Quake3 demo, which transfers large textures. To our great disappointment i815 performed not too well, however, we may blame the drivers and BIOS imperfection for this failure. i820 managed to take the lead again due to high bandwidth provided by RDRAM.

A standard Quake3 test at low resolution shows that the overclocked i440BX working with the 133MHz FSB is ahead of all.

And in Unreal Tournament, which loads the entire system including the processor bus quite heavily, i815 left its competitors behind.

The lower gets the resolution, the lower gets the graphics subsystem workload, however, the situation on the outcome chart remains the same.

If you want to get a clearer picture of this chipset working with the memory, run Expendable. Here, as you can see, Intel 815 showed the best of it. Don't be surprised at the low results shown by i820: Expendable doesn't require data streaming that's why RDRAM is powerless.

And at 640x480x16 i440BX beats everybody, though just a bit.

Of course, the performance in NT-like operation system, such as Windows2000, is also pretty interesting. So, take a look:

Strange as it might seem, but as soon as we changed the OS, i820 lost the game. Our i815, however, proved as good as before in Windows2000. Here are the results shown in SYSmark 2000 applications:

Moreover, we decided to take the performance of our chipsets in a synthetic test called SPECviewperf, which models the work of the system in different applications dealing with 3D-rendering.

When working with 3D-animation all systems proved very close to each other. However, we still detected a certain gap between i440BX and the rest.

3D-modeling also didn't show any significant differences. Only VIA Apollo Pro133A fell behind the leaders this time.

The scientific visualization of the physical model appeared the easiest to carry out for i820.

Lighting calculation is another trump of i820. This chipset seems to fit most nicely for professional OpenGL graphics due to RDRAM and its high bandwidth. i815 runs neck and neck with i440BX here.

The designer's industrial software package is also not the best thing for i815 to show off. However, as you have probably noticed, i815 proved very cool everywhere except the professional OpenGL graphics, where i820 took an indisputable lead. But nothing to be surprised at, actually. High-End i820 is, of course, the best solution here.

In conclusion we would like to say a few words about the integrated graphics core. In fact, its performance is not that impressive and is somewhere close to that of the two-year old graphics cards. But on the other hand, the user gets it almost for free. That is why you can certainly regard it as a temporary solution. Especially, since it is more than enough for 2D.

So, it seems pretty logical to compare the integrated graphics core of i815 with other integrated graphics cores. The main direct competitor here appears a new chipset from VIA - ProSavage PM133.

VIA ProSavage PM133 is a joint achievement of VIA and S3, which is a combination of VIA Apollo Pro133A chipset and S3 Savage4 graphics controller. We had a chance to look at the prerelease sample of a mainboard on VIA ProSavage PM133, which gave us a certain general idea of the integrated graphics core features. So, we compared the performance of i815 based board with that shown by VIA ProSavage PM133, when working with the integrated graphics controllers.

As you can notice, i815 performs quite well in 2D graphics. Even if we compare this result to the performance shown with the external graphics card used, the performance drop will make only 2-3%, which is quite cool. As for the ProSavage PM133, the things stand a bit worse.

However, in games VIA ProSavage PM133 takes its revenge. In 3D graphics VIA's guy proves over 50% better than its competitor. That is why if you get a mainboard on VIA PM133, you will be able to play any modern game at 800x600, while with a mainboard on i815 it is absolutely impossible.

Conclusions

Well, let's sum up. If we judge by the testing results, the conclusion will be more than evident: new Intel chipset is a success. Disregarding the professional OpenGL graphics, i815 won 6 of the 10 tests. That is why here it is undoubtedly a good successor to i440BX, especially since it supports low-cost PC133 SDRAM. Besides, it is deprived of i440BX drawbacks: it features 133MHz FSB support, AGP 4x and new IDE ATA/66 and ATA/100 interfaces support as well.

At last there appeared a new Intel chipset, which has every chance to become the sales hit. i820 cannot cope with this role because RDRAM is too expensive, and VIA Apollo Pro133A is lagging behind in many tests. The only cause for concern remains the price of i815. The chipset costs about three times as much as VIA Apollo Pro133A, for instance. So, the mainboards may turn out at least $30 more expensive.

And we should keep in mind that the integrated graphics core of i815 performs not quite well in 3D. So don't rely on it here.

Though everything seems so beautiful for i815, this may last not that long. By the end of the year VIA should announce its new Apollo Pro 2000 supporting DDR SDRAM. This solution is supposed to show much higher performance than the systems with PC133 SDRAM. That is why VIA has a really good chance to continue its expansion into the mainstream chipsets market.