My system, built in 1995, is a 133MHz Pentium. I believe that, generally, the PCI bus operates at 33 MHz. My harddrive is a WD 13.6 Ultra ATA/66 harddrive, which has the following speed capabilities: Transfer Rate (Buffer to Disk): 133.33 Mbits/s minimum (16.7 MB/s) 233.57 Mbits/s maximum (29.2 MB/s) Transfer Rate (Buffer to Host): 66.6 MB/s (Mode 4 Ultra ATA) 33.3 MB/s (Mode 2 Ultra ATA) 16.6 MB/s (Mode 4 PIO) 16.6 MB/s (Mode 2 multi-word DMA) I want to purchase an add-in ATA/100 controller card to obtain the maximum throughput for the drive, and to circumvent a 2.1 GB drive limitation. Question #1: In my current configuration (before installing the add-in ATA/100 controller card), is the "true-constant" flow of data across my system's IDE controller interface determined by the Internal Transfer Rate of 16.7 MB/s(Buffer to Disk -minimum), or by the External Transfer Rate of 16.7 MB/s(Buffer to Host - Mode 4 PIO)? Although both rates are identical in this case, generally speaking for my system, which Transfer Rate is the determining factor? Question #2: My hardrive can attain a theoretical maximum Burst Rate of 66.6 MB/s (Buffer to Host), with a 80-pin cable. If I purchase and install an ATA/100 controller will the actual throughput(Transfer Rate) between the harddrive and my system remain fixed by the Internal rate of 16.7 MB/s(Buffer to Disk -minimum), or will it reach the External Rate of 66 MB/s(Buffer to Host -maximum)? Question #3: Will the BIOS and Controller on the ATA/100 controller card override the current system throughput, and allow the External rate to reach 66 MB/s?

If your motherboard bus is ATA33 the ATA100 card won't go any faster than ATA33 and won't go past your BIOS limitations. The card may not work at all.

An ATA100 card will not solve your problems. I have a vx board with a greenie overdrive processor that I installed an ata66 controller card into. I cannot enable dma or data corruption results. These problems are endemic to using newer add-ons on older boards. Your best bet is to forget this particular upgrade.

Thanks TechTony and Junky_Toof. I think you guys may be right. I was just hoping that I could give sysem a "little kick". Once again, Thanks.

Thanks TechTony and Junky_Toof. I think you guys may be right. I was just hoping that I could give sysem a "little kick". Once again, Thanks.