Introduction
Intel flexes their muscles and shows their technological dominance in the low-cost chipset arena. Up to date there have been a several attempts to design a fully integrated chipset. Unfortunately, this type of integration in the past went hand-in-hand with lack-luster 3D performance. Most of the integrated chipset solutions shipping now provide acceptable performance for productivity software (e.g. word-processing, home finance, and Internet browsing). But when the user would slap their favorite 3D game title in to the CDROM drive instead of entering a cartoon like 3D world with full motion video it was more like a watching a slide-show. The reason for horrible 3D performance was due to the video implementation in the chipset. Most of these integrated chipset solutions use UMA (Unified Memory Architecture) where the integrated video allocates the required frame buffer from the system memory. By sharing the system memory the integrated video is limited to slow 66MHz-memory access. This slow memory access along with rudimentary 3D features integrated into most of these chipsets equated to HORRIBLE 3D gaming. Finally, Intel has provided the 810 Chipset solution to meet the low price demands of consumers without completely ignoring the performance requirements of 3D gaming.
No ‘North’ and ‘South’ Anymore, Only Hubs!
The Accelerated Hub Architecture
Over are the good old days of ‘North’ and ‘South’ bridge, Intel ‘invented’ the new “Accelerated Hub Architecture”!! Now I cannot really say that I ever really understood the point of ‘North’ and ‘South’ bridges on motherboards, since it would be news to me that you adjust your motherboard according to North and South like Muslims praying towards Mecca. However, the question may be raised why Intel is changing this sweet little naming of the two chips that make a chipset to the ‘HUB-architecture’. The main deal about this new architecture is that the two main chips are not connected using the PCI-bus, but a new dedicated bus that offers double the bandwidth of PCI. Thus each device, including the PCI bus can directly communicate with the CPU, the memory controller and, in case of the Intel810, with the graphics controller as well, using an eight bit wide bus clocked at 133 MHz at ‘2x-mode’, which provides a bandwidth of 266 MB/s. The Intel820, well known under the name ‘Camino’ right now, will also use this hub-architecture.
In the below chart you can see the different architectures:
66MHz or 100Mhz?
Now there are a lot more buses used within the Intel810-chipset. The picture below can show you the different interconnections:
The CPU Bus or ‘Front Side Bus’ – 66 MHz , 64 bit = 533 MB/s
Above all you can see the CPU, a Celeron processor. Here comes the first questionable thing about 810. Due to the fact that Intel hasn’t released any Celeron CPUs at 100 MHz front side bus yet, the 810-chipset communicates with current Celeron processors at 66 MHz only. The 810 has a built in switch that cranks up the FSB to 100 MHz, but officially this is not supposed to happen as long as the Pentium III is only using 100 MHz FSB as well. As soon as the Camino chipset is available, PIII will move to 133 MHz FSB and Celeron will finally get to 100 MHz FSB. This will be the time when Intel will suddenly ‘enable’ 100 MHz FSB in the 810-chipset. This issue is very interesting for overclockers, because most motherboard makers will include a jumper or maybe even a soft switch on the board that let’s you switch between 66 and 100 MHz FSB already now.
The ‘GMCH’ and its Buses
The 82810-chip is called ‘GMCH’, which stands for ‘Graphics & Memory Controller Hub’. The name already says it, this chip includes the memory controller and the 2D/3D graphics engine of the 810-chipset. The GMCH has three external buses and one interesting internal bus, the above picture shows unfortunately only two external ones.
