Soyo SY-P4ISR (845 SDRAM) Mainboard
  The Pentium 4 was introduced 
    along with Intel's 850 chipset, not long ago it was the only solution available 
    for the Pentium 4; obligating people to use it without giving them choice 
    to go with an alternative solution. The 850 is Intel's high end solution for 
    the Pentium 4, mainboards based on the 850 cost more and use the more expensive 
    RDRAM memory. In order to spread the Pentium 4 more into the mainstream market, 
    an alternate chipset had to be introduced. 
    
    The 845 chipset is Intel's solution to get the Pentium 4 into the mainstream 
    market; the chip costs lower to produce, the new core logic allows mainboard 
    makers to get back to the lower cost four-layer PCB's and at the same time 
    takes use of the less expensive SDRAM or DDR SDRAM memory. We are looking 
    at the DFI NB72-SR; an 845 SDRAM based Pentium 4 mainboard.
    
  
     
      | Features | Info 
           | 
     
      | 
          Intel 845 Chipset6 PCI slots1 CNROnboard AudioSupports PC133 
            SDRAMAC`97 Audio codec 
            RAID 0 or 1Socket 478 |  | 
  
  Intel 845
   Intel introduced their 
    845 chipset earlier this year in order to accommodate their Pentium 4 with 
    a value segment chip which costs less to produce and eliminating the need 
    of using the expensive RDRAM memory. The South Bridge of the 845, ICH2, is 
    the same as in the high end 850 chip which supports 4 USB 1.1 ports, ATA/100 
    support, CNR/AMR slots and a 6 channel AC"97 audio along with a LAN interface. 
    
  The North Bridge features 
    support for the Pentium 4 processor running at 400MHz Quad Pumped Bus, supports 
    3GB of memory for PC133 SDRAM or 2GB of PC1600/PC2100 DDR SDRAM along with 
    AGP4X. Note that as Intel positioned the 845 as a value segment, ECC support 
    is not available on the memory controller. 
  The 845D (DDR) and 845 
    (PC133) versions offer the same features; both share the same ICH2 hub. The 
    only difference between the 845D (DDR) and the 845 (SDRAM) is the memory controller 
    which features support for DDR SDRAM. 
  
    
 
 
      Intel 845 Schematic 
   
  