System configuration is determined more by the motherboard, not the processor. A 450 MHz Pentium III was only available in a Slot 1 package, and operated on a 100 MHz FSB. All other specifications of a system (chipset, memory, sound, hard drive, etc...) are dictated by other factors.
The processor has nothing to do with how large a hard drive is supported. Most Pentium III-era motherboards / BIOSes support up to 137 GB hard drives. You have thus likely not installed the drive correctly.
I've yet to encounter an AT motherboard that supported a Pentium III processor. All the same, it is possible to run Solaris 10 on a Pentium III computer. You'll need at least 256 MB of RAM, however.
The fastest "classic" Pentium is clocked at 200 Mhz. The fastest Pentium with MMX extension is clocked at 300 Mhz. The fastest Pentium II is clocked at 400 Mhz. The fastest Pentium III is clocked at 1.4 Ghz. The fastest Pentium 4 is clocked at 3.8 Ghz. The fastest Pentium D is clocked at 3.7 Ghz. The fastest Pentium M is clocked at 2.26 Ghz. The fastest Pentium Dual-Core is clocked at 2.5 Ghz.
Pentium III was created in 1999.
There is no "Pentium R" processor. Knowing this, the biggest difference is that the Pentium III exists and the other does not.
The L1 cache in the Pentium III is SRAM.
The Intel Pentium III was released on February 26, 1999.
Yes.
No, you cannot.
As a whole, the Pentium 4 has a higher maximum performance than a Pentium III. The Pentium III performs the same as or better than Pentium 4 at the same clock speed, but the Pentium 4 has a higher max clock speed (which the Pentium 4 was designed for).
The AMD K6-III and early Athlon processors are roughly equivalent in speed and performance. Via C7 processors, although released much later, are close in terms of performance to a Pentium III.
That will depend on the motherboard and BIOS. If the board supports a 100 MHz Front Side Bus and has the proper microcode updates, a 1.1 GHz Pentium III (using a Slotket) is possible. If the board is limited to only 66 MHz, a 450 MHz Pentium II, or a 500 MHz Celeron is about all you can do. It may be possible to install a Pentium III even then, but it will run underclocked and likely not run much faster than the 500 MHz Celeron.