The Firmware Hub (FWH)
The i815 also brings over the same i82802 Firmware Hub (FWH) as used on i810 boards, and, once again, the explanation is pulled from our original i810 review:
As you can tell by the name, the FWH is essentially the BIOS of the motherboard. The FWH is a 4Mbit EEPROM device with a bit of "intelligence" to it in that it does more than just store/retrieve predefined and modified settings, the FWH also contains Intel's own Random Number Generator (RNG). Programmers will be able to access the RNG in order to use it in developing encryption algorithms for encrypting credit card numbers for online shopping. Intel's documentation claims that the RNG is used for "greater security," go figure, regardless, the RNG is there.
There is a downside to the FWH, it happens to operate synchronously with the 33MHz PCI bus. This translates into another factor you must consider when you are overclocking the PCI bus to any degree. Although your PCI peripherals may work fine at a PCI bus frequency greater than 33%, if the FWH does not agree then you'll be in a bit of trouble. AnandTech's tests revealed that the FWH on most 815 boards is fairly reasonable when it comes to out-of-spec operation, however we issue no guarantees (it's overclocking, c'mon).