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- From: mccall@mksol.dseg.ti.com (fred j mccall 575-3539)
- Subject: Re: EISA/MCA *or* Local Bus? Which is better for multitasking?
- Message-ID: <1992Dec18.190607.445@mksol.dseg.ti.com>
- Organization: Texas Instruments Inc
- References: <BzBx9G.Ap@utdallas.edu> <1992Dec17.231538.29868@blkbox>
- Date: Fri, 18 Dec 1992 19:06:07 GMT
- Lines: 54
-
- In <1992Dec17.231538.29868@blkbox> rbarnett@blkbox (Rick Barnett) writes:
-
- >goyal@utdallas.edu (MOHIT K GOYAL) writes:
-
-
- >>Hello.
-
- >>I am curious as to which is better for OS/2, EISA/MCA or VL-Bus.(Vesa Local Bus)
-
- >>Here is my setup:
- >>single user on a stand alone pc.
-
- >>that's pretty much it.
-
- >>I will be running lotsa programs..games, word processors, Pascal, Mathcad,
- >>whatever else.
-
- >>Anyways, I would like to know which would offer better performance.
-
- >EISA is 32 bits wide with bus mastering but only runs at 8 MHz. Video and
- >hard disk controller cards are few and expensive.
-
- 8.33 MHz vice 8 MHz.
-
- >VESA is 32 bits wide with bus mastering and runs at CPU speed (up to 50 MHz).
- >A fair number of manufacturers have announced or already produce VL-Bus cards,
- >and the prices aren't much higher than the ISA versions of the same
- >cards.
-
- Usually only 40 MHz on most systems. There are restrictions on how
- many VL devices you can have if you try to go faster than that.
-
- >>Also, does it even matter? (ie-if EISA/MCA is much better, will it matter?
- >>will I ever make full use of Local Bus, or vice versa?)
- >>I plan on having a scsi-2 hard drive and a scsi cd rom.
-
- >I have seen specs on two VL-Bus SCSI controllers, with data transfer rates
- >up to 66 MBytes per second - since SCSI-2 maximum is 10 MB/sec, you can hang
- >a few drives on it without saturating the I/O channel.
-
- EISA will transfer 33 MB/s. Somehow I don't see this difference being
- germane insofar as SCSI devices go, since you can't get EFFECTIVELY
- more than 10 MB/s down the SCSI chain anyway (only one drive can talk
- to the controller at a time - the higher figures are BURST rates).
- The difference is that while your VL controller is doing its transfer,
- everybody else on the VL bus has to stop. This isn't true for EISA.
-
-
-
- --
- "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.
-