Re: Pentium (R) Pro processor press release (fwd)
Sat, 04 Nov 95 12:32:02 +0000

> Hello,
> Thanks for the info. However, the DEC alphas according to INFOWORLD
> will have a 50% increase in speed (they didn't specify 50% in what),
> this could mean an increase from 300mhz to 450mhz. They did mention
> that the specint will be approx 500.
> I would like to add, what good is a fast microprocessor when the
> current ISA/EISA bus speeds ( and I presume the same for the PCI buses
> coming out) are no faster than 33mhz or less with DRAM access speeds
> still being at 60-70 nano-sec with no memory interleaving (i.e. a
> two way interleave would get two memory values for each access and
> make the 60 ns memory appear as if it were 30 ns. This is an old
> super computer memory trick). These are the current bottlenecks
> in home PCs and which are important for multimedia applications that
> require high I/O bandwidth, even hough the CPU's can crunch numbers
> faster. The onboard cache helps some, but I can't store a
> multi-megabyte compressed MPEG in this cache alone and therefore I
> need to depend on a fast disk with high I/O bus speeds.
> I'm waiting for the day when memory access times available in PC's
> approach 20ns or less: although RAM and DRAMs with these times are
> already available, but costly. I'm waiting for the day when all
> buses (disk,video, etc) run at a speed of at least 50% of the CPU
> clock speed. Therefore, with each increase in clock speed, the
> bus speed would also increase for the PC being sold to the consumer.
> I know what PC's can be designed to, if only the PC manufacturers
> would do it!
> Does anybody know of a PC that is being sold that runs at a
> bus clock speed greater than 33mhz?

Right now the Pentium-120Mhz chip runs the PCI bus at 60mhz. The Pentium-133Mhz chip runs the bus at 66Mhz, and the new
Pentium-150Mhz chip will run the bus at 60Mhz again being a clock 2.5x designed chip. Also I saw a motherboard on one of the pages of the
WWW, don't know it off hand, but this site is where you can pick your own pieces and build a machine. It was a "Pentium" designed
motherboard that would accept 20NS memory in MAIN MEMORY, and not just as a cache. The real interesting part was that the 20Ns memory they
offered didn't cost that much more than the 70ns memory!

> I realize alot of manufacturers spec their bus speeds only in terms
> of bytes/sec. This can be misleading considering that typical buses
> can be 16 and 32 bits wide ( 2 bytes and 4 bytes wide). Thus, if I
> took a 33mhz bus and made it 16 bits this would be (33mhz*2 bytes= 66
> Mbytes/sec) vs. a 32 bit bus (33mhz*4 bytes= 132 Mbytes/sec) and the
> numbers look great. But when are the bus clock speeds going to
> increase?
> Mike Sweger,


A VERY Happy OS/2 Warp User:


REMEMBER: Even with the fenominal sales of Windows '95, OS/2 is still the number one selling 32-bit,