Thursday, July 27, 2000

The i815 (continued)

The memory

The i815's memory controller, for its part, supports asynchronous memory bus speeds of 66MHz, 100MHz, and 133MHz. Of course, according to Intel, the 133MHz option can only be used in conjunction with processors that support a 133MHz FSB. That means, while it's possible to work with an FSB of 66MHz, and a memory bus frequency of 100MHz using PC100 memory, it's not possible to use PC133 memory on a 133MHz memory bus on with a CPU FSB operating at 100MHz.

Another odd bit of information, also from Intel, makes it clear that it's not possible to use as much PC133-rated memory as would be possible with slower PC100 memory. The i815 can apparently support 6 PC100 memory banks (3 DIMMs), but only 4 memory bank (2 DIMMs) when working with PC133 memory. According to Intel, if more than 2 DIMM sockets are occupied with PC133 memory operating on a 133MHz memory bus, the system pulls some levers, and reduces the memory bus speed down to 100MHz.

This of course brings back not-so-find memories of Intel's notorious problems with the i820 chipset. In that case, manufacturers were warned that a bug in the chipset made systems unstable if more than 2 RIMM connectors were put to use at the same time.

To terminate, note that the i815 only supports up to 512MB of memory, while the i820 & Via Apollo Pro133A chipsets can support up to 1024MB. By all appearances, the i815 is not meant to be used in high-performance systems such as servers, but rather as a solution for smaller, domestic systems.

The I/O Controller Hub(ICH)

The i815 uses much the same ICH as did the i810 chipset; the i82801AA. The i82801AA supports PCI, USB, AMR, and ATA33/66 - though not ATA100, which is only supported by the i815E chipset. So, you may be slightly disappointed to hear it, but the i815 will not be able to take advantage of your shiny new ATA100 hardrive...

The i815E set employs the 802BS chip - better known as "ICH2" - which is also used by the i820. The ICH2 not only supports ATA100, but also a v1.1-compliant USB controller, which means it can support up to 4 USB ports. Other than that, we'll leave further discussion of the i815E for a latter date, as it's not immediately relevant to this particular review.

So, to sum up the features of the ICH1:

It supports a 33MHz PCI bus that is compliant with the PCI 2.2 standard, supports up to 6 PCI slots, controls all IRQ & DMA routing, supports compatibility with SMBus, and features Wake-On-LAN

Finally, while the i815 does in fact support the addition on an ISA slot, it is highly unlikely that you'll actually see a board on the market that features one, unless it is through the use of a PCI-to-ISA bridge.

The Firmware Hub (FWH)

Essentially, the Firmware is the motherboard's personal ID. The i815's Firmware is the i82802, which it shares in common with the i810. It is a 4MB EEPROM, synchronized with the PCI bus at 33MHz, and includes an RNG, which is a sort of random number generator that Intel claims increases security.

Conclusions concerning the i815

By all accounts, the i815 was parachuted into the chipset war as a sudden attempt by Intel to face down the Via Apollo Pro133A. For some time now, Intel has lacked the proper weapon with which to compete with Via's starring player, and that left Intel's gargantuan share of the chipset market up for grabs. Our analysis of the i815 set, though, reveals that Intel's counter-effort may have been a bit too rushed, and as a result, support for PC133 memory is limited. Not to alarm anyone too much, but it looks like we may still be waiting a while before we see the perfect chipset, heheh :). In other words, while the 440BX chipset was a high end chipset for both desktop and office computers, the i815 and i815E looks more fitted to low end systems or if you prefer, no the i815 is really not a worthy successor of the 440BX...

Next: Features of the PT-815TX.