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- Newsgroups: comp.sys.ibm.pc.misc
- Path: sparky!uunet!cs.utexas.edu!csc.ti.com!tilde.csc.ti.com!mksol!mccall
- From: mccall@mksol.dseg.ti.com (fred j mccall 575-3539)
- Subject: Re: EISA Board Compatibility
- Message-ID: <1992Sep14.220211.24415@mksol.dseg.ti.com>
- Organization: Texas Instruments Inc
- References: <1992Sep8.173226.10860@scott.skidmore.edu> <1992Sep10.183339.18855@mksol.dseg.ti.com> <1992Sep11.131232.7977@scott.skidmore.edu>
- Date: Mon, 14 Sep 1992 22:02:11 GMT
- Lines: 35
-
- In <1992Sep11.131232.7977@scott.skidmore.edu> pvonk@scott.skidmore.edu (Pierre VonKaenel) writes:
-
- >In article <1992Sep10.183339.18855@mksol.dseg.ti.com> mccall@mksol.dseg.ti.com (fred j mccall 575-3539) writes:
- >>In <1992Sep8.173226.10860@scott.skidmore.edu> mfrazer@scott.skidmore.edu (Matthew Frazer) writes:
- >>
- >>>EISA Boards have faster bus speeds to the card slots, but do I need to
- >>>buy all new EISA compatible cards, or can I use my old
- >>>cards in the EISA slots?
- >>
- >>They are not significantly faster (8.33 MHz vice 8 MHz). The whole
- > ^^^^^^^^^^^^^^^^^^^
- >>idea behind EISA was that you could plug all your old cards into it
- >>and they would work. They do. There are, in fact, some things that
- >>you would be hard pressed to find an EISA card for.
-
- >Now I *am* confused! I thought I just read a long thread last month
- >about EISA and how much faster the bus is, but some folks were worried
- >that putting an ISA card in the EISA machine would slow down that bus.
- >8.33 vs. 8 doesn't seem that much faster, and I'd swear the numbers
- >used for EISA were much higher. Anyone?......
-
- This is one of those urban myths. Transfers for EISA cards in EISA
- slots are much faster because you can do 32-bit wide transfers.
- Hence, the burst bandwidth is 33 Megabyte/sec (4 byte wide by 8.3
- MHz clock -- someone else recently posted that the actual EISA clock
- speed is 8.25 MHz). Plugging ISA boards into an EISA bus doesn't slow
- down anything, except that that board will run slower than an
- equivalent EISA board would.
-
-
- --
- "Insisting on perfect safety is for people who don't have the balls to live
- in the real world." -- Mary Shafer, NASA Ames Dryden
- ------------------------------------------------------------------------------
- Fred.McCall@dseg.ti.com - I don't speak for others and they don't speak for me.
-