- The Memory Bus – 100 MHz, 64 bit = 800 MB/s
Surprisingly, Intel is running the memory bus at 100 MHz in 810, although the CPU-bus is only 66 MHz for now. This means that 810-boards will require PC100 memory, even though you plug in only a 66 MHz CPU. The memory bus is pretty straight forward, 64 bits wide, clocked at 100 MHz, thus offering a bandwidth of 800 MB/s, which is 50% more than the CPU bus bandwidth of only 533 MB/s. I guess this is the first time in PC-history, that the memory runs at a faster bus than the CPU, but who shall ever understand the logic of mighty Intel? A CPU is using an internal L2-cache clocked at processor clock and thus up to 466 MHz, to buffer the slow external bus of only 66 MHz, whilst the memory could deliver data faster at 100 MHz if this 66MHz slow motion street wasn’t in between them. - The ‘Interlink’ Bus between GMCH and ICH – 133 MHz, 2x, 8 bit = 266 MB/s
We talked about it already, the graphics & memory controller hub is connected to the ‘ICH’ = ‘I/O Controller Hub’ using a special bus that offers 266 MB/s bandwidth, which is pretty cool and fast. - The Internal ‘Direct AGP’ – 100 MHz, 64 bit = 800 MB/s
You can imagine it quite well, the 810-chipset doesn’t come with an external AGP-connector, since its graphics controller is within the chipset already. Now it’s no real big deal for the graphics controller to use textures from main memory or receive geometry data from the CPU, since it is on the same chip as the memory controller. Thus it can talk to main memory at the full 800 MB/s, which is faster than the 533 MB/s of AGP 2x. However, we shouldn’t forget that the frame buffer of the 810-graphics is also found inside the main memory, and here the 800 MB/s look pretty pathetic compared to 3,200 MB/s and more local memory bandwidth, found on today’s 3D accelerator cards.
- The Display Cache Bus – 100 MHz, 32 bit = 400 MB/s
The 810 can be equipped with an optional display cache of 4 MB. This cache is only supposed to be used in 3D-applications for the Z-buffer. Now I am seriously wondering why this bus comes with a bandwidth of only 400 MB/s. The Z-buffer of a normal 3D-card is residing within its local memory and thus accessible at 3.2 GB/s and above. 400 MB/s is even less than the main memory bandwidth, so that I wonder why 810 is supposed to run faster 3D-graphics when using external display cache at 400 MB/s, instead of using a Z-buffer from inside main memory at a peak bandwidth of 800 MB/s without display cache.
The ICH
Right underneath the ‘GMCH’ you can find 82801, the ‘ICH’ = ‘I/O Controller Hub’. This part of the chipset talks to all the PCI-devices over the PCI bus, to the EIDE hard drives over either ATA33 or an ATA66 interface, to external devices over the USB, to a low priced modem/audio-codec via AC97 and finally to the ‘FWH’ = ‘Firmware Hub’. The ICH is the place where all the outside communications run together, forwarded to main memory, the CPU or the integrated graphics controller over this new 266 Mb/s bus.
The FWH – 82802
Behind the name ‘FWH’ = ‘Firmware Hub’ you’ll find a chip that’s not much else than a 4 Mbit EEPROM plus a tiny bit of active silicon. The EEPROM contains the motherboard and graphics BIOS and the active silicon is a random number generator. Intel is currently making a big mystery out of this random number generator, supposedly because there isn’t any software available yet. We all may guess what this little thing is supposed to be for.
The Different Flavors of the Intel 810-Chipset
Intel sells the 810 in three different versions, as shown in the graph below:
As you can see, you get to three different flavors by mixing GMCH0/GMCH and ICH0/ICH with each other in different combinations. GMCH0 does not support the external display cache and is thus supposed to be slower in 3D-applications. GMCH can be equipped with external display cache, but it doesn’t have to. ICH0 supports only 4 PCI slots and only ATA33, whilst ICH can run with up to 6 PCI slots and use ATA66 to talk to EIDE hard disks.
- i810-L
This is the cheapest version for super low cost motherboards. It comes at $23, can’t be equipped with display cache, the EIDE hard drive can only use ATA33 and the motherboard can be smaller, because there is no sense in more than 4 PCI slots. - i810
This version costs $27. There’s also no option for a display cache, but you get the full-blown I/O-hub with support of up to 6 PCI slots and ATA66 for the EIDE drive. - i810 – DC100
Don’t ask me what the ‘DC100’ stands for, but this version costs $30 and it’s the ‘high end’-version of i810. The only difference to the normal i810 is the option for a display cache, which is supposed to speed up 3D-graphics.
The Graphics of i810
Most of us believed that ‘Whitney’ would be ‘ZX plus i740’, but this is certainly not the case. I’ve already explained the hub architecture and now I’ll try and say some words about the 2D/3D graphics part. We were told that i810 is actually equipped with the core of Intel’s upcoming low/mid end graphics chip i752, the long overdue successor of i740. There’s not much that I can tell you about this chip, except that it’s also using a dual rendering pipeline and that its performance will be somewhere around TNT. This is all not really exciting, but it means that i810 is the first chipset with integrated 2D/3D-accelerator that has two rendering pipelines and could thus offer some pretty decent 3D-performance. Hold it, I am not saying that any 3D-gamer will be satisfied by this chipset, but people who want a low-cost system don’t have to refrain from the occasional 3D-games anymore. We are currently testing i810-motherboards in our Californian lab, and the 3D-performance we see is surprisingly good.
Another component of i752, which is included into the i810, is hardware motion compensation for MPEG2-decoding, so that i810 should also be good at playing DVDs.
The strongest performance inhibitor of the i752-core in i810 is certainly the memory bandwidth. i810 is using main memory for the frame, texture and Z-buffer, unless the Z-buffer can take advantage of the external display cache. Local memory on a graphics card can be accessed by the 3D-chip at a much higher bandwidth than the 800 Mb/s of the PC100 SDRAM main memory of i810. This is why you will not be able to conclude that i752 will be as ‘slow’ as the graphics engine of i810.
At boot up the graphics controller of i810 reserves 1 MB of main memory for the basic display buffer. As soon as the GUI-operating system runs, the graphics controller requires 4 MB for frame buffer, 2 MB of command buffer and 4 MB of Z-buffer, unless the system is equipped with the 4 MB of external display cache for this purpose. This means that either 7 or 11 MB of main memory are used by the integrated graphics, and the highest 3D-resolution will be 1024×768.
Other New Features of i810
You have certainly already realized that i810-motherboards will not come with an AGP-slot. This means that you can only ‘upgrade’ to a different graphics solution by plugging in a PCI graphics card, which is pretty pointless nowadays. The next thing that’s missing on i810-boards are the ISA-slots. Many of you will be happy about that, ISA’s days are over indeed. Additional serial devices can be hooked up to the USB, so that there’s indeed no reason for ISA anymore. Another new feature of Intel’s latest chipsets i810 and the upcoming i820 is ‘AC97’. This ‘port’ requires only an external modem/audio-codec, which won’t cost much more than 10 bucks, to offer sound as well as a 56k-modem. However, be alarmed that these are no active devices as a modem or sound card from the good old times. AC97 lets the CPU ’emulate’ a modem or a sound card, thus putting threat onto the CPU. Intel doesn’t like anything better than ‘innovations’ that require more CPU-horsepower, so that they can sell more of their CPUs. The result is that your CPU is so busy supplying enough power to the AC97-soft modem and the AC97 soft sound controller that your online 3D-gaming experience is getting close to zero. However, what am I talking about? The i810 is anyway not the right chip for online 3D-gaming, is it?
Summary
i810 is certainly the first reasonable chipset solution with integrated 2D/3D-graphics. The previously released and competing SiS620 chipset could not really satisfy anyone with its poor 2D/3D-performance and the bad 2D-quality. It wouldn’t be an Intel product if there weren’t any cheesy issues like the 66 MHz CPU front side bus, but all in all the features of this chipset look pretty promising. One thing that’s quite strange for Intel is the fact that current GMCH-chips are only in ‘close to final’ A2-stepping. This means that Intel isn’t ready to ship final silicon yet, although the product has already been announced! The promises say however, that i810-systems will be shipping by end of May / beginning of June 1999. i810 Motherboards are supposed to be as cheap as 50 to 60 bucks, Celeron CPUs are getting cheaper every day as well, most boards will offer a chance to overclock the FSB to 100 MHz and a AC97 modem/sound-device will cost around 10 bucks. This way you can get a system with 2D/3D-graphics, the ability to do DVD-playback, a modem and sound for very little money. The following part two of this i810-article will be able to give you a very good idea of what the performance will be like.